Uster Countum 3 6n145n

USTER QUANTUM 3 ®

Application Handbook

Yarn clearing on winding machines

Textile Technology / V1.0 / April 2011 / 316 050-10020

Contents

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Table of contents Status

Foreword

04.2011

1

Introduction

04.2011

2

Basics of yarn measurement and yarn clearing

04.2011

3

Disturbing thick- and thin places

04.2011

4

Count variations

04.2011

5

Splice clearing

04.2011

6

Periodic yarn faults

04.2011

7

Quality parameters of a yarn

04.2011

8

Foreign fibers

04.2011

9

Vegetable Matter Clearing

04.2011

10 Detection of polypropylene fibers with USTER® QUANTUM 3

04.2011

11 Various settings and applications of USTER® QUANTUM 3

04.2011

12 Clearing of special yarns

04.2011

13 The first hour at the new clearer system

04.2011

14 Frequently asked questions

04.2011

15 Technical specifications

04.2011

16 Appendix

04.2011

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Editorial team: Dr. Serap Dönmez Kretzschmar Ulf Schneider Richard Furter Peter Schmid

© Copyright 2010 by Uster Technologies AG. All rights reserved. All and any information contained in this document is non-binding. The supplier reserves the right to modify the products at any time. Any liability of the supplier for damages resulting from possible discrepancies between this document and the characteristics of the products is explicitly excluded.

April 2011

veronesi\TT\Schulung Dokumente\On-Line\Garnreiniger\UQ3\ApplicationHandbook_UsterQuantum3

USTER® QUANTUM 3

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Table of contents 1

2

3

Introduction............................................................................................................................ 1.1 1.1

Purpose of the application handbook ....................................................................................... 1.1

1.2

Yarn faults and yarn clearer ....................................................................................................... 1.1

1.3

Short history of the USTER yarn clearers ............................................................................... 1.3

1.4 1.4.1 1.4.2

Origin of seldom-occurring yarn faults ..................................................................................... 1.5 Separation of frequent and seldom-occurring yarn faults .............................................................. 1.5 Distinction between frequent and seldom-occurring yarn faults .................................................... 1.6

1.5

Classification of seldom-occurring thick and thin places ....................................................... 1.7

1.6

Allocation of seldom-occurring yarn faults to the Classimat matrix...................................... 1.8

1.7 1.7.1 1.7.2

Structure of the USTER QUANTUM 3..................................................................................... 1.11 ® Features of USTER QUANTUM 3 and options .......................................................................... 1.12 Features versus measuring head types ...................................................................................... 1.13

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Basics of yarn measurement and yarn clearing .................................................................. 2.1 2.1

Purpose of this chapter .............................................................................................................. 2.1

2.2 2.2.1 2.2.2 2.2.3 2.2.4 2.2.5 2.2.6

Monitoring of thick places .......................................................................................................... 2.1 The capacitive measuring principle ............................................................................................... 2.2 The optical measuring principle ..................................................................................................... 2.2 Yarn signal definitions .................................................................................................................... 2.3 Characteristics of the two measuring principles ............................................................................ 2.5 Environmental influences on yarn measurement and yarn clearing .............................................. 2.6 Selection of the suitable measuring principle ................................................................................ 2.7

2.3 2.3.1

Monitoring of foreign fibers in the yarn .................................................................................... 2.7 Characteristics of the sensor for foreign fibers .............................................................................. 2.8

2.4 2.4.1 2.4.2 2.4.3 2.4.4

Communication of the yarn clearer with the winding machine .............................................. 2.9 Zero point adjustment .................................................................................................................... 2.9 Calibration process on a running yarn ........................................................................................... 2.9 Yarn detector ............................................................................................................................... 2.11 Winding speed ............................................................................................................................. 2.13

Disturbing thick and thin places........................................................................................... 3.1 3.1

Introduction .................................................................................................................................. 3.1

3.2

Definition of the yarn body ......................................................................................................... 3.1

3.3

Interpretation of the yarn body .................................................................................................. 3.5

3.4 3.4.1 3.4.2

Disturbing thick places ............................................................................................................... 3.5 Classification matrix ....................................................................................................................... 3.5 Thick and thin places ..................................................................................................................... 3.7

3.5 3.5.1 3.5.2

Clearing limits for thick places .................................................................................................. 3.9 Standard way of optimizing clearing limits: Manual clearing limits entry ..................................... 3.10 Setting a smart clearing limit for disturbing thick places (NSL) ................................................... 3.11

3.6 3.6.1

Disturbing thin places ............................................................................................................... 3.14 Classification matrix ..................................................................................................................... 3.14

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3.7 3.7.1 3.7.2

Clearing limits for thin places .................................................................................................. 3.14 Standard way of optimizing clearing limits: Manual clearing limits entry ..................................... 3.15 Setting a smart clearing limit for disturbing thin places (T) .......................................................... 3.17

3.8 3.8.1 3.8.2 3.8.3 3.8.4

The effect of thick and thin places on the fabric appearance ............................................... 3.19 Thick places ................................................................................................................................. 3.19 Reasons and measures to minimize seldom-occurring thick places ........................................... 3.24 Thin places .................................................................................................................................. 3.25 Reasons and measures to minimize seldom-occurring thin places ............................................ 3.27

Count variations .................................................................................................................... 4.1 4.1

Introduction .................................................................................................................................. 4.1

4.2

Definition of the yarn body for long-term variations (C and CC faults) ................................. 4.1

4.3 4.3.1 4.3.2 4.3.3 4.3.4

Count deviations.......................................................................................................................... 4.3 Determination of the mean value of a yarn .................................................................................... 4.3 Purpose of yarn count deviation monitoring................................................................................... 4.3 Monitoring of yarn count deviations during start-up in the C – channel ......................................... 4.4 Monitoring of the yarn count while winding with the CC-channel ................................................... 4.5

4.4 4.4.1 4.4.2

C and CC settings ........................................................................................................................ 4.6 Yarn count deviations at start up (C) settings ................................................................................ 4.6 Setting a smart clearing limit for yarn count monitoring (CC) ........................................................ 4.8

4.5 4.5.1 4.5.2 4.5.3 4.5.4 4.5.5

Calculation of yarn count deviations ....................................................................................... 4.12 Determination of count deviations with the clearer installation .................................................... 4.12 Calculation of the count deviations of wrong bobbins (capacitive measurement) ....................... 4.13 Calculation of count variations of wrong bobbins – optical measurement ................................... 4.15 Calculation of count variation of wrong bobbins with a diagram .................................................. 4.16 ® Relationship between the mass and diameter deviation with the USTER Calculator ................ 4.17

4.6

Example for the setting of the C-channel ................................................................................ 4.18

4.7 4.7.1 4.7.2

The effect of count deviations on the fabric appearance ...................................................... 4.19 Mixing two different yarn counts .................................................................................................. 4.19 Reasons and measures to minimize count variations ................................................................. 4.23

Splice Clearing ...................................................................................................................... 5.1 5.1

Introduction .................................................................................................................................. 5.1

5.2

Scatter plot of splices ................................................................................................................. 5.1

5.3 5.3.1 5.3.2 5.3.3 5.3.4

Splices .......................................................................................................................................... 5.3 Visual appearance ......................................................................................................................... 5.3 Practical example .......................................................................................................................... 5.4 Basic principles of splicing ............................................................................................................. 5.6 Wet Splicing ................................................................................................................................... 5.7

5.4

Splice classification of the USTER QUANTUM 3 .................................................................... 5.8

5.5 5.5.1 5.5.2

Clearing limits for splice clearing (Jp and Jm) ......................................................................... 5.9 Standard way of optimizing clearing limits: Manual clearing limits entry ....................................... 5.9 Setting a smart clearing limit for splices (Jp/Jm) ......................................................................... 5.10

5.6

Upper yarn detection (U) ........................................................................................................... 5.13

5.7

Minimizing the number of splices ............................................................................................ 5.14

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5.7.1 5.7.2 5.7.3 5.7.4

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Critical items which affect the number of splices ......................................................................... 5.14 Mean time between two splices ................................................................................................... 5.15 Field test ...................................................................................................................................... 5.16 Relationship between the productivity on winding machines and splices .................................... 5.17

Periodic yarn faults ............................................................................................................... 6.1 6.2

Influence of the yarn speed on the winding machine .............................................................. 6.2

6.3

Further reasons for periodic defects ......................................................................................... 6.2

6.4 6.4.1

Periodic fault registration with the PF ....................................................................................... 6.3 Setting for Periodic Faults (PF / Optional Q Data) ......................................................................... 6.3

6.5 6.5.1

The effect of periodic faults on the fabric appearance ............................................................ 6.6 Reasons and measures to minimize periodic mass variations ...................................................... 6.8

Quality parameters of a yarn................................................................................................. 7.1 7.1

Introduction .................................................................................................................................. 7.1

7.2 7.2.1 7.2.2 7.2.3 7.2.4 7.2.5 7.2.6

Yarn evenness ............................................................................................................................. 7.3 Definition of the coefficient of variation CV .................................................................................... 7.4 Reasons and effects of the yarn irregularity .................................................................................. 7.4 Deviation of the CV mean value of a group of clearers (CV–MV) ................................................. 7.5 Deviation of the CV of a single winding position (CV-SP) ............................................................. 7.6 Settings .......................................................................................................................................... 7.7 Display of the CV values ................................................................................................................ 7.9

7.3 7.3.1 7.3.2 7.3.3

Imperfections ............................................................................................................................. 7.10 Definition of imperfections ........................................................................................................... 7.11 Settings ........................................................................................................................................ 7.13 Display of the imperfection results ............................................................................................... 7.15

7.4 7.4.1 7.4.2 7.4.3 7.4.4

Class-Alarm ................................................................................................................................ 7.15 Definition of the classes ............................................................................................................... 7.16 Reasons and effects of the faults ................................................................................................ 7.17 Settings ........................................................................................................................................ 7.17 Display of the class alarms .......................................................................................................... 7.18

7.5 7.5.1 7.5.2

Tailored classes (Option Advanced Classes) ......................................................................... 7.19 Settings ........................................................................................................................................ 7.20 Display of the tailored classes ..................................................................................................... 7.21

7.6

Adjustment of the individual alarm possibilities .................................................................... 7.22

7.7 7.7.1 7.7.2 7.7.3 7.7.4 7.7.5 7.7.6 7.7.7 7.7.8

Hairiness..................................................................................................................................... 7.22 Principles of operation of the hairiness measuring systems........................................................ 7.22 Settings ........................................................................................................................................ 7.25 Display of the hairiness values .................................................................................................... 7.27 How do hairiness variations affect woven and knitted fabrics? ................................................... 7.28 Hairiness monitoring on the machine .......................................................................................... 7.28 On-line tests versus off-line tests ................................................................................................ 7.29 Basic hairiness differences between the different spinning methods .......................................... 7.30 Practical examples ...................................................................................................................... 7.31

7.8

Indication of ejected bobbins ................................................................................................... 7.33

7.9

Criteria to select the limits for quality characteristics ........................................................... 7.33

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7.9.1 7.9.2 7.9.3 7.9.4 7.9.5

Installation of a quality management system to eliminate outliers ............................................... 7.34 Tracing back outlier bobbins to the source .................................................................................. 7.36 Examples from the industry ......................................................................................................... 7.38 Recommendations for a sampling plan ....................................................................................... 7.39 Conclusion ................................................................................................................................... 7.41

7.10

Yarn evenness (CV), hairiness and imperfections and their effect on the fabric appearance ................................................................................................................................ 7.41 7.10.1 Reasons and measures to minimize random mass variations .................................................... 7.41 7.10.2 Reasons and measures to minimize imperfections ..................................................................... 7.43 7.10.3 Reasons and measures to minimize excessive hairiness and hairiness variations .................... 7.46

8

9

Foreign fibers ........................................................................................................................ 8.1 8.1

Introduction .................................................................................................................................. 8.1

8.2

Dense Area ................................................................................................................................... 8.3

8.3 8.3.1 8.3.2 8.3.3 8.3.4 8.3.5

Foreign fibers ............................................................................................................................... 8.5 Types of foreign material in cotton................................................................................................. 8.5 Degree of contamination of bales .................................................................................................. 8.8 Size and appearance of foreign matter in spinning mills ............................................................. 8.10 Frequency of foreign fibers in spinning mills ................................................................................ 8.11 Foreign fiber risk calculated for a spinning mill ............................................................................ 8.12

8.4

Classification matrix of foreign fibers with the USTER QUANTUM 3 ................................. 8.12

8.5 8.5.1 8.5.2 8.5.3 8.5.4

Clearing limits ............................................................................................................................ 8.13 General references for foreign fiber clearing ............................................................................... 8.14 Clearing limits for dark foreign fibers in light yarn ........................................................................ 8.14 Standard way of optimizing clearing limits: Manual clearing limits entry ..................................... 8.15 Setting a smart clearing limit for dark foreign matter (FD) ........................................................... 8.17

8.6 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.6.6 8.6.7

Foreign fibers and their effect on the various production processes ................................. 8.19 Methods to eliminate foreign material and frequency of foreign material .................................... 8.21 Effect of large foreign particles on the spinning process ............................................................. 8.24 Alarm options for frequent foreign fibers in yarns with clearers ................................................... 8.24 Limits of foreign fiber elimination ................................................................................................. 8.25 Process disturbances while beaming, weaving and knitting caused by foreign matter ............... 8.25 Recommended approach to eliminate foreign fibers ................................................................... 8.25 Field tests in China ...................................................................................................................... 8.26

8.7 8.7.1

Foreign fibers and their effect on the fabric appearance ...................................................... 8.30 Reasons and measures to minimize foreign fibers in yarns ........................................................ 8.33

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Vegetable Matter Clearing .................................................................................................... 9.1 9.1 9.1.1 9.1.2

Introduction .................................................................................................................................. 9.1 Vegetable matter ........................................................................................................................... 9.2 Distribution of vegetables and foreign fibers .................................................................................. 9.3

9.2

Dense area for vegetable matter (VEG) ..................................................................................... 9.3

9.3

Classification matrix of vegetable matters with the USTER QUANTUM 3 ........................... 9.6

9.4 9.4.1

Clearing limits .............................................................................................................................. 9.6 Setting a clearing limit for vegetable matter (VEG)........................................................................ 9.7

9.5

Vegetable matters and their effect on the fabric appearance ................................................. 9.9

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9.5.1 9.5.2

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Field test ........................................................................................................................................ 9.9 Reasons and measures to minimize vegetable matter in yarns .................................................. 9.11

® Detection of polypropylene fibers with USTER QUANTUM 3 ......................................... 10.1

10.1 10.1.1 10.1.2 10.1.3

Introduction ................................................................................................................................ 10.1 Configuration of a PP-clearer ...................................................................................................... 10.3 Frequency of PP fibers ................................................................................................................ 10.4 Application range of PP-clearing, ring-spun yarn ........................................................................ 10.6

10.2

Scatter plot ................................................................................................................................. 10.7

10.3 Clearing limits for polypropylene fibers .................................................................................. 10.9 10.3.1 Standard way of optimizing clearing limits: Manual clearing limits entry ..................................... 10.9 10.3.2 Setting a smart clearing limit for polypropylene fibers ............................................................... 10.10 10.4 Polypropylene fibers and their effect on the fabric appearance......................................... 10.12 10.4.1 Reasons and measures to minimize foreign fibers in yarns ...................................................... 10.13

11

® Various settings and applications of USTER QUANTUM 3 .............................................. 11.1

11.1 Comparison of different clearing limits and article settings ................................................. 11.1 11.1.1 Comparison of various clearing limits .......................................................................................... 11.1 11.1.2 Recreate or recall of the factory settings of the default articles ................................................... 11.3

12.

11.2 11.2.1 11.2.2 11.2.3

Display of Data and Alarms ...................................................................................................... 11.3 Display of Data and Alarms with the help of bar graphs .............................................................. 11.3 Display of Data and Alarms with the help of exception reports ................................................... 11.5 Display of yarn faults with the help of textile alarms .................................................................... 11.6

11.3 11.3.1 11.3.2 11.3.3

Collecting defects ........................................................................................................................ 11.8 Introduction .................................................................................................................................. 11.8 Event display by the red light at the sensor (iMH-LED) ............................................................... 11.8 Yarn fault cards............................................................................................................................ 11.9

11.4 11.4.1 11.4.2 11.4.3 11.4.4 11.4.5 11.4.6 11.4.7 11.4.8

Monitoring of winding functions............................................................................................ 11.11 ® Monitoring of the yarn t process with the USTER QUANTUM 3 ........................................ 11.14 Monitoring of the settings........................................................................................................... 11.14 Splice classification.................................................................................................................... 11.14 Yarn jump monitoring (JPM, JPA) ............................................................................................. 11.15 Drum signal monitoring (DSM) .................................................................................................. 11.16 Drum wrap monitoring (DWM, DWA) ........................................................................................ 11.16 Cut monitoring CTM .................................................................................................................. 11.17 Zero point monitoring ZPM ........................................................................................................ 11.17

Clearing of special yarns .................................................................................................... 12.1 12.1

Introduction to fancy yarns ...................................................................................................... 12.1

12.2

Clearing of fancy yarns ............................................................................................................. 12.1

12.3

Clearing of slub yarns ............................................................................................................... 12.3

12.4

Clearing of yarns with nep or loop effects .............................................................................. 12.5

12.5

Melange yarns ............................................................................................................................ 12.6

12.6

Core yarn .................................................................................................................................... 12.7

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The first hour at the new clearer system ........................................................................... 13.1 13.1

Introduction ................................................................................................................................ 13.1

13.2

Short description of the settings ............................................................................................. 13.1

Frequently asked questions ............................................................................................... 14.1 14.1 14.1.1 14.1.2 14.1.3 14.1.4 14.1.5

Product related questions ........................................................................................................ 14.1 ® What type of sensing principles does USTER QUANTUM 3 offer?........................................... 14.1 ® How does the USTER QUANTUM 3 differ from competing products? ...................................... 14.1 ® What are the main new functions of the USTER QUANTUM 3? ............................................... 14.2 ® What are the new quality parameters measured by the USTER QUANTUM 3? ....................... 14.3 ® What is the yarn count range of USTER QUANTUM 3 and which sensing method will fulfill the quality requirement? ...................................................................................................... 14.4 ® 14.1.6 What is new with the USTER QUANTUM 3 optical basic clearer? ............................................ 14.4 14.1.7 What is the difference to UQC2 Vegetable Filter?....................................................................... 14.4 ® 14.1.8 What is the advantage of the USTER QUANTUM 3 for core yarns? ......................................... 14.4 ® 14.1.9 What is the benefit of slub yarn setting in USTER QUANTUM 3? ............................................. 14.5 14.1.10 How is the PP performance of the new clearer? ......................................................................... 14.5 ® 14.1.11 How are the repair costs of USTER QUANTUM 3?................................................................... 14.5 14.1.12 What are the advantages from a maintenance point of view?..................................................... 14.5 ® 14.1.13 Can the USTER QUANTUM 3 is installed be winders of previous generations? ...................... 14.5 ® 14.1.14 Why does the USTER QUANTUM 3 have a bigger housing? ................................................... 14.6 14.1.15 What is the purpose of the arrow LEDs on the measuring head? ............................................... 14.6 14.2 14.2.1 14.2.2 14.2.3 14.2.4 14.2.5

Application related questions .................................................................................................. 14.6 What kind of yarn clearer do I need for my application? ............................................................. 14.6 How is it possible to simplify the definition of clearing limits? ...................................................... 14.6 How can one find the optimal setting for basic clearing? Is it the same as before? .................... 14.7 What is the best basic setting for my yarn? ................................................................................. 14.7 How can one find the optimum setting for good fabric appearance and for optimum productivity? ................................................................................................................................. 14.7 14.2.6 Which setting shall I use to make sure that no Classimat objectionable faults will remain? ....... 14.7 ® 14.2.7 What is the USTER QUANTUM 3 advantage with respect to compact yarns? ......................... 14.8 14.2.8 When should I use the vegetable clearing? ................................................................................. 14.8 14.2.9 Why cannot all vegetables using Vegetable Matter Clearing when they are not disturbing? ................................................................................................................................... 14.8 ® 14.2.10 We have an USTER QUANTUM clearer or other clearer generations - can we copy the setting because it was acceptable until now? ........................................................................ 14.9 14.2.11 What is different with the continuous count channel? Is the settings process easier? ................ 14.9 14.2.12 How can one set up the splice clearing curve? ........................................................................... 14.9 14.2.13 How can one find/identify rogue splicers? ................................................................................. 14.10 14.2.14 What FD setting should I keep for a cotton yarn? (In case of no specific requirement from the buyer) ......................................................................................................................................... 14.10 ® ® 14.2.15 USTER QUANTUM 3 has more than 40 classes, but in USTER QUANTUM 2, we ® only have 23 classes- What is the purpose of these additional classifications in USTER QUANTUM 3? ............................................................................................................................ 14.10 ® 14.2.16 USTER QUANTUM 3 has new sensor technology in basic and FM clearing – are the results comparable to the old classification? ............................................................................. 14.11 14.2.17 Can I use the QUANTUM 3 for wet splicer applications? .......................................................... 14.11 14.2.18 Is it possible to classify foreign fibers? ...................................................................................... 14.12 14.2.19 What are the experience values for cuts in ring spinning mills with foreign fiber clearers? ..... 14.12

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14.2.20 Can we compare the classification of C15 on C20 in USTER QUANTUM 3 ........................... 14.13 ® ® 14.2.21 Is the USTER QUANTUM 3 classification comparable to the USTER STATISTICS?........... 14.13

15

Technical specifications ..................................................................................................... 15.1 15.1 15.1.1 15.1.2 15.1.3 15.1.4

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Basics of USTER QUANTUM 3 ............................................................................................... 15.1 Architecture.................................................................................................................................. 15.1 Scope of application .................................................................................................................... 15.1 Scope of supply ........................................................................................................................... 15.1 Miscellaneous .............................................................................................................................. 15.2 ®

15.2 Structure of the USTER QUANTUM 3..................................................................................... 15.2 ® 15.2.1 Features of USTER QUANTUM 3 and options .......................................................................... 15.2 15.2.2 Features versus measuring head types ...................................................................................... 15.3 15.3

Comparison, capacitive versus optical measuring principle for basic clearing ................. 15.4

15.4

Winding machines ..................................................................................................................... 15.5

15.5

Count range of the USTER QUANTUM 3 ............................................................................... 15.5

15.6

Architecture, sensor principles and configuration ................................................................ 15.6

15.7

Elimination of disturbing yarn faults ....................................................................................... 15.7

15.8

Supervision of the machine operations .................................................................................. 15.8

15.9

Determination of quality characteristics ................................................................................. 15.9

15.10

Cut alarms, Quality alarms, Special Counters and Logbook .............................................. 15.11

15.11

Reports ..................................................................................................................................... 15.13

15.12

Clearing of various yarn types ............................................................................................... 15.15

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15.13 Recommendations how to use clearers ................................................................................ 15.16 15.13.1 Sensor systems versus end use of yarn .................................................................................... 15.16 15.13.2 Poor environmental conditions .................................................................................................. 15.18

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Appendix .............................................................................................................................. 16.1 16.1 Standard settings ...................................................................................................................... 16.1 16.1.1 Standard settings for the capacitive clearer – Capacitive Default ............................................... 16.1 16.1.2 Standard settings for the optical clearer – Optical Default .......................................................... 16.2 16.2

Abbreviations ............................................................................................................................. 16.3

16.3

Explanation of ................................................................................................................. 16.7

16.4 16.4.1 16.4.2 16.4.3 16.4.4

International Systems of units ............................................................................................... 16.11 International system ................................................................................................................... 16.11 'SI' system .................................................................................................................................. 16.11 Conversion table for yarn count systems................................................................................... 16.13 Conversion of English units into metric units ............................................................................. 16.14

16.5

Bibliography ............................................................................................................................. 16.15

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Foreword It is still not possible to produce a fault-free yarn in a spinning mill for various reasons. The drawing process is not a perfect process and can produce imperfections. Another source for irregularities in ring spinning is the availability of fiber flies in the air which are frequently spun into the yarn as well as accumulations of fiber fragments and dust at yarn guiding elements. In ring-spinning, all fiber and yarn guiding elements, ring travelers, pressure rollers, belts and spindles can contribute to yarn faults, particularly in case of defects. In OE-rotor spinning, the opening rollers and dirty rotor grooves are sources of yarn faults. In air-jet spinning the formation of faults depends on the quality of the raw material and the maintenance of the spinning devices. Natural fibers contain foreign matter which mostly cannot be eliminated completely and stickiness of cotton can contribute to the formation of thick and thin places. Therefore, one important rule of modern quality management cannot be implemented completely: “Preventive actions have to be taken rather than corrections afterwards!” As a result, an electronic monitoring system is required to eliminate disturbing faults in the yarn. In ring spinning the monitoring system is located on the winding machine. This system does not only eliminate disturbing faults in yarns, but also separates bobbins with high unevenness, high imperfections, high hairiness, etc. For all known spinning methods of today it is necessary to have a yarn monitoring system in the last production process of the spinning mill, which stops the production position if disturbing faults occur. The machine must automatically remove the faults and replace it by a splice or by a piecer. The first electronic yarn clearers were already installed on winders in 1960. At that time thick places could be removed only. In the last five decades, the electronic yarn clearer experienced an enormous development. In the meantime a monitoring system has been developed which cannot only remove faults but is also in a position to provide information on quality characteristics of the yarn. In the last years, new quality characteristics were added such as the hairiness of yarns and the quality of splices. As physical principle for electronic yarn clearing the capacitive and the optical principle have been established. Both principles have their strengths in specific applications. The experts of Uster Technologies will help the spinning mills to find the best solution. With the introduction of the electronic laboratory and on-line systems the yarn quality has improved steadily. Therefore, faults which were not removed ten years ago are found disturbing today. An example for this is the compact yarn. As a result, the requirements for yarn clearing are also increasing permanently. With the higher capability of the electronic yarn clearer, there is a need for more information to make best use of these systems. We hope that our customers can fully benefit from their investment into the USTER® QUANTUM 3 with this detailed knowhow.

R. Furter April 2011

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USTER® QUANTUM 3

1

Introduction

1

Introduction

1.1

Purpose of the application handbook

In order to be able to use the USTER® QUANTUM 3 with all its possibilities to its optimum, it is necessary to have a comprehensive knowledge about the clearer. It contains the experience we gained over the years and should fulfill the following purposes: •

Introduction to yarn clearing

for beginners and students

•

Instructions for optimum use

for the quality management of a spinning mill

•

Basis for the application training

for the instructor

In order to understand the explanations in this application handbook, it is advantageous, if: •

you have some knowledge about the textile production process, particularly the winding process

•

you are in a position to operate a winding machine with the USTER® QUANTUM 3 installed when going through the Application Handbook

Validity of this Application Handbook The explanations in this Application Handbook refer to the functions of the USTER® QUANTUM 3. They are subject to change without notice. Abbreviations and explanation of In the appendix of this book (section 16.2 and 16.3) a list of all the abbreviations and explanations of is given.

1.2

Yarn faults and yarn clearer

The principles of the spinning process for short- and long-staple yarns remained the same for many decades. Changes took place especially in the field of automation and production quantity per production hour in order to reach the highest production of yarn and with a good quality at the least expenses for personnel, capital and energy. For this, a significant technological progress in each process stage was essential. Despite this progress and many years of experience in spinning technology, it is still not possible to produce a fault-free yarn. Depending on the raw material and condition of the machinery, there are about 20 to 100 events over a length of 100 km yarn, which do not correspond to the desired appearance of yarns in fabrics. This means, that the yarn exhibits a disturbing yarn fault every 1 to 5 km. These kinds of yarn faults are places, which are too thick or too thin. Foreign fibers or contaminated fibers in the yarn are also counted as disturbing yarn faults. Fig. 1-1 shows the most important yarn fault categories which have to be eliminated on the winding machine in most of the cases.

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Introduction

Fig. 1-1

st

nd

rd

1 row: Disturbing thick places / 2 row: Vegetables / 3 row: Disturbing colored inorganic fibers / th 4 row: Disturbing white inorganic fibers (polypropylene)

Yarn faults cause disruptions in the subsequent process stages, which affect production and quality. Yarn faults, which are already processed into woven or knitted fabric, can only be removed at very high costs or not at all. Therefore, the yarn processing industry demands a fault-free yarn from the yarn producer. The spinner has to fulfill these demands; otherwise he cannot sell the yarn at reasonable prices. The spinner can fulfill these demands by a combination of two measures: 1.

Prevent the origin of yarn faults by adequate measures.

2.

Remove yarn faults by the aid of yarn clearers.

1.2

USTER® QUANTUM 3

Introduction

1

The measures to avoid the origin of yarn faults are numerous and start with the choice of the raw material, the maintenance of the machines up to the cleanliness in the spinning mill. Well educated, motivated personnel and an efficient quality management play also an important role. Yarn faults, which are still produced despite all measures, are removed according to the following principle:

Fig. 1-2

Principle of yarn clearing on the winding machine

1. During the winding process from bobbin to cone, the yarn is permanently monitored for yarn faults with an electronic device, the yarn clearer. 2. As soon as the yarn clearer detects a yarn fault, the yarn will be cut by the cutter if the fault exceeds the limits. For this purpose the winding process is interrupted. 3. The yarn fault is removed by the suction device of the winding machine. 4. Both ends, the upper yarn from the cone as well as the lower yarn from the bobbin, have to be ed again. The yarn t is done by splicing with a splicing device or knotting with a knotting device. The latter is only used very rarely for special yarns. A good splice should not be recognized by the human eye. Up to date yarn clearers also monitor the quality of the yarn t. 5. The winding process continues until the next fault occurs or the end of the bobbin is reached.

1.3

Short history of the USTER® yarn clearers

In 1960 Uster Technologies launched the first electronic yarn clearer, the USTER® SPECTOMATIC. With one single, central setting the threshold at which the cutter should be activated could be determined. Once on the market, the demands for the yarn clearer rose steadily. Since then, Uster Technologies could always fulfill the demands of the customers to their full satisfaction with innovative clearer models.

USTER® QUANTUM 3

1.3

1

Introduction

Fig. 1-3 shows the improvements and features since 1960 up to the eighth generation of the USTER® QUANTUM 3 of today for winding machines.

Fig. 1-3

Uster clearer generations and their additional functions for winding machines

The numerous functions of the USTER® QUANTUM 3 for a comprehensive yarn control can be summed up as follows: •

Monitoring and elimination of disturbing yarn faults

•

Monitoring and controlling of machine functions

•

Determination of quality parameters of the yarn

•

Triggering of alarms if outlier bobbins occur

•

Visualization of data on the display, for reports, information systems and for the subsequent process stages

1.4

USTER® QUANTUM 3

Introduction

1

In order to define and control all these functions, various settings to fulfill all the requirements in the textile industry can be carried out at the USTER® QUANTUM 3. This stands in contrast to one single setting of the first clearer generation.

1.4

Origin of seldom-occurring yarn faults

1.4.1 Separation of frequent and seldom-occurring yarn faults During the spinning process, a card sliver with about 20'000 to 40'000 fibers in the cross-section is drawn to a yarn with about 40 to 1000 fibers in the cross-section. During the spinning process it is not possible to keep the number of fibers in the cross-section constant at every moment. This leads to random variations of the mass. Only spinning mills with a permanent improvement process are able to keep these random variations within close limits. These variations are measured by the evenness tester in the laboratory. They are a measure for the unevenness of the yarn and are called imperfections. They occur so frequently that they are not eliminated from the yarn (Fig. 1-4). Their number of imperfections is generally given per 1000 m of yarn. In contrast to the frequent yarn faults, there are also the seldom-occurring yarn faults. The difference between the frequent yarn faults and the seldom-occurring yarn faults is mainly given by the larger mass or diameter deviation. As these faults occur only seldom, their number is expressed per 100'000 m. These faults are monitored and classified by the USTER® CLASSIMAT or by the clearer installation on the machine.

Fig. 1-4

Frequent yarn faults and seldom-occurring yarn faults. The deviations in percent are either mass or diameter related, depending on the type of sensor.

USTER® QUANTUM 3

1.5

1

Introduction

The average mass increase for thick places has to exceed +75% for faults below 2 cm, 45% for faults below 4 cm length and +30% for faults longer than 4 cm to be counted by the classifying system of the USTER® QUANTUM CLEARER. In the area of thin places the average mass of a fault has to drop at least 20% to be counted.

Fig. 1-5

Classification matrix for disturbing thick and thin places

1.4.2 Distinction between frequent and seldom-occurring yarn faults Fig. 1-6 shows the position of the frequent yarn faults (imperfections, green area in Fig. 1-6) in comparison to the position of the seldom-occurring yarn faults in the classification matrix. It is obvious, that both types of yarn faults differ from each other clearly by their. In addition, the areas of the clearer settings N, S, L, T, C and CCm are indicated. This shows where the settings are effective. N = neps, S = short thick places, L = long thick places, T = thin places, C = count deviations in positive direction, CCm = count deviation in minus direction.

Fig. 1-6

1.6

Positions of the frequent versus the seldom-occurring yarn faults

USTER® QUANTUM 3

1

Introduction

1.5

Classification of seldom-occurring thick and thin places

Classifications are used in spinning mills either as on-line monitoring system as a feature of the clearing system on automatic winding machines or as an analyzing instrument on manual winding machines in textile laboratories, and they play a very important role to analyze seldom-occurring yarn faults. Fig. 1-7 shows the classification matrix of this analyzing system with a few examples of seldomoccurring yarn faults for the thick place classes A1 to D4 which are assigned by the system to the respective classes.

Fig. 1-7

®

Classes of the USTER CLASSIMAT QUANTUM system. The new classes are not shown in this figure

It is obvious that the appearance of seldom-occurring faults in a fabric depends on various items: •

The cross-section of the fault compared to the mean value

•

The length of the fault

•

The count of the yarn

•

The yarn density in the fabric

•

The type of fabric (weaving or knitting)

USTER® QUANTUM 3

1.7

1

Introduction

1.6

Allocation of seldom-occurring yarn faults to the Classimat matrix

A basic rule in quality management is a preventive maintenance rather than corrections afterwards. Unfortunately, this is not yet possible with the technology of today. Textile specialists in spinning mills who have to conquer disturbing yarn faults have to find the origin of such yarn faults. Table 1 shows a selection of sources which produce seldom-occurring faults in the respective categories. It is a collection of reasons over many years why such events happened. The classes A0 to I2 correspond to the matrix, Fig. 1-5. Classes

Possible reason of faults

A (Thick place)

Comments

A0

Extended class, mainly used for ply yarn and compact yarn

A1

Bad condition of carding, blow room, trash in yarn

A2

Bad condition of carding, blow room, trash in yarn

A3

Neps, fluff, foreign matters, dirty drafting zone

A4

Ring front zone dirty, fly in trumpet

B0


B1

Fibers damage in process, spindle without aprons

B2

Fibers damage in process, spindle without aprons

B3

Fluff in travelers, unsuitable travelers, bad piecing

B4

Slub from ring spinning department

C0


C1

Bad piecing in cans, sliver entanglements

C2

Bad piecing in cans, sliver entanglements

C3

Piecing, ring spinning

(Unacceptable faults)

C4

Floating fibers, fly, slub


D0


D1

Floating fibers

D2

Gauge problem of roving frame, spacer problem


D3

Fluff in ring spinning or roving


D4

Fluff in ring spinning or roving


E (Thick place)

E

Double yarn, count variation

(Spinners double)

F (Thick place)

F

Bad piecing in ring yarns, roving & back process

(Long thick places)

G (Thick place)

G

Bad piecing in ring, roving & back process etc.

(Long thick places)

H (Thin place)

H1

Mostly eccentric bobbins on roving & ring frames, eccentric spindles, drawing problems

(Thin places)

H2

Poor handling of material during processes

(Thin places)

I1

This type of faults is mostly produced by separation of parts of sliver or roving prior to spinning

(Long thin places)

I2

This type of faults is mostly produced by separation of parts of sliver or roving prior to spinning

(Long thin places)

B (Thick place)

C (Thick place)

D (Thick place)

I (Thin place)

Table 1

1.8

(Short thick places)





Classimat defects / Classification and sources of origin. New classes are not mentioned in Table 1.

USTER® QUANTUM 3

Introduction

1

Disturbing yarn faults caused by raw material and card These faults depend on the quality of the raw material. For natural fibers, they depend mainly on the physical properties such as fiber fineness, length and short fiber content. For synthetic fibers, the faults depend mainly on the disentanglement of single fibers. Insufficient disentanglement can lead to felted single fibers, which might be caused by softeners, oil additives, lubricants or climatic conditions. Disturbing yarn faults caused by processes prior to spinning These faults are characterized by extreme diameter variations or poor friction of the fibers. Often, it is a matter of fiber packages, which are not caught in the draw-box of prior processes and were not drawn apart. Therefore, they show a big increase of the mass or diameter in the yarn.

Disturbing yarn faults caused in spinning Most disturbing yarn faults are caused by spun-in fly in the area of the ring spinning machine and by fiber residues, which cling to the draw-box or other parts of the spinning machine and which are swept away from time to time and are spun into the yarn. Furthermore, it is possible that different setting possibilities of the ring spinning machine, as e.g. draft or distance settings of the draw-box, have an influence on the number of seldom-occurring yarn faults. Thick places in a woven fabric are shown in Fig. 1-8 to Fig. 1-9. Here we can see a spun-in fly failure. This refers to free fibers which fall into the drafting elements or onto the roving which is being fed into the drawing unit of the ring spinning machine and are then twisted into the yarn along their entire length.

Fig. 1-8

Flying fibers which fall onto the roving or into the drafting elements and are then twisted into the yarn

USTER® QUANTUM 3

Fig. 1-9

Thick place in woven fabric as a result of a spun-in fly

1.9

1

Introduction

As most of these yarn faults can lead to problems in the subsequent processes or are disturbing in the end product, they must be removed from the yarn and replaced by a splice. The art of yarn clearing consists of cutting out the most disturbing faults without influencing the efficiency of the machine too much. Therefore, yarn clearing is always a compromise.

Foreign fibers Foreign fibers in the yarn belong also to the group of seldom-occurring yarn faults. The cause for foreign fibers are contaminations, which get crushed in the spinning process, especially by the card, and are noticed as foreign fibers in the yarn at the end of the spinning process. Further explanations concerning this subject can be found in chapter 8, "Foreign fibers", of this Application Handbook.

Fig. 1-10

Fig. 1-11

1.10

Classification matrix for foreign fibers and vegetables

Foreign fiber in a yarn

Fig. 1-12

Vegetable in a yarn

USTER® QUANTUM 3

Introduction

1.7

1

Structure of the USTER® QUANTUM 3

The USTER® QUANTUM 3 is the successor of the USTER® QUANTUM 2. This new clearer generation is focused on simplifying the complexities of yarn clearing and thereby enable the to easily and fully exploit all clearer capabilities and to optimize production costs every day. The USTER® QUANTUM 3 interprets and displays the yarn characteristics within minutes and proposes a starting point for clearing limits with a cut forecast by pressing a single button. One of the key highlights is the integration of the well-known USTER® knowhow in the system on the winder. Another exciting new innovation is a completely new foreign fiber clearing technology with vegetable clearing which is able to detect all colors and separates foreign matter into two separate pools: foreign fibers and vegetables. This separation improves the foreign fiber clearing efficiency significantly by reducing cuts for the same quality or gets a better quality for the same cuts.

Fig. 1-13

®

New features of USTER QUANTUM 3

USTER® QUANTUM 3

1.11

1

Introduction

1.7.1 Features of USTER® QUANTUM 3 and options Table 1-2 shows the individual features of the options. OPTIONS Basic clearing

Foreign matter

FEATURES

COMMENTS

Yarn Body (N, S, L, T, CC)

Visualization of the yarn characteristics

Smart limits (N, S, L, T, CC)

A proposed starting point for clearing limits

Scatter plot (N, S, L, T, C, CC, J)

Visualization of the thick and thin places, count deviations and splices.

N, S, L, T

Elimination of the disturbing thick and thin places

C, CC

Count deviation clearing and monitoring

Jp, Jm

Splice Clearing

Cut forecast

A forecast of cut numbers per 100 km

Technical alarms

Alert for technical problems

Textile alarms

Alert for textile problems

Dense Area (FD, VEG)

Identification of range where foreign fibers are located

Smart limit (FD)

A proposed starting point for foreign fiber clearing limits

Vegetable Clearing

Scatter plot (FD)

Visualization of dark foreign fibers

(Option)

Dark foreign matter (FD)

Elimination of dark foreign fibers

On-line foreign matter classification

Classification of foreign fibers

Identification of vegetables

Separation of vegetable matter

On-line vegetable classification

Classification of vegetable matter

Polypropylene fibers (Option)

Smart limit (PP)

A proposed starting point for polypropylene clearing limit

Scatter plot (PP)

Visualization of polypropylene fibers

Q-Data (Option)

Evenness (CV)

Determination of the yarn evenness

Imperfections

Determination of the frequent thick places, thin places and neps

Basic on-line classification (NSLT, FD, J and VEG)

Classification of disturbing thick and thin places, foreign fibers, splices and vegetables

Class alarms

Triggering of alarm if the number of disturbing faults has exceed the selected number of faults

Periodic Faults (PF)

Detection of periodic faults

Absolute hairiness measurement

Determination of the hairiness value

Exception spindle detection

Recognition of spindles with excessive hairiness

Expert

Access to the data output for Expert System and centralized data collection and reporting

Extended Classes

Classification of additional classes in NSLT, F, VEG

Tailored classes

Classes can be selected by customers

Software pack

Software pack consists of Hairiness, Advanced Classification and Expert

Hairiness (Option) Expert (Option) Advanced Classification (Option) Lab On-line (Option) Table 1-2

1.12

Features of Basic Clearing and options

USTER® QUANTUM 3

1

Introduction

1.7.2 Features versus measuring head types Table 1-3 below describes what type of USTER® QUANTUM 3 sensor for each measuring head is appropriate for which kind of application. ®

USTER QUANTUM 3 SENSORS

FEATURES

MEASURING HEAD TYPES

Capacitive C15

Capacitive Capacitive C20 C15 F30

Capacitive C20 F30

Optical O30

Optical O30 F30

BASIC

X

X

X

X

X

X

FOREIGN MATTER (Option)

---

---

X

X

---

X

VEGETABLE (Option)

---

---

X

X

---

---

POLYPROPYLENE (Option)

---

---

O*

O*

---

---

Q-DATA (Option)

O

O

X

X

O

X

HAIRINESS (Option)

---

---

O

O

---

O

USTER QUANTUM EXPERT 3

O

O

O

O

O

O

ADVANCED CLASSIFICATION (Option)

O

O

O

O

O

O

LAB ONLINE (Option)

---

---

O

O

---

O

®

Table 1-3

®

The USTER QUANTUM 3 sensors and options

Key: X

This feature is included in this version of the sensor

O

Product Option Key (POK) is needed to have access to the feature mentioned in the header of this column

O*

Hardware upgrade required in the Central Clearing Unit 6 (CCU6) to have access to the feature

---

Not available with this iMH type

USTER® QUANTUM 3

1.13

1

1.14

Introduction

USTER® QUANTUM 3

Basics of yarn measurements and yarn clearing

2

Basics of yarn measurement and yarn clearing

2.1

Purpose of this chapter

2

This chapter explains the sensor technology and its characteristics, which is used in the USTER® QUANTUM 3. The basics of the yarn signal analysis and the yarn clearing are illustrated in the following figures and should the understanding of the additional chapters of this application handbook.

2.2

Monitoring of thick places

In order to be able to monitor and to evaluate thick and thin places as well as deviations from the nominal yarn count, the thickness of the yarn must be converted into a proportional electrical voltage. The course of the voltage is called yarn signal. Yarn piece with thick place

Electrical yarn signal +V 0 -V

Fig. 2-1

Yarn signal, result of a thick place

In the USTER® QUANTUM 3, the conversion is carried out either with the sensor of the capacitive measuring principle or with the sensor of the optical measuring principle. The sensor is part of the intelligent measuring head iMH which also consists of the electronic system to convert mass or diameter variations into a proportional electric signal.

There are very high demands for both measuring principles regarding the resolution and precision of the results. The sensor must be able to monitor a yarn which runs with up to 120 km/h through the sensor and to detect even very short faults. In order to achieve this, the yarn signal is determined every 2 mm.

USTER® QUANTUM 3

2.1

2


2.2.1

The capacitive measuring principle 4 1

5

3

Fig. 2-2

2

Capacitive sensor

The electrical measuring condenser (1) forms the sensor for the capacitive monitoring of the yarn mass. This is done by two parallel metal plates, the electrodes. In the space in between (2), the two electrodes build an electrical field when putting on an electrical alternating voltage (3). If a yarn (4) is brought into this field, the capacitance of the measuring condenser changes. From this change, an electrical signal, the yarn signal (5), is derived. The change of the capacitance depends, besides of the mass of the yarn and of the dielectric constant of the fiber material used and the moisture content of the yarn. With the capacitive measuring principle, the yarn signal corresponds to the yarn mass, which is located in the measuring field. Changes of the yarn mass cause a proportional change of the yarn signal.

2.2.2

The optical measuring principle 4 2 1

3

5

Fig. 2-3

Optical sensor

The infrared light source (1) and the photocell (3) represent the sensor for the optical monitoring of the yarn thickness. The infrared light is scattered by a diffusor (2) in the measuring zone and reaches the photocell (3). The photocell generates an electric signal, which is proportional to the light intensity. If a yarn (4) is brought into the measuring zone, parts of the light will be absorbed by the yarn. The amount of light, which hits the photocell, is smaller. From this change, an electrical signal, the yarn signal (5), is derived.

2.2

USTER® QUANTUM 3


2

With the optical measuring principle the yarn signal corresponds to the diameter of the usually circular shape of the yarn, which is located inside the measuring field. Changes of the yarn diameter cause a proportional change of the yarn signal.

2.2.3

Yarn signal definitions

Independent of the used measuring principle, the evaluation is carried out on the basis of the relative yarn signal change in contrast to the base value. The base value corresponds to the count of the wound yarn. + 200% + 150% + 100% + 50% 0% - 50% - 100%

1

Fig. 2-4

2

3

4

5

Definition of the yarn signal

1. No yarn in the measuring field: in this state, the yarn signal is defined as –100%. 2. A yarn of a certain count is inserted into the measuring field. The yarn signal changes from –100% to 0%. The change of 100% corresponds to the yarn count. 3. The yarn is moved in the measuring field. The yarn signal corresponds to the yarn evenness. The mean value of the evenness variation is defined as 0%. 0% is the base value for the deviations of a positive thick place and a negative thin place. 4. Thick place in the measuring field: the deviation is measured in % to the base value. In the example (Fig. 2-4), the deviation is +130%. If the signal exceeds the clearing limit set, the fault will be cut. 5. As soon as the yarn leaves the measuring field, the yarn signal drops to –100%. The definitions are valid for both measuring principles. The change in percent refers to the crosssection in case of the capacitive measuring principle and the diameter in the case of the optical measuring principle. This means that an increase or decrease of the yarn mass produces different deviations (%) of the yarn signal depending on the physical principle of the sensor. Table 2-1 shows the relationship between the cross-section and the diameter changes.

USTER® QUANTUM 3

2.3

2


Yarn Regular yarn

Thick places with double cross-section

Thin place with half of the cross-section Table 2-1

Yarn signal (capacitive)

Yarn signal (optical)

0% base value

0% base value

Increase of cross-section: +100% Increase of diameter: +41%

Decrease of cross-section: -50%

Decrease of diameter: -29%

Relationship between the cross-section and diameter

The higher resolution of the capacitive sensor is particularly helpful in areas where already small deviations from the nominal value can be disturbing for the human eye (e.g. in compact spinning as a result of the missing hairiness). This table indicates that the used measuring principle must always be known. Otherwise, it can lead to misinterpretation. Fig. 2-5 shows the relationship between the cross-section and the diameter changes.

Fig. 2-5

2.4

Optical and capacitive measuring systems

USTER® QUANTUM 3

2


Example: The mass of a thick place in the measuring zone increases by +300% compared to the mean of the yarn. How much is the rise of the signal of the optical system? According to Fig. 2-5 the optical signal (proportional to the diameter) increases by +100%. Remarks: This is valid for yarn faults with equal density of the fibers esp. long, well twisted yarn faults. For short and fluffy yarn faults the diameter deviations is more or less the same as the mass deviation. 2.2.4

Characteristics of the two measuring principles

Why are there two different measuring principles for yarn clearing? The requirements in the textile industry depend on the textile fibers and the end-use. The experts of Uster Technologies can the s to select the best clearer. The following Table 2-2 shows the most important differences of their properties. Characteristics

capacitive principle

optical principle

Proportionality

Corresponds to the mass/crosssection of the yarn or the number of fibers in the measuring field

Corresponds to the diameter of the yarn

Measuring field length

The yarn signal is the mean value of The yarn signal is the mean valthe piece of yarn which is located in ue of the piece of yarn which is the measuring field. Length: 4 mm located in the measuring field. Length: 3 mm

Evaluation of the yarn fault Normal yarn fault

The fault is evaluated with the full increase of the cross-section in percent.

The fault is evaluated with the full increase of the diameter in percent.

Voluminous, visually large appearing As the number of additional fibers is The very voluminous yarn fault yarn fault not extremely high, this yarn fault is absorbs a lot of additional light. recognized as relatively insignificant. Therefore, the fault is considered as significant.

Short yarn faults, length: 3 mm

The fault is evaluated with the full increase of mass.

The fault is evaluated with the full increase of the diameter.

Very compact yarn fault

The fault is evaluated with the full increase of the cross-section. Due to the higher number of fibers in the cross-section, the thick place can absorb more dye stuff and appears darker in the end product.

This compact yarn fault absorbs only a small amount of light. The increase of the diameter is considered as too insignificant in comparison to the cross-section.

The distance between two white lines is 1 cm. Table 2-2

Properties of the measuring principles

USTER® QUANTUM 3

2.5

2


2.2.5

Environmental influences on yarn measurement and yarn clearing

Environmental influences and material characteristics have different effects on both measuring principles. Therefore, for certain applications one measuring principle may be more appropriate than the other one. Table 2-3 shows the most important influences on the yarn measurement and the yarn clearing with both measuring principles, respectively. Influence

Capacitive measuring principle

Optical measuring principle

Fiber material

Most fiber materials can be measured with both measuring principles. Yarns, which contain electrically conductive Can be measured without limitations. fibers or are treated with electrically conductive spinning additives, cannot be measured.

Colored yarns

No or only little influence

Color differences within the bobbins can lead to different sensitivities (see 2.4.2, Calibration process on a running yarn), but can also serve for the monitoring of color differences. Dark yarns require in most cases other settings than light yarns.

Fiber blends

No or only little influence Wrong fiber blends can be monitored within certain fiber differences with the C- and CCchannel (see chapter "Count variations").

Wax

If the wax device is located below the yarn clearer, there is the tendency of a dirty measuring field. The selection of a suitable wax can keep the contamination within acceptable limits. The capacitive measuring field is less affected by wax.

Contamination

Usually, the measuring field is cleaned to a great extent by the yarn hairiness. The

change of the yarn signal caused by the contamination is compensated within certain limits. If the contamination gets too high, a technical alarm is triggered. Atmospheric humidity

Normal variations in the humidity have no influence.

Yarn moisture

Normal variations have no influence as long as the yarn structure doesn’t change. Non-homogenous yarn humidity can lead to unjustified cuts.

Very dry yarns exhibit a higher hairiness. This suggests a larger diameter and can lead to unjustified cuts.

If wet splicing is used, Uster Technologies must be consulted.

Table 2-3

2.6

Environmental influences and their effects

USTER® QUANTUM 3


2

Moisture of the yarn / Capacitive measuring system One characteristic of textile material is the ability to absorb moisture. The moisture that can be absorbed depends on the relative humidity of the environment. Cotton contains about: •

6,6 percent by weight of moisture at a relative humidity of 50%

•


•


Besides the yarn, the capacitive measuring principle measures also the moisture of the yarn. Therefore, and as the deviations of the yarn fault are always referred the mean value of the yarn signal, a homogenous distribution of the humidity along the yarn should be striven for. Large variations in the distribution of the moisture can lead to unjustified cuts. In order to reach a high and constant production and quality, a stable climate and the avoidance of fast changing variations of the relative humidity, respectively, are needed. Blended yarns made out of various colored fibers (melange) / Optical measuring system In a blend of various colored fibers with high light reflection differences (e.g. black/white), disturbances in the blend can lead to clearer cuts. This characteristics, however, can be used with the intention to control the fiber blend in such yarns.

2.2.6

Selection of the suitable measuring principle

Yarn clearing is the final control in a spinning mill. In order to produce the best possible yarn quality, all capabilities of a yarn clearer system should to be used. This also includes the selection of the most suitable measuring principle. The previous explanations and the chapter "Technical Specifications", Chapter 15 should help to make the best choice. If you are not completely sure, please do not hesitate to a representative of Uster Technologies, who will be glad to assist you.

2.3

Monitoring of foreign fibers in the yarn

The demands of the world market on the yarn quality have risen steadily over the last couple of years, also in regard of foreign fiber faults. Today, it is expected from a yarn clearer that it detects a single colored fiber in the yarn.

USTER® QUANTUM 3

2.7

2


2.3.1

Characteristics of the sensor for foreign fibers

Intensity In contrast to the human eye, the foreign fiber sensor measures the contrast between the yarn itself and the foreign fiber. The intensity of the contrast does not only depend on the color of the foreign fiber, but also on its surface structure. The wavelength of the light sources which are used in the sensor also plays an important role. The signal which is generated by the foreign fiber sensor is defined as the intensity of the foreign fiber. The intensity of the foreign fiber – or, to be more precise, the change of the light reflection – is given in % foreign fiber signal. For dark foreign fibers in a white yarn: 0% = Reflection of the yarn without foreign fiber 100% = Reflection of a completely black foreign fiber

The following Table 2-4 shows some foreign fiber faults as seen by the human eye and by the sensor: Human eye

Reflection sensor

Intensity 16%

16%

9%

32%

7%

Table 2-4

Evaluation of foreign fibers

Length The duration of the signal corresponds to the foreign fiber length. The length is given in mm. Detailed explanations for the monitoring of foreign fibers can be found in chapter 8 "Foreign fibers". With the multicolor light source of the USTER® QUANTUM 3 it is possible to detect foreign fibers of all colors.

2.8

USTER® QUANTUM 3


2.4

2

Communication of the yarn clearer with the winding machine

In order to recognize the status of the winding machine, an exchange of information is needed between the clearer and the winder.

2.4.1

Zero point adjustment

If there is no yarn in the measuring field, the yarn signal must show –100%. Dirt and changes inside the measuring field can cause that the yarn signal is not –100% when yarn is removed from the measuring field. With the zero point adjustment, these deviations are compensated and the yarn signal is set on –100% again. The zero point adjustment is carried out before the splicing process, i.e. when the measuring field is empty. If the control range is not sufficient for the zero point adjustment to set the yarn signal to -100% (measuring field too dirty or blocked with fly), a technical alarm for the respective sensor is triggered.

2.4.2

Calibration process on a running yarn

As already explained, thick and thin places in a yarn are ed as deviation from the nominal yarn value in percent. Foreign fibers are ed as changes of the light reflection in percent. In order to make this possible, the sensor has to collect know-how on the yarn first, i.e. the sensor needs a startup process on the running yarn. The determination of the nominal yarn count, in the following called the calibration value, is carried out automatically during the start-up of a new article and is adjusted continuously at every start of a winding position. The V-value * regulates the amplification of the yarn signal, so that the nominal yarn count represents 0%. There are separate V-values for the thick and thin place detection as well as for the foreign fiber detection.

Fig. 2-6

Calibration process. Course of the calibration process for thick and thin place clearing.

* V = Analog Digital Mean Value, represents the yarn mean value

USTER® QUANTUM 3

2.9

2


This yarn mean value is the mean value of all clearers of a group. With this value it is possible to calculate percentage deviations between two or several yarns. The V value consists not only of the yarn count, but also of yarn properties such as fiber type, moisture, color, etc. The number of the start-ups per group and winding position during production changes (red rectangle) until it reaches the value of 200, and because the calculated mean value is statistically stable, after 200 the count will not change anymore.

Fig. 2-7

Deviations to the nominal value

Storing of the calibration values for the optical sensor When processing colored yarns with the optical sensor, color sensitivity differences between the sensors can lead to start-up problems and to changes in the clearing sensitivity. In order to avoid this problem, it can be switched to "O-Single Adj" by means of the article. This has the effect that the calibration value is calculated for each sensor individually and not per group. Calibration procedure for foreign fiber clearing Each sensor calculates its own individual foreign fiber calibration. The fine adjustment of the calibration value is also carried out for each single sensor. The principle procedure is the same as for thick places.

2.10

USTER® QUANTUM 3


2.4.3

2

Yarn detector

The yarn detector monitors the status of the yarn in the measuring field: yarn not available, yarn not moving, yarn moving. The yarn detector controls some functions of the machine. Static yarn detector SYD The static yarn detector detects, if there is yarn in the measuring field or not: No yarn in the measuring field

SYD = turned off

Yarn in the measuring field

SYD = turned on

If the SYD is turned off, the DYD cannot be turned on.

Yarn mean value

0%

threshold No yarn

-100%

on SYD Static yarn detector off

Fig. 2-8

Status of the static yarn detector SYD

The SYD is switched on as soon as the threshold is reached.

Dynamic yarn detector DYD The dynamic yarn detector DYD determines if the yarn in the measuring field is running or not. Yarn in the measuring field is stopped Yarn in the measuring field runs

DYD = off DYD = on

•

If the DYD is turned off, the clearing channels are blocked.

•

If the DYD is turned off, the winding position will not / is stopped.

The DYD is turned on by the yarn signal change, which is caused by the unevenness of the running yarn. The sensitivity and the timing for turning on and off are set. For exceptional cases (processing of special yarns) a manual adjustment of the yarn detector settings according to the sensor type as well as to the winding machine type is available.

USTER® QUANTUM 3

2.11

2


Yarn detector test function The status of the static and dynamic yarn detector can be displayed at the iMH-LED (iMH = intelligent measuring head / LED = light emitting diode), Fig. 2-9: service / special functions / iMH LED display. SYD/DYD, press OK. No yarn: off SYD:  DYD: 

Fig. 2-9

Setting of the iMH-LED display function

Fig. 2-10

Display of the status of the yarn detector at the iMH-LED

Use this test mode, if there are any problems with the yarn detector, i.e. if there are any winding positions which do not run or do not stop when the yarn breaks.

2.12

USTER® QUANTUM 3


2.4.4

2

Winding speed

Fault length Besides the mass or diameter variation, the fault length is also decisive for the evaluation of a yarn fault. The fault length is determined by the time, during which the fault runs through the measuring field. Again, this time depends on the yarn speed and the winding speed, respectively. Wound length The clearer also determines the length of the wound yarn. The wound length is calculated from the winding speed and the time during which the dynamic yarn detector is turned on.

Winding speed In order to calculate the fault length and the wound yarn length correctly, the clearer needs the information about the winding speed.

2 3 1

Fig. 2-11

Winding machine / Drum drive with drum impulse sensor

The winding speed and the yarn speed, respectively, are defined by the friction drive between the guide drum (1) and the cross-wound cone (2). The sensor (3) delivers a certain number of drum impulses per rotation of the guide drum. These impulses are evaluated by the yarn clearer to measure the winding speed. Older or more simple winding machines do not have a drum sensor. For clearer installations on such machines, the winding speed must be set at the control unit.

USTER® QUANTUM 3

2.13

2


The winding speed which is given by the drum impulse or the setting at the control unit does not always correspond to the effective yarn speed. The yarn speed is additionally influenced by the following parameters: •

Yarn displacement Depending on the subsequent processes of the yarn, cones with various conical shapes are used. With a cone of e.g. 9°15", the speed variation can be significant.

•

Slippage If the guide drum turns faster than the cone, slippage occurs. Thus, the yarn runs at lower speed through the measuring field. A yarn fault appears longer than it is in reality. Incorrect cuts during start-up or during winding and incorrectly inspected yarn ts (splices/knots) can be the consequences in the extreme case. Slippage occurs at a fast start-up of the guide drum or when the processed material exhibits a low static friction. In order to avoid slippage it is necessary to set the start-up curve so that the crosswound cone starts synchronously with the guide drum. This is of special importance for the production of cross-wound cones with a large diameter.

•

Ribbon winding If the diameter of the cross-wound cone stands in a even number ratio to the diameter of the guide drum, ribbon winding can occur. The anti-patterning device, which is generated by the variation of the drum speed, avoids this. Variations of the winding speed are the result. These variations are ed on winding machines with the drum impulse sensor and thus taken into by the yarn clearer. The desired slight slippage is not taken into .

2.14

USTER® QUANTUM 3

Disturbing thick and thin places

3


3.1

Introduction

3

This chapter will explain the classification and monitoring of disturbing thick and thin places. Staple fiber yarns always have a specific unevenness. The reasons for their origin are diverse. At a certain size (mass or diameter and length) this unevenness will be disturbing in the yarn. Electronic yarn clearing is a process in which disturbing yarn faults are detected and eliminated. In ring spinning, yarn clearing is carried out on winding machines with a winding speed of up to 2500 m/min. Yarn monitoring and yarn clearing is based on the mean value of the yarn. This yarn value is determined by the measuring head itself. This is valid for the capacitive as well as for the optical measuring head. During the spinning process, it is not possible to keep the number of fibers in the cross-section constant at every moment. This leads to random variations of the mass or the diameter. Only those spinning mills with a permanent improvement process are able to keep these random variations within close limits.

3.2

Definition of the yarn body

The USTER® QUANTUM 3 interprets and displays the yarn characteristics with the help of the yarn body. The powerful capacitive and optical sensors of the USTER® QUANTUM 3 can determine the full yarn body including very short and fine defects. The clearer analyzes the yarn fault distribution and displays the yarn profile, which is called “yarn body”, in a few seconds or minutes. The yarn body is simply the normal yarn with its set of expected natural variations and represents the nominal yarn with its tolerable, frequent yarn faults. Yarn body is a new yarn characteristic, and we know from the experience so far that the yarn body changes according to the raw material and the spinning process. By analyzing the shape of the yarn bodies out of different raw material varieties and process changes, we can discover patterns and build up references. Based on the references, the operator can identify changes. The yarn body becomes always wider in the direction of the short yarn variations, e.g. short faults occur more frequently. On the contrary, the yarn body becomes smaller in the direction of the long yarn variations. The yarn body is a significant tool to help finding the optimum clearing limits, not only for thick places (NSL) and thin places (T), but also yarn count deviations (later called C and CC faults).

The yarn body is composed of two parts: •

Dark green area representing the real yarn body.

•

Light green area representing yarn body variations.

USTER® QUANTUM 3

3.1

3


In Fig. 3-1, the dark green area represents the yarn body and the light green area the yarn body variations, and this figure shows that the yarn body becomes wider in the direction of the short yarn faults. The short yarn faults with a significant mass or diameter deviation from the mean value (zero line) are considered less disturbing by the human eye compared with long yarn faults with little deviation. Short faults also occur more often. The number of clearer cuts increases considerably if the clearing limit is set in the green area. The vertical scale represents the yarn mass or diameter increase and decrease, and the horizontal axis represents the faults length in cm. In Fig. 3-1, besides two green areas, there are also green dots which represent remaining events in the yarn and red dots which represent cut yarn faults (disturbing events). The number of expected fault cuts per 100 km together with setting limits are shown with red color (in Fig. 3-1, top right corner, 311,6 km of yarn was wound and the expected fault cuts for thick places calculated per 100 km is 96,0 cuts). The cut ratio will be statistically representative after running 100 km of yarn. At a winding speed of 1500 m/min and 60 winding positions per machine, it lasts approximately 1 minute.

Area of the disturbing faults

Area of the yarn body

Area of the disturbing faults

Fig. 3-1

Frequent and seldom-occurring yarn faults. Measured yarn length: 311,6 km.

The expected fault cuts for thin places calculated per 100 km is 4,5 (bottom, right corner). The total for thick and thin places is 100,5 per 100 km, which is too high as a cut rate. Therefore, the clearing curve has to be moved away from the yarn body. Since both dark and light green areas together constitute the yarn body, it is recommended that the clearer should not cut into the yarn body. If the clearing limit is laid within these green areas, the cuts will increase significantly and the productivity will be lower.

3.2

USTER® QUANTUM 3

3


Development of the yarn body / Example of Ne 30/1, 100% cotton yarn The clearing system calculates the yarn body already after a few seconds. The yarn body will be more accurate after some additional kilometers.

Fig. 3-2

Yarn body after 4,6 km

Fig. 3-3 Yarn body after 49,2 km

Fig. 3-4 Yarn body after 72,6 km

At the beginning the variation shown as the light green area is not yet stable due to the statistical calculations. But already after 30 km of running yarn the variation has stabilized and the optimization process for the clearing limits can start. There is practically no difference anymore between Fig. 3-3 and Fig. 3-4. If we calculate the duration of the above mentioned start-up for a link system with 23 winding positions and a stand-alone winding machine with 60 winding position, it results in the following time spans: Yarn length

Winder speed

Winding positions

Duration

Winding positions

Duration

4,6 km

1400 m/min

23

0,14 min

60

0,05 min

49,2 km

1400 m/min

23

1,53 min

60

0,59 min

72,6 km

1400 m/min

23

2,25 min

60

0,86 min

Examples of various yarn bodies

Fig. 3-5

Yarn body, cotton 100%, combed, knitting, 276 km (left), 238 km (right), count Nec 40, clearer C20, yarn with 39,4 cuts / 100 km on the left, yarn with 81,8 cuts / 100 km on the right.

USTER® QUANTUM 3

3.3

3


Fig. 3-6

Yarn body, polyester 100%, Nec 40, 523 km, knitting, (left), 382 km weaving, (right), clearer C15

Fig. 3-7

Yarn body, cotton 100%, carded, knitting, 413 km (left), 553 km (right), count Nec 40, clearer C15

Fig. 3-8

Yarn body, Nec 40, 35% cotton/65% viscose, weaving, 353 km (left), Nec 40, 55% cotton / 45% polyester, weaving, 361 km (right), clearer C15

3.4

USTER® QUANTUM 3

3


3.3

Interpretation of the yarn body

The Fig. 3-5 to Fig. 3-8 demonstrate that the shape of the yarn body strongly depends on the quality and the raw material of the yarn. For reasons of a better comparison the eight yarns are all of the same count. A comparison of yarn bodies of various counts and raw material has unveiled the following: •

Due to the higher irregularity the yarn body of carded yarns is wider than those of combed yarns

•

Since fine count yarns have a higher irregularity than coarse count yarns, the yarn body of fine yarns is wider than those of coarse yarns

•

The man-made polyester cut staple fibers have a significant effect on the light green area from 0,1 to 4 cm

•

The highest deviation of the yarn body from the zero line in the thin place area can be recognized at the mean length of the fibers, i.e. at about 2 cm, in blended yarns at about 3 cm.

•

The seldom-occurring faults (red dots) have a different but characteristic distribution. Therefore, an automatic determination of the clearing curve can minimize the number of cuts.

The yarn body, therefore, is a significant tool to only cut really disturbing faults and to optimize the number of cuts. The yarn body is affected by the yarn unevenness, by the number and type of thin places, thick places and neps, by the characteristics of the raw material and by the spinning process.

3.4

Disturbing thick places

3.4.1

Classification matrix

As already described in the introduction of this application handbook, seldom-occurring yarn faults are classified in the classification matrix of the USTER® CLASSIMAT. Besides the classification matrix, the cut thick places are divided in three groups (Fig. 3-9): •

N – faults: thick places from 0,2 cm to < 1 cm → very short thick places (S fault)

•

S – faults: thick places from 1 cm to < 8 cm

→ short thick places (L fault)

•

L – faults: thick places as of 8 cm

→ long thick places

USTER® QUANTUM 3

3.5

3


N

Fig. 3-9

S

L

Classification system for the settings N, S and L

Fig. 3-9 shows a setting example of the clearing curve when pressing the key NSLT. Fig. 3-10 shows the classification matrix of thick and thin places. With the help of new extended classes, the can monitor and control critical (e.g. short and fine) defects which often determine the fabric appearance.

Fig. 3-10

Classification matrix for NSL

For a broad understanding of the faults, it is recommended to base the assessment for the setting of the yarn clearer mainly on the evaluation of the yarn body and the scatter plot and less on the counts of the classification.

3.6

USTER® QUANTUM 3


3.4.2

3

Thick and thin places

Thick and thin places are evaluated by their visual impression, if they are disturbing or not-disturbing. The conversion into the "language" of the clearer, i.e. the fixing of the clearing limits, must be possible on the basis of the visual evaluation. Therefore, each modern yarn clearer must fulfill these conditions in order to measure all thick and thin places correctly. The determined values have to correlate to the size of the visual impression. Long thick and thin places can hardly be seen on the yarn itself, but are disturbing in the fabric. They require optimized calculation methods. These demands are fulfilled ideally with the USTER® QUANTUM 3. It is based on the calculation method already used in previous generations of the USTER® clearers and was proven to be best. Depending on the sensor type, the cross-section (iMH-C) or the diameter (iMH-O) are measured continuously with a repetition rate of 2 mm. This means: the clearer calculates the mass or the diameter of the yarn continuously every 2 mm length and determines the mass or the diameter of these sections. The fault determination starts, it is exceeding the mean value.

Positive threshold

Mean value (0%) Negative threshold

- 100% 2 mm pieces

Fig. 3-11

Yarn signal with threshold

Fig. 3-11 shows a yarn signal, for which a next test value is determined every 2 mm. Fig. 3-12 shows the yarn signal of a cotton yarn with two distinctive thick places and the deviation in percent. The first yarn fault has an increase of about 330%. In addition, one distinctive thin place is represented.

Fig. 3-12

Yarn signal of a cotton yarn with a clearing limit of 130% above the mean (0%)

USTER® QUANTUM 3

3.7

3


In Fig. 3-13, the signal of the first fault is enlarged.

Fig. 3-13

Enlarged yarn fault, first significant thick place, Fig. 3-13

All the displayed yarn faults of Fig. 3-14 show a classification length of 16 mm and were classified with a thickness between 260 and 300%. This picture is taken from the library of USTER® QUANTUM EXPERT for winding.

Fig. 3-14

Yarn faults with 260 – 300% and a length of 16 mm

The shown yarn faults (Fig. 3-14) serve as examples for the previously described fault. The example in Fig. 3-15 shows a long thick place with the classification 74% and 63 cm. If this classification point is entered into the classification matrix, it can be seen that the fault is situated above the clearing limit.

3.8

USTER® QUANTUM 3


3

74% 63 cm

Fig. 3-15

Example for a long thick place in the display window of the Control Unit

Long thick places starting at a length of 8 cm are classified as L-faults. The length of the L-faults is limited at 200 cm.

3.5

Clearing limits for thick places

The clearing limit is defined as a line which separates disturbing/cut faults from the nondisturbing/remaining faults. The course of the clearing limit is defined by setting parameters (see Fig. 3-16).

Fig. 3-16

Clearing limit of N, S and L by means of max 8 set points

For a good overview, the clearing limit is shown in the classification matrix. The classification matrix corresponds always to the set parameters.

USTER® QUANTUM 3

3.9

3


3.5.1

Standard way of optimizing clearing limits: Manual clearing limits entry

Fig. 3-17 shows the clearing limit as shown in the setting window of the Control Unit. At the previous generations of the USTER® QUANTUM, besides the clearing limit (NSL), the settings for the thick place clearing with the auxiliary setting points (H1…H6) is possible. Now the USTER® QUANTUM 3 gives us the chance of determining clearing limits by placing a maximum of 8 set points NSL1 to NSL8. In Fig. 3-17, we can see 4 setting points (red rectangle) and the clearing limit for NSL thick places. By this setting method the effects of a change of the parameters on the clearing limit can be demonstrated directly. As soon as we enter new values at set point, the next one will appear until we reach the 8th set point. This means after we enter the values for NSL1, set point NSL2 will appear and it will continue the same way.

Fig. 3-17

Clearing limits on the screen of the control unit

Set points have two parameters. These are: sensitivity (%) and reference length (cm). Sensitivity The sensitivity (%) is a parameter for the clearing limits of the corresponding fault channel. The sensitivity setting shifts the clearing limit upwards (less sensitive) or downwards (more sensitive). (NSL1 = 300%, Fig. 3-17). Reference length The reference length (cm) is a parameter for the clearing limits of the corresponding fault channel and shifts the clearing limit to the right (less sensitive) or to the left (more sensitive) (NSL1 = 1.0 cm, Fig. 3-17).

3.10

USTER® QUANTUM 3

3


3.5.2

Setting a smart clearing limit for disturbing thick places (NSL)

As we mentioned before, the yarn body is used for a better understanding of thick places, thin places and it shows the nominal yarn with its tolerable, frequent yarn faults. The aim of yarn clearing is to follow the course of the yarn body and to eliminate the thick and thin places which are disturbing in a fabric and which are outside the yarn body. Since the yarn body is clearly visible, clearing can follow the yarn body to minimize the number of cuts and to optimize the removal of disturbing faults. It also prevents from cutting into the yarn body and removal of defects that don't add value to the yarn but simply need additional splices which then could potentially break in the weaving process. In other words the default smart limit based on the yarn body is a nearly optimal clearing limit from a quality point of view (Fig. 3-18).

Pressing key presents • The yarn body. • Scatter plot of the cut faults and remaining events. • Number of expected fault cuts / 100 km. Clearing limit Red dots = cut yarn faults. Green dots = remaining events. =Yarn body variation =Yarn body = Proposes the starting point for the clearing limits based on the yarn body.

Fig. 3-18

Display of the yarn body and the actual clearing limit (thick places, NSL) with the forecasted cut values

The conventional way of optimizing the clearing limits is checking the existing ones by looking at the yarn test results and entering the new ones manually based on the customer’s own experience. However this procedure is time consuming, especially for a new , and needs some experience. With the USTER® QUANTUM 3, we have a very useful and smart tool to find the right starting point for the new clearing limits. The Smart Limit function proposes a starting point for the clearing limits based on the yarn body and also provides a cut forecast to facilitate faster setup of clearing limits. Fig. 3-20 shows the selection of the optimum clearing curve for thick places. For a few seconds or minutes the yarn runs with a pre-defined clearing curve (default value). After this period the operator can see the yarn body on the screen. Now the clearing curve can be optimized either by moving the clearing curve up or down. The setting can be fixed by pressing the “confirm” button.

USTER® QUANTUM 3

3.11

3


The setting of USTER® QUANTUM 3 can be done simply in one step:

Fig. 3-19

Start with standard setting

Fig. 3-20

Only one step / Press Smart Limit button and get a proposed setting including the cut forecast based on the yarn running

After pressing the Smart Limit key, a small window with the two appropriate keys to adapt and optimize the smart limit for NSL thick places appears. The Smart Limit has been developed to propose a starting point for the clearing limits by pressing one button. This proposal can be altered by open and close keys to optimize the settings according to the individual quality requirements and productivity. Every change of setting will automatically initiate a new calculation of the cut forecast. It is recommended to use the Smart Limit function after a minimum of 30 km of yarn has already been wound. Of course all settings recommended by smart limit can also be altered manually. Even in this case the new cut forecast is calculated.

= The new setting point proposals =

Smart Limit 1 step less sensitive.

=

Smart Limit 1 step more sensitive. = Show yarn body, scatter plot and recalculate the expected cuts / 100 km.

=

confirm and activate optimized clearing limit.

= Cancel all modifications Fig. 3-21

3.12

Proposed setting is a starting point for optimization

USTER® QUANTUM 3

3


Besides the smart limit function, of course the thick places (NSL) classes are still a very powerful tool where we can base our last decision.

Cuts/100km Total yarn fault counts /100 km in this class

Fig. 3-22

NSLT online classification

NSLT yarn faults are displayed together with all other yarn faults of the machine, a group or a winding position.

Fig. 3-23

NSLT yarn fault registration

USTER® QUANTUM 3

3.13

3


3.6

Disturbing thin places

Thin places, as long as they don't lead to yarn breaks, are only disturbing starting from a certain length. The reason for disturbing thin places is a missing number of fibers in the cross-section as a result of a non-optimal drawing process.

3.6.1

Classification matrix

As already described in the introduction of this application handbook, seldom-occurring yarn faults are classified in the classification matrix of the USTER® CLASSIMAT. The thin places are shown in the classification matrix, Fig. 3-24.

Fig. 3-24

3.7

Area of thin places in the classification matrix (red square)

Clearing limits for thin places

The evaluation of a thin place is similar to NSL

Fig. 3-25

3.14

Clearing limit for the T-channel

USTER® QUANTUM 3


3

Fig. 3-26 shows a long thin place with the classification -32% and 65 cm. This classification point, as shown in the classification matrix, is located outside the clearing limit (Fig. 3-26).

-32% 65 cm

Fig. 3-26

3.7.1

Example of a long thin place in the setting window of the control unit


Fig. 3-17 shows the clearing limit as shown in the setting window of the control unit. The USTER® QUANTUM 3 gives us the chance of determining our clearing limits by placing a maximum of 8 set points T1 to T8. In Fig. 3-17, we can see 5 setting points (red rectangle) and the clearing limit for T thin places. By this setting method the effects of a change of the parameters on the clearing limit can be demonstrated directly. As soon as we enter new values at set point, the next one will appear until we reach the 8th set point. This means after we enter the values for T1, set point T2 will appear and it will continue the same way.

USTER® QUANTUM 3

3.15

3


Fig. 3-27


Set points have two parameters. These are: sensitivity (%) and reference length (cm). Sensitivity The sensitivity (%) is a parameter for the clearing limits of the corresponding fault channel. The sensitivity setting shifts the clearing limit from the zero line away (less sensitive) or towards zero (more sensitive). (T1= -45%, Fig. 3-27). Reference length The reference length (cm) is a parameter for the clearing limits of the corresponding fault channel and shifts the clearing limit to the right (less sensitive) or to the left (more sensitive) (T1 = 2.6 cm, Fig. 3-27).

3.16

USTER® QUANTUM 3

3


3.7.2

Setting a smart clearing limit for disturbing thin places (T)

Fig. 3-28 shows the selection of the optimum clearing curve for thin places. For a few seconds or minutes the yarn runs with an automatically selected clearing curve (default value). After this period the operator can see the yarn body on the screen. Now the clearing curve can be optimized either by moving the clearing curve up or down. The setting can be fixed by pressing the “confirm” button (, Fig. 3-30). Pressing key presents • The yarn body. • Scatter plot of the cut faults and remaining events. • Number of expected fault cuts / 100 km. Red dots = cut yarn faults. Green dots = remaining events. =Yarn body variation =Yarn body = Proposes the starting point for the clearing limits based on the yarn body.

Fig. 3-28

Display of the yarn body and the actual clearing limit (thin places, T) with the forecasted cut values.

With the USTER® QUANTUM 3, the has a very smart tool to find the right starting point for the new clearing limits. The Smart Limit function proposes a starting point for the clearing limits based on the yarn body and also provides a cut forecast to facilitate faster setup of clearing limits. The setting of USTER® QUANTUM 3 can be done simply in one step:

Fig. 3-29

Start with standard setting

USTER® QUANTUM 3

Fig. 3-30

Only one step / Press smart limit button and get a proposed setting including the cut forecast based on the yarn running

3.17

3


After pressing the smart limit key, a small window with the two appropriate keys to adapt and optimize the smart limit for T thin places appears. The Smart Limit has been developed to propose a starting point for the clearing limits by pressing one button. This proposal can be altered by open and close keys to optimize the settings according the individual quality requirements and productivity. Every change of setting will automatically initiate a new calculation of the cut forecast. It is recommended to use the Smart Limit function after a minimum of 30 km of yarn has already been wound (Fig. 3-29 and Fig. 3-30). Of course all settings recommended by smart limit can also be altered manually. Even in this case the new cut forecast is calculated automatically.

= The new setting point proposals = Smart Limit 1 step less sensitive. = Smart Limit 1 step more sensitive. = Show yarn body, scatter plot and recalculate the expected cuts / 100 km. = confirm and activate optimized clearing limit. = Cancel all modifications

Fig. 3-31


Besides the smart limit function, of course the thin place (T) classification is still a very powerful tool where we can our last decision.

Cuts/100km Total yarn fault counts /100 km in this class

Fig. 3-32

3.18

NSL T online classification

USTER® QUANTUM 3

3


3.8

The effect of thick and thin places on the fabric appearance

3.8.1

Thick places

In Fig. 3-33, we see the ring spinning areas of faults and their descriptions. Ring Spinning Areas of Faults

Description S1 – Spun in fly waste S2 – Loose fly S3 – Long collections of fly waste

S4 – Faults caused by static charges or damaged aprons S5 – Collections of fly waste pushed together at the ring traveller

Fig. 3-33

Formation of faults on the ring spinning machine S1 Spun in fly This refers to free fibers which fall into the drafting elements or onto the roving being fed into the drawing unit. These fibers are then twisted into the yarn along their entire length

USTER® QUANTUM 3

3.19

3


Ring Spinning Areas of Faults

Description S2 Loose fly This refers to free fibers which are collected by the yarn at a position after the front roller and, in most cases, are only spun-in at one end.

S3 Long collections of fly These are fibers which stick together on aprons or rollers and from time to time are collected and carried along by the yarn.

S4 Fish (corkscrew-type faults) Faults caused by static charging or damaged aprons These faults occur due to static charging or are a result of unsuitable drafting aprons or drafting aprons which have cracked surfaces.

3.20

USTER® QUANTUM 3

3


Ring Spinning Areas of Faults

Description S5 Pushed-together collections of fly These are faults resulting from fibers which are held back, and occur primarily at the ring traveler.

S6 Chains of faults S1, S2, and S3 These are combinations of the faults S1, S2, and possibly also S3 which occur in short succession, one after the other, along the length of the yarn.

S7 Crackers This is due to extra long fibers which disturb the drafting process and, for a short instant of time, stop the age of the yarn.

Table 3-1 Spinning faults

In Fig. 3-34 to Fig. 3-43, there are various examples of thick place faults resulting from the spinning process. Thick places in a woven fabric are given in Fig. 3-34 to Fig. 3-35. Here we can see a spun-in fly failure (Table 3-1). This refers to free fibers which fall into the drafting elements or onto the roving which is being fed into the drawing unit and are then twisted into the yarn along their entire length.

USTER® QUANTUM 3

3.21

3


Fig. 3-34

Flying fibers which fall onto the roving or into the drafting elements and are then twisted into the yarn

Fig. 3-35

Thick place in woven fabric, type S4 (see Fig. 3-33, Table 3-1)

Fig. 3-36 to Fig. 3-38 show a red colored, 100% polyester T-shirt. Unless examined closely, the fault would go unnoticed. However, we have discovered a disturbing thick place fault in the following zoomed pictures (Fig. 3-37 and Fig. 3-38).

Fig. 3-36

Thick place in a T-shirt / 100% polyester

Fig. 3-37

Thick place in a T-shirt

Fig. 3-38

Thick place in a T-shirt, magnified

In Fig. 3-39 Fig. 3-40, a pair of 100% cotton jeans is shown as an example. We can see the long nonperiodic thick places in the weft yarn in the zoomed picture.

3.22

USTER® QUANTUM 3


3

There are two disturbing thick places in the white area (Fig. 3-40).

Fig. 3-39

Thick place in jeans / 100% cotton, Nec 18 (33 tex), OE rotor yarn

Fig. 3-40

Thick place in jeans, zoomed

Fig. 3-41 to Fig. 3-43 show ladies’ pants, produced from 100% cotton, OE rotor yarn. In the previous example (Fig. 3-39 and Fig. 3-40) the weft yarn has a long non-periodic thick place. But in the example in Fig. 3-41, the warp yarn has a long non-periodic thick place which can easily be noticed. In Fig. 3-42 and Fig. 3-43, the fault is magnified and indicated by an arrow.

Fig. 3-41

Thick place, ladies pants / 100% cotton, OE rotor yarn

Fig. 3-42

Thick place, ladies pants

USTER® QUANTUM 3

Fig. 3-43

Thick place, ladies pants, zoomed

3.23

3


3.8.2

Reasons and measures to minimize seldom-occurring thick places

In Table 3-2 and Table 3-3 the origin of the faults related to seldom-occurring events / thick places is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. SELDOM-OCCURRING EVENTS / Thick Places Origin of Faults Drawframe

Comber

Possible Reasons and Preventive Actions Improper function of the autolevelling at finisher drawframe can cause long thin and thick places in the slivers which will results in long thin and thick places in the yarns or even in wrong yarn count High short fiber content in sliver or roving Optimize comber settings (comber noil) in order to achieve the maximum short fiber removal

Roving frame

Spun-in fly waste from roving and spinning / Reduce flies in mill Improper draft distributions in drawing, roving, and spinning Wrong twist level in the roving Tension problems at roving frame Improper top roller pressure on roving frame

Ring spinning frame

Contamination too high / Cleaning of ring spinning machine regularly Improper distance settings of a traveler cleaner at the ring spinning machine Air condition system performance in spinning not under control Avoid high amount of end breaks because it will result in a high number of outlier bobbins and excessive fly formation Optimize previous process stages to avoid or minimize slubs Avoid poor yarn ts Avoid eccentric front rollers in roving and spinning Avoid fiber accumulations on rollers and aprons Avoid false draft in ring spinning machine creel or improper spinning draft distributions Aprons worn out or damaged Rings and ring travelers worn out Wrong settings of the travelling overhead cleaner Improper apron settings Incorrect choice of the traveler profile and weight Lint accumulation by rollers

Winding machine

Winding speed too high

Table 3-2 Preventive measures and tools for the management of seldom-occurring events / thick places

3.24

USTER® QUANTUM 3


3

®

SELDOM-OCCURRING EVENTS / Thick Places / USTER Tools for Improvement Tools

Improvement ®

Constant sliver quality and yarn quality

®

Adjustment of autolevellers

®

Proper settings of the clearing limits

USTER Testing off-line USTER Testing on-line USTER QUANTUM CLEARER

Monitor long-term quality level to secure consistency Separate outlier bobbins with quality data ®

USTER EXPERT SYSTEMS

Monitor long-term variation of cut ratio and yarn quality

Table 3-3 Preventive measures and tools for the management of seldom-occurring events / thick places

3.8.3

Thin places

Fig. 3-44 to Fig. 3-46 show two examples of thin places in knitted fabrics. Long thin places in yarns in the knitted fabric result in a severe defect. As illustrated in Fig. 3-45, the weak spots in the yarn gave in after five washing cycles and caused holes in the fabrics.

Fig. 3-44

Long thin places in yarns in the knitted fabric result in a severe defect

Fig. 3-45

Hole in a knitted fabric after five washing cycles

Fig. 3-46 shows a T-shirt with thin places. Although produced from 100 % combed cotton yarn, the thin places show up as horizontal lines.

USTER® QUANTUM 3

3.25

3


Fig. 3-46

Thin places in knitted T-shirt / 100% cotton, combed

Fig. 3-47 and Fig. 3-48 show a T-shirt with two horizontal lines, produced from 100% carded cotton yarn. These lines, indicated by two black arrows, were produced by a yarn with a smaller diameter (long thin places) than the normal yarn which has then caused thin places in the T-shirt.

Fig. 3-47

3.26

Thin places in cotton T-shirt / 100% cotton, carded, Ne 26 (22,5 tex)

Fig. 3-48

Thin places in cotton T-shirt, magnified

USTER® QUANTUM 3

3


3.8.4

Reasons and measures to minimize seldom-occurring thin places

In Table 3-4 and Table 3-5, the origin of the faults related to seldom-occurring events / thin places is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. SELDOM-OCCURRING EVENTS / Thin Places Origin of Faults

Possible Reasons

Drawing frame

Improper function of autolevelling at finisher drawframe can cause long thin and thick places in the slivers which will results in long thin and thick places in the yarns or even in wrong yarn count

Roving frame

High unevenness of roving Tension problems in roving Weak roving Eccentric front rollers Aprons worn out

Ring spinning frame

False draft in ring spinning machine creel Eccentric front rollers Aprons worn out Blocked trumpets Blocked drafting cages Missing instruction and training of operators Apron worn out or damaged

Winding

High winding speed and winding tension

Table 3-4 Preventive measures and tools for the management of seldom-occurring events / thin places ®

SELDOM-OCCURRING EVENTS / Thin Places / USTER Tools for Improvement Tools

Improvement ®

Systematic quality control of sliver quality with the USTER TESTER

®

Adjustment of autolevellers

®

Proper setting of the clearing limits


®

Separate outlier bobbins with quality data software of the clearer ®



Table 3-5 Preventive measures and tools for the management of seldom-occurring events / thin places

USTER® QUANTUM 3

3.27

3

3.28


USTER® QUANTUM 3

Count variations

4

Count variations

4.1

Introduction

4

Deviations of the yarn count within a yarn lot lead to high costs for complaints. The fact that the faulty yarn deviates from the nominal count can cause quality problems in the end product. The reasons for count variations are diverse: •

Deviations by mixing in wrong bobbins

•

Peeled-off or uneven rovings can lead to significant count deviations within a bobbin

•

Missing sliver from a finisher drawframe without an autolevelling system

This demands a reliable monitoring of the yarn count on one side, but also its precise setting, which is in accordance with the quality requirements of the yarn. This can be done in many ways. In the following, two possibilities are described: •

The C-channel monitors the yarn count in the start-up phase after the splicing process. During this phase, mainly bobbins with the wrong count are ed, and the winding position must be stopped with the corresponding alarm functions. After the start-up phase, the C-channel is not active anymore. This procedure allows the choice of very sensitive settings, which are adjusted to the special circumstances of the start-up phase of the winding position.

•

The CC-channel monitors the yarn count over the whole winding process. It is also possible to monitor very long yarn faults with the CC-channel dependent on the choice of the settings.

4.2

Definition of the yarn body for long-term variations (C and CC faults)

The "yarn body" represents the nominal yarn with its tolerable, frequent yarn faults. Yarn body is a new yarn characteristic, and we know from the experience so far that the yarn body changes according to the raw material and the spinning process. By analyzing the shape of the yarn bodies out of different raw material varieties and process changes, we can discover patterns, and build up references. Based on the references, the operator can identify changes. The yarn body becomes always wider in the direction of the short yarn events, e.g. short faults occur more frequently. On the contrary, the yarn body becomes smaller in the direction of the long yarn events. The USTER® QUANTUM 3 interprets and displays the yarn characteristics with the help of the yarn body. The yarn body is a great tool to help finding the optimum clearing limits for thick places (NSL), thin places (T), yarn count deviations (C) and (CC). The yarn body for CC is composed of two parts: •

Dark green area representing the real yarn body

•

Light green area representing yarn body variations

USTER® QUANTUM 3

4.1

4

Count variations

The yarn body for C is composed of two parts (Fig. 4-1): •

Dark green line representing the real yarn body.

•

Light green line representing yarn body variations.

Fig. 4-1

Yarn body display for C, defined from 2 to 12 m

The vertical scale represents the yarn mass or diameter increase and decrease, and the horizontal axis represents the fault length in meter. Fig. 4-2 represents the yarn body for CC-fault. In Fig. 4-2 the green shaded area represents the yarn body for medium and long-term variations (2 to 12 m).

Fig. 4-2

Yarn body display for medium and long-term variations (CC faults), defined from 2 to 12 m

The vertical scale represents the yarn mass or diameter increase and decrease, and the horizontal axis represents the faults length in meter. Since both dark and light green areas together constitute the yarn body, it is recommended that the clearing curve should not touch the yarn body. If the clearing limit is laid within these green areas, the cuts will increase significantly and the productivity will drop.

4.2

USTER® QUANTUM 3

Count variations

4.3

Count deviations

4.3.1

Determination of the mean value of a yarn

4

The pre-condition for an exact monitoring of yarn count deviations is the correct determination of the nominal yarn count. With the command "Start article" the parameters of C and CC are switched to a less sensitive fixed value in order to avoid wrong cuts during the calibration process. After the start-up of the winding position, each sensor determines the mean value for the running yarn and forwards it to the Central Clearing Unit. The Central Clearing Unit (CCU) calculates the mean value from all the transmitted values and sends it back to the sensors.

4.3.2

Purpose of yarn count deviation monitoring

Deviations of the yarn count within a yarn lot lead to high costs for complaints. The fact that the faulty yarn deviates over several meters or even longer from the nominal count can cause quality problems in the end product. This demands a reliable monitoring of the yarn count on one side, but also its precise setting, which is in accordance with the quality requirements of the yarn. Fig. 4-3 shows the possibilities for yarn fault monitoring, if the fault channels N, S, L, C and CC are active.

Fig. 4-3

Clearing limits N, S, L, T, C+, C-, C and CCm

USTER® QUANTUM 3

4.3

4

Count variations

4.3.3

Monitoring of yarn count deviations during start-up in the C – channel

Objective The recognition of count deviations after the splicing process must be carried out very quickly, before too much yarn is wound on the cone. The pre-conditions during the start-up phase are not always perfect for a very sensitive monitoring. Therefore the monitoring must be carried out over a certain yarn length, in order to avoid wrong cuts. All modern winding machines are able to remove detected count deviations by setting a reference length on the clearer. Count variations in the start-up phase must be monitored with the C-channel. The thresholds for the clearer are set with the following parameters: •

sensitivity setting for the detection of yarn diameter or mass increases

•

Cm sensitivity setting for the detection of yarn diameter or mass decreases

•

Reference length

The choice of the thresholds depends on different factors and must be adjusted to the conditions of the mill: •

the produced yarn counts of the spinning mill

•

the evenness of the yarn

•

the possibilities of the winding machine to determine the suction length

Function With each start-up, the C-channel monitors the yarn over the set reference length. The sensor measures the mean value over this length. If the mean value exceeds the above limits, a cut follows. Yarn suction after a C-cut / Machines with fault-related yarn suction Up-to-date winding machines provide measurable, fault-related yarn suction. The sensor transmits the length of a or Cm cut to the processor of each individual winding position and determines the length to be sucked-off. As deviations from the nominal count can be calculated more precisely over a larger reference length it is recommended to choose the cut length on machines with a fault related yarn suction as long as possible. However, one has to pay attention that no back-windings occur during the suctioning of the yarn. In practice, lengths of 6 to 8 meters proved to show the best results. For very critical applications lengths of 12 to 20 m are recommended.

4.4

USTER® QUANTUM 3

Count variations

4.3.4

4

Monitoring of the yarn count while winding with the CC-channel

Objective •

The reasons for deviations from the yarn count are numerous and vary from mill to mill. In the end product, such events are only disturbing because of their length.

•

By the draft, a faulty deviation can consists of several short, subsequent deviations, which are only disturbing as a whole in the end product.

The recording of count variations and very long yarn faults takes place in the CC-channel, even when they are interrupted by normal pieces of yarn. The yarn is monitored with two independent clearing limits. The parameters for the clearer are given with the following settings: •

C sensitivity setting for the monitoring of mass and diameter increases

•

CCm sensitivity setting for the monitoring of mass and diameter decreases

•

Reference length is set for different length classes between 2.0 and 12.0 meters

Function In contrast to the C-channel, the CC-channel is active over the whole winding length. Therefore, a different kind of signal evaluation is applied. A mean value is continuously calculated. Short drops of the yarn count have only a minor effect on the total result of the continuous mean value. If the continuous mean value exceeds the above set sensitivity, a CC-cut is triggered.

Fig. 4-4

USTER® QUANTUM 3

4.5

4

Count variations

Yarn suction after a CC-cut / Machines with fault-related yarn suction Modern winding machines provide a measurable, fault related yarn suction. The winding position gets the information from the yarn clearer, how much yarn has to be sucked-off before the splice is carried out.

4.4

C and CC settings

The C-channel monitors the yarn count in the start-up phase after the splicing process. After the startup phase, the C-channel is not active anymore. As already known from USTER® QUANTUM 2, the Cchannel can be set for one reference length and a plus () and minus (Cm) limit. The CC-channel monitors the yarn count during the whole winding process. Depending on the setting long yarn faults with a small mass or diameter increase can be detected. This new CC-channel is able to detect and remove count variations at different cut length between 2 m and 12 m. For the CC-channel a smart limit proposal is available to find a good setting taking the variation of the current production into consideration.

Fig. 4-5

4.4.1

Display of C setting, only one reference length to be set

Fig. 4-6

Display of CC setting. Smart limits available for length classes from 2 – 12 meters.

Yarn count deviations at start up (C) settings

The C-channel monitors the yarn count in the start-up phase after the splicing process. After the startup phase, the C-channel is not active anymore. In the example of Fig. 4-7 the (plus) setting is 10% and the Cm (minus) setting is -10%. The reference length (C) is 6 m.

4.6

USTER® QUANTUM 3

4

Count variations

Pressing key presents • The yarn body. Clearing limit A rea of actual yarn count. Red dots = cut yarn faults

Fig. 4-7

Display of C setting, only one reference length to be set

Scatter plot of yarn count monitoring at start-up / Practical example

Fig. 4-8

Yarn Ne 40, cotton 100%, combed, compact, capacitive sensor, 1010 km. Too short reference length (2m) adjustment and too many cuts. It is recommended changing the reference length to 6m or 8m

USTER® QUANTUM 3

4.7

4

Count variations

Fig. 4-9

4.4.2

Yarn Ne 24, cotton 100%, carded, capacitive sensor, 10035.2 km. Open settings, reference length is 10 m.

Fig. 4-10 Yarn Ne 24, cotton 100%, carded, capacitive sensor, 3067.9 km. Close settings, reference length is 10 m.

Setting a smart clearing limit for yarn count monitoring (CC)

The CC-channel monitors the yarn count during the whole winding process. Depending on the setting, long yarn faults with a small mass or diameter increase can be detected. This new CC-channel is able to detect and remove count variations at different cut lengths between 2 m and 12 m. The setting points are: •

2 Set points: C +% at 2 m and 12 m

•

2 Set points CCm -% at 2 m and 12 m.

The lines between the set points represent the clearing limit. Fig. 4-11 shows the yarn body and the actual clearing limit for CC. For a few seconds or minutes the yarn runs with an automatically selected clearing curve (default value). After this period the operator can see the yarn body on the screen.

4.8

USTER® QUANTUM 3

Count variations

4

Pressing key presents • The yarn body. • Scatter plot of the cut • Number of cuts / 100 km. Clearing limit Red dots = cut yarn faults. =Yarn body variation =Yarn body = Proposes the starting point for the clearing limits based on the yarn body.

Fig. 4-11


By pressing Smart Limit function a proposed starting point for the CC settings will be selected. According to the need of the customer this proposal can be accepted or modified with the smart limit function or manually.

Fig. 4-12

Start with standard setting. Press Smart Limit key

Fig. 4-13 Only one step / Display of CC setting, smart limits available for length classes from 2 – 12 meter

After pressing the Smart Limit key, a small window with the two appropriate keys to adapt and optimize the smart limit for CC appears. The Smart Limit has been developed to propose a starting point for the clearing limits by pressing one button. This proposal can be altered by up and down keys to optimize the settings according to the individual quality requirements and productivity. It is recommended to use the Smart Limit function after a minimum of 30 km of yarn has already been wound.

USTER® QUANTUM 3

4.9

4

Count variations

Of course all settings recommended by smart limit can also be altered manually. As soon as the button at the smart limit window is pressed, the yarn body and scatter plot is displayed on the setting page.

= The new setting point proposals = Smart Limit 1, step less sensitive. = Smart Limit 1, step more sensitive. = Show yarn body and scatter plot = confirm and activate optimized clearing limit. = cancel all modifications

Fig. 4-14


C and CC faults are displayed together with all other yarn faults of the machine, a group or a winding position.

Fig. 4-15

4.10

C and CC fault reports

USTER® QUANTUM 3

Count variations

4

Scatter plot of medium-term deviations / Practical example

Fig. 4-16

Fig. 4-17

Frequent medium-term deviation of the count. Analysis of the spinning process required.

Yarn Ne 40, cotton 100%, carded, knitFig. 4-18 ting, capacitive sensor, 1582 km. Low number of count deviations within the range of 2 to 12 m, 0,8 + 0,2 = 1,0 per 100 km.

USTER® QUANTUM 3

Yarn Ne 32, cotton 100%, carded, knitting, capacitive sensor, 3496 km, wider yarn body, same clearing curve as seen on the left hand side. High number of count deviations between 2 and 12 m, 3,4 + 1,5 = 4,9 per 100 km.

4.11

4

Count variations

Fig. 4-19

4.5

Yarn Ne 12, cotton 100%, carded, weaving, capacitive sensor, 771 km. High number of count deviations within the range of 2 to 12 m, 8,3 + 2,6 = 10,9 per 100 km.

Fig. 4-20 Yarn Ne 16, cotton 100%, carded, weaving, optical sensor, 492 km. Low number of count deviations within the range of 2 to 12 m, 4,1 + 2,0 = 6,1 per 100 m.

Calculation of yarn count deviations

The determination of the setting parameters for the yarn count deviation monitoring must be carried out very carefully. Different aids are at disposal. •

Determination of count variations with the clearer installation

•

Calculation of the count variations with formulas

•

Determination of count variations with a diagram

•

Determination of count variations with the USTER® Calculator

4.5.1

Determination of count deviations with the clearer installation

As described before, the mean value of the yarn is determined from the single winding positions and is detectable as the V-value at the Control Clearing Unit. This means, this value presents the 100% - value of the yarn. This value can also be used for the calculation of deviations between bobbins. The V takes factors like the material or the relative humidity already into . It is possible to calculate the count deviation in percent according to the following formula: Formula 1: Mass deviation( %) =

V =

4.12

Wrong yarn B( V) − yarn A( V) ⋅ 100% yarn A( V)

Yarn mean value / value which is generated by the sensor as an electrical signal when inserting a yarn in the measuring slot.

USTER® QUANTUM 3

4

Count variations

Example 1: Article A is mixed up with a coarser yarn, article B (capacitive measurement) •

Article A:

Ne 30

V: 776

•

Article B:

Ne 20

V: 1204,2

Mass deviation( %) =

Wrong yarn B( V) − yarn A( V) 1204,2 − 776,0 × 100 = 55,2% ⋅ 100% = 776,0 yarn A( V)

This means, that the difference between Ne 30 and Ne 20, measured with the capacitive sensor, results in a mass increase of 54,6%.

Example 2: Article A is mixed up with a coarser yarn, article B (optical measurement) •

Article A:

Ne 30

V: 4578,4

•

Article B:

Ne 20

V: 5513,6

Diameter deviation( %) =

Wrong yarn B( V) − yarn A( V) 5513,6 − 4578,4 ⋅ 100% = × 100 = 20,4% yarn A( V) 4578,4

This means, that the difference between Ne 30 and Ne 20, measured with the optical sensor, results in a diameter increase of 20%. The percentage differences are limits. They should only be used as a guideline for the C- and CCsettings. Experience has shown that a certain tolerance must be taken into . This means, the selected settings should be lower than the calculated values.

4.5.2

Calculation of the count deviations of wrong bobbins (capacitive measurement)

Count deviations between yarns of the same fiber material For the iMH-C count deviations can be determined according to formula 1 below:

Formula 2: Mass deviation( %) =

Wrong yarn B( tex) − yarn A( tex) ⋅ 100% yarn A( tex)

Example 1: Article (yarn A) is mixed up with a finer yarn Yarn A (33,3 tex) is mixed up with yarn B (25 tex) ( B − A) − 8,33 ( 25 − 33,3) Mass deviation( %) = ⋅ 100% = ⋅ 100% = = −25% A 33,3 33,3

USTER® QUANTUM 3

4.13

4

Count variations

Example 2: Article (yarn A) is mixed up with a coarser yarn Yarn A (25 tex) is mixed up with yarn B (33,3 tex) ( B − A) ( 33,3 − 25) 8,33 Mass deviation( %) = ⋅ 100% = ⋅ 100% = = +33% A 25 25

Count deviations between yarns of different fiber material If count deviations between yarns of different fiber material in blended yarns should be monitored, the deviations can be calculated with formula 2 below. The different material factors have to be taken into . Formula 3: Mass deviation( %) =

value of yarn B −( yarn A × factor) ⋅ 100 % A × factor

Yarn material

Factors

Relative humidity

0,86

80%

0,77

65%

0,69

50%

Acetate, Acrylic, Polyamide

0,62

65%

Polypropylen, Polyethylene

0,56

65%

Polyester

0,50

65%

Polyvinylchloride

0,45

65%

Cotton, wool, viscose

Table 4-1

Factors of the yarn material

Example 3: Article A made out of Polyester is mixed up with article B made out of cotton Yarn A: 20 tex: 20 x factor 0,5 = 10 Yarn B: 20 tex: 20 x factor 0,77 = 15,4 Mass deviation =

15,4 − 10 ⋅ 100% = + 54% 10

Example 4: Article A made out of cotton is mixed up with article B made out of Polyamide Yarn A: 27, 8 tex: 27,8 x factor 0,77 = 21,4 Yarn B: 23,8 tex: 23,8 x factor 0,62 = 14,8 Mass deviation( %) =

14,8 − 21,4 ⋅ 100% = − 31% 21,4

If the wrong bobbins deviate from the nominal yarn with respect to yarn material and yarn count, then the mass deviation has to be calculated according to formula 3:

4.14

USTER® QUANTUM 3

Count variations

4

Example 5: Article A made out of cotton (20 tex) is mixed up with blended yarn B PES/CO 67/33% (19,2 tex) Yarn A: Yarn B:

20 tex: 20 x factor 0,77 = 15,4 19,2 tex: (B x factor PE x %-share) + (B x factor CO x %-share) = (19,2 x 0,5 x 0,67) + (19,2 x 0,77 x 0,33) = 11,3

Mass deviation( %) =

11,3 − 15,4 ⋅ 100% = − 27% 15,4

In order to compensate the variation of the yarn count, the channels C and CC should be set to an about 5% more sensitive value than the calculated value.

4.5.3

Calculation of count variations of wrong bobbins – optical measurement

As the iMH-O measures the yarn diameter, the count deviations must be converted in differences of the yarn count. This can be done quite easily with the aid of the USTER® Calculator (see section 4.5.5). •

Determination of the mass deviation according to the following examples 1 and 2.

•

Conversion of the mass deviation to diameter deviations with the help of the USTER® Calculator.

Example 1: Article A (33,3 tex) is mixed up with bobbins B (25 tex) Mass deviation( %) =

B−A −8,33 ⋅ 100% = ⋅ 100% = − 25% A 33,3

-25% mass deviation  -13% diameter deviation Example 2: Article A (25 tex) is mixed up with bobbins B (33,3 tex) Mass deviation( %) =

B−A +8,33 ⋅ 100% = ⋅ 100% = + 33% A 25

+33% mass deviation  +16% diameter deviation It has to be taken into that with the optical monitoring of wrong bobbins, the diameter deviations are percentage-wise smaller than mass deviations. In order to compensate the variation of the yarn count, the channels C and CC should also be set about 5% more sensitive than the calculated values.

USTER® QUANTUM 3

4.15

4

Count variations

4.5.4

Calculation of count variation of wrong bobbins with a diagram

The following diagram can only be used for the calculation of count variations when the capacitive measuring head is used. %

-50 -45 -40 -35 -30 -25 -20 -15 -10

-5 +5

130

B

Nm/Nec

+10 +15 +20 +25 +30 +35 +40 +45 +50

120 110

1

100 90 80

%

70 60 50 40 30

2

20 10

A 10

Fig. 4-21

20

30

40

50

60

70

80

90

100

110

Nm/Nec

120

130

140

Determination of the mass deviation of yarns made out of the same material, but with a different count

Fig. 4-21 shows two examples for the calculation of mixed-up bobbins: Example 1: article A, Ne 68 is mixed with yarn B, Ne 80 → deviation = -15% Example 2: article A, Ne 50 is mixed with yarn B, Ne 40 → deviation = +25% → When this calculation is carried out in tex, the values A and B must be reversed.

4.16

USTER® QUANTUM 3

Count variations

4.5.5

4

Relationship between the mass and diameter deviation with the USTER® Calculator

In this section, only the relationship between the mass and diameter deviations will be explained, which can be calculated with the aid of the USTER® Calculator. Scales ± and ″ of the calculator serve for this purpose.

Fig. 4-22

®

Conversion of mass and diameter deviations with the USTER Calculator (6 = diameter scale, 7 = mass scale)

Depending on the measuring method and the unit which is used, the sliding tongue must be adjusted. Example from Fig. 4-22: A mass deviation of 50% (7) corresponds to a diameter increase of only about 22% (7). Determination of the yarn count deviation with the USTER® Calculator For the setting of the C- and the CC-channel, the value, which a wrong yarn must deviate in order to be recognized, must be entered in percent. Example: 1. First, the correct yarn count must be set with the vertical line of the Calculator. In case of Fig. 4-23, it is Nm 20 and 50 tex, respectively. 2. Furthermore, depending on the measuring method (capacitive or optical) the sliding tongue of the Calculator must be moved so that the tongue for the spun yarn is on the "0" mark.

USTER® QUANTUM 3

4.17

4

Count variations

Fig. 4-23

®

Setting of the USTER Calculator (1)

3. If a wrong yarn with the count Nm 18,5 (54 tex) should be detected, the sliding tongue must be set on this count (see Fig. 4-24). 4. Then, in the middle of the Calculator (area marked red), the corresponding deviation in percent can be read on the scale. In this case, Fig. 4-24, for the optical sensor it is 4%, for the capacitive sensor it is 8%. The same procedure must be carried out for negative deviations.

Fig. 4-24

4.6

®

Settings of the USTER Calculator (2)

Example for the setting of the C-channel

For the choice of the right setting of the C- and CC-channel, the scatter plot serves as a helpful tool. The scatter plot shows the unevenness of a yarn, even for longer yarn pieces, very well. For the correct setting of the channels it is necessary to know which faults were defined as not tolerable by customers. It is also necessary to know the possibilities of the winding machine regarding the setting of the suction length.

4.18

USTER® QUANTUM 3

Count variations

4

From all this information, the settings for the clearer can be derived. An example for a correct setting is explained in the following: A spinning mill produces three different cotton yarns: Ne 20, Ne 30 and Ne 40. It is possible with a normal unevenness of yarns to distinguish mixed up bobbins of these 3 yarn counts. The setting of outlier or mixed-up bobbins is: •

iMH-C

: +24% Cm: -20% Reference length: min. 2 m or adjusted to the winding machine type

•

iMH-O

: +12% Cm: -10% Reference length: min. 2 m or adjusted to the winding machine type

Due to the normal unevenness of a cotton yarn, it can be predicted that a more sensitive setting of /Cm can lead to unjustified cuts. It can also be said that the detection of counts anywhere between Ne 20, Ne 30 and Ne 40 (e.g. Ne 24 out of a Ne 20) cannot be guaranteed anymore. Rule of thumb for iMH-C: The setting for the C-channel with a reference length of 2 to 4 m should not be set more sensitive than the CVm of the yarn. Rule of thumb for iMH-O: The setting for the C-channel with a reference length of 2 to 4 m should not be set more sensitive than 70% of the CVm of the yarn.

4.7

The effect of count deviations on the fabric appearance

4.7.1

Mixing two different yarn counts

Bobbins with different yarn counts can be accidentally mixed up during yarn production, or there can be count deviations within a cone. These count deviations can cause long stripes in the fabrics which are visible to the naked eye.

In this example, we have knitted ten rows of reference yarn (Nec 30, 20 tex) and ten rows of a finer yarn (Nec 34, 17,5 tex) spun from the rovings produced by using the same cotton blend, using the ring spinning method. We can observe horizontal dark and light colored lines in both the grey (Fig. 4-25 and Fig. 4-26) and the dyed samples (Fig. 4-27 and Fig. 4-28). These horizontal lines are the result of yarn count differences. There is also a difference between the diameter 2DØ values of these two yarns (Table 4-2).

USTER® QUANTUM 3

4.19

4

Count variations

Reference

Yarn Count (Ne)

Twist 1/m

Twist direction

CVm %

Thin 50%

Thick +50%

Neps +200%

H

2DØ mm

CV2D (8mm)

D (abs) 3 g/cm

30

830

Z

12.7

0.5

34.5

66

4.6

0.22

9.6

0.5

61

29

71

73

22

34

883

Z

13.5

6.0

52.5

90

4.5

0.20

10.3

0.5

77

>95

82

77

25

USP07 Wrong count USP07

Table 4-2

18 27

Yarn quality results

USP07 = USTER® STATISTICS 2007 2DØ

= Optically measured diameter with the USTER® TESTER 5 / Measurement of the yarn diameter with 2 light beams of 90 degrees

D

= Density measured with the USTER® TESTER 5

Fig. 4-25

4.20

Reference fabric (grey)

Fig. 4-26

Defective fabric (mix-up of reference yarn with a finer count yarn) (grey)

USTER® QUANTUM 3

4

Count variations

Fig. 4-27

Reference fabric

Fig. 4-28

Defective fabric (mix-up of reference yarn with a finer count yarn)

In a similar trial, we have used ten rows of a coarser yarn (Nec 26, 22,5 tex) and ten rows of reference yarn (Nec 30, 20 tex) and produced knitted fabric samples. Again in both the grey and the dyed samples, we can observe horizontal dark and light colored lines. As mentioned previously, these horizontal lines are the result of yarn count differences. There is also a difference between 2D-diameter values of these two yarns (Table 4-3). The pictures are not shown here, as the appearance of the previous sample (with finer yarn) and this one are very similar.

Reference

Yarn Count (Ne)

Twist 1/m

Twist direction

CVm %

Thin -50%

Thick +50%

30

830

Z

12.7

0.5

61

29

12.0 50

USP07 Wrong count

26

770

USP07

Table 4-3

Z

Neps +200%

H

2DØ mm

CV2D (8mm)

D (abs) 3 g/cm

34.5

66

4.6

0.22

9.6

0.5

71

73

22

0.0

22.0

32.5

4.9

<5

60

54

32

18 0.24

9.5

0.5 27


In another example, we have knitted 10 rows of reference yarn (Nec 36, 16,5 tex) and 10 rows of a coarser yarn (Nec 30, 20 tex) spun from the rovings produced by using the same cotton blend.

USTER® QUANTUM 3

4.21

4

Count variations

Then the knitted fabrics were dyed and T-shirt samples were produced. In the fabric and the T-shirt sample, we can observe horizontal dark and light colored lines (Fig. 4-29 to Fig. 4-32). These horizontal lines are the result of yarn count difference (Table 4-4). Both yarns have the same evenness, but as a result of different counts the diameter is different.

Reference

Yarn Count (Ne)

CVm %

Thin -50%

Thick +50%

Neps +200%

H

2DØ mm

CV2D (8mm)

D (abs) 3 g/cm

36

12.6

0.6

33.1

71.7

5.2

0.20

9.6

0.5

48

19

61

65

76

12.6

0.90

33.8

52.3

5.6

50

32

62

52

90

USP07 Wrong count USP07

30

Table 4-4


Fig. 4-29

Reference T-shirt

Fig. 4-31

Reference fabric

4.22

Fig. 4-30

Fig. 4-32

40 0.23

9.8

0.5 55

Defective T-shirt (mix-up of reference yarn with a coarser count yarn). Stripes in the direction of the arrow (see also Fig. 4-32).

Defective fabric (mix-up of reference yarn with a coarser count yarn)

USTER® QUANTUM 3

4

Count variations

4.7.2

Reasons and measures to minimize count variations

In Table 4-5 and Table 4-6, the origin of faults related to long-term mass variations is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. Yarn Count Variation Origin of Faults

Possible Reasons and Preventive Actions

Drawing frame

Use autoleveller on finisher drawframe

Roving frame

Weight variation of rovings Check roving trumpet hole diameter and cleanliness at the trumpet input Use different color of roving tubes to avoid roving count mix-ups

Ring spinning frame

Improper roller weightings Spinning creel alignments Dragging bobbin holders Blocked spinning trumpet False draft in ring spinning machine creel Instruction and training of operators Use of different colors of spinning tubes to avoid count mix-ups

Table 4-5

Preventive measures and tools for the management of long-term mass variations

®

Yarn Count Variation / USTER Tools for Improvement Tools

Improvement ®

®

Constant quality control of sliver and yarn quality with the USTER TESTER

®

Adjustment of autolevelling system

®

Separation of outlier bobbins with quality data software of the yarn clearer


Correct settings of C and CC channel Use C and CC alarm settings for eliminating wrong spinning bobbins ®

USTER EXPERT SYSTEMS Table 4-6


Preventive measures and tools for the management of long-term mass variations

USTER® QUANTUM 3

4.23

4

4.24

Count variations

USTER® QUANTUM 3

Splice Clearing

5.

Splice Clearing

5.1

Introduction

5

A splice, also called yarn t, has the purpose to two ends of a yarn as a result of yarn fault removal on OE rotor and winding machines and bobbin changes during the winding process. This means: when a detected fault is eliminated, the resulting yarn ends are pieced together by an automatic splicing device [1]. In the past, it was common practice to knot yarns together, but the knots were a source of weakness and could also lead to problems in subsequent processes. Nowadays, yarns are spliced using mechanical splicers, air-jet splicers, water-jet splicers, thermo-splicers, etc. which produce a t that is usually at least 70% of the strength of the mean yarn strength, and generally less than 130% of the thickness of the parent yarn. The splice efficiency is used as a measure of the spliced part of the yarn, expressed as percentage strength of the reference yarn. The adoption of splicing has greatly reduced problems in weaving, knitting, and dyeing [2]. A yarn must have a certain minimum tensile strength and a minimum elongation in order to stand up to the processes subsequent to spinning. This is also and especially valid for splices that together two ends of a yarn. Since an average count ring-spun yarn can have more than 100 splices over a length of 100 km, it is important to monitor the parameters of the splices carefully. Besides the quality aspect that needs to be fulfilled by the yarn, its processing quality depends to a certain extent also on the quality of the splices. Today, approximately one splice per kilometer has to be expected in a cone. Considering the costs for a yarn break in knitting, warping, sizing or weaving, the splices play an important role in this respect as well. The number of splices must be kept at a low level, but the potential weak places must have the highest strength possible. This is only possible by checking the strength of the splices regularly by means of an instrument.

5.2

Scatter plot of splices

The USTER® QUANTUM 3 interprets and displays the splice characteristics with the help of a scatter plot. It is the graphic representation of the thickness and length within a classification matrix. Each splice is marked with one dot. The vertical scale represents the yarn mass or diameter increase and decrease of a splice and the horizontal axis represents the splice length in cm. Fig. 5-1 shows a scatter plot with splices as seen by the USTER® QUANTUM 3, with all the splice recorded (green dots), the actual clearing limit and the area of the disturbing splices (red dots) which exceed the maximum and minimum issible splices. The scatter plots are used to visualize the optimum clearing limits for both the Splice Clearing (Jp/Jm), and for such events the graphical display of a scatter plot matches the demands of the customers best. The scatter plot for Splice Clearing (Jp/Jm) represents the classified splices. The USTER® QUANTUM 3 classifies the thickest (Jp, Fig. 5-1, red circle) and thinnest (Jm, Fig. 5-1, blue circle) event for every splice and show them on the scatter plot. The active clearing limit of the Jp splice clearing limit is highlighted with red color on the setting page (Jp = t, positive).

USTER® QUANTUM 3

5.1

5

Splice Clearing

Fig. 5-1

Splice distribution. Measured yarn length: 216 km

In the display main menu, it is possible to display either scatter plot of splices alone (Fig. 5-2) or together with the scatter plot of disturbing thick and thick places (NSLT) (Fig. 5-3). Fig. 5-3 shows a regular distribution of splices (dark green dots) together with the scatter plot of the thick and thick places (light green dots). This combined scatter plot is a very helpful tool to show the localization and the distribution of splices compared to the remaining thick and thin places in the yarn. With the help of this combined graph, it is very easy to compare the splices to the natural events in the yarn and to avoid unnecessary splices because it makes no sense to replace a small fault by a bigger splice.

Fig. 5-2

Scatter plot of splices with the clearing curves for thick/thin places and splices

Fig. 5-3

Scatter plot of splices and thick/thin places together

The scatter plot of splices demonstrates the performance of the splicer and shows the position of the outliers.

5.2

USTER® QUANTUM 3

Splice Clearing

5

Examples of various scatter plots for splices.

Fig. 5-4

Optimum clearing curve for splices

Fig. 5-5

Clearing curve for splices too wide

Fig. 5-6

Clearing curve for splices too narrow in the domain of thick places

Fig. 5-7

Clearing curve for splices too wide

Splices beyond the clearing curves (red dots) have to be repeated. The scatter plots show the population of the splices. Based on the scatter plot it is easy to recognize the outliers and to set the clearing curve for splices.

5.3 5.3.1

Splices Visual appearance

Splices are almost invisible in contrast to knots which used to be yarn ts in the past. Various investigations have shown that the strength of the splices is critical in order to obtain a suitable splice in of size, a compromise may need to be reached between splice strength and appearance. A well spliced t has a mass which is 20 to 30% higher than the yarn over a length of approximately 15 to 80 mm, and an average strength of around 80% of the mean yarn strength [1]. The variation of strength should also be low. Fig. 5-8 shows pictures of several splices.

USTER® QUANTUM 3

5.3

5

Splice Clearing

Fig. 5-8

5.3.2

Picture of several splices

Practical example

In a spinning mill the splices of 20 positions of a winding machine were tested. On each position, five splices were tested. The yarn type was Ne 30, carded, 100% cotton. Fig. 5-9 and Fig. 5-10 show the results of this trial. The blue dots indicate the test results of the splices, whereas the colored lines show the test results (minimum, maximum and average values) of the same yarn without a splice measured also on the USTER® ZWEIGLE SPLICE TESTER as the reference (ten measurements of the reference yarn). The minimum breaking force of the reference yarn was 222 cN, the average breaking force was 261 cN and the maximum breaking force was 302 cN. In regard to the elongation, the reference yarn had a minimum breaking elongation of 3.95%, an average breaking elongation of 4.66% and a maximum breaking elongation of 5.28% (Fig. 5-10). 400 350 300

Force [cN]

250 200 150 100 50 0 0

5

10

15

20

25

Force of splices

Fig. 5-9

5.4

30

35

40

45

Minimum Reference

50

55

60

65

70

Maximum Reference

75

80

85

90

95 100

Average Reference

Breaking force of splices, ring-spun yarn, compared with the mean strength of the yarn

USTER® QUANTUM 3

Splice Clearing

5

10 9 8

Elongation [%]

7 6 5 4 3 2 1 0 0

5

10

15

20

25

Elongation splice

Fig. 5-10

30

35

40

45

50

Minimum Reference

55

60

65

70

Maximum Reference

75

80

85

90

95 100

Average Reference

Breaking elongation of splices, ring-spun yarn

The numeric test results were as follows: Reference yarn

Splice

Ne 30, 100% CO, carded

Ne 30, 100% CO, carded

Strength [cN]

261

200

Variation of the strength [%]

9.91

23.0

Elongation [%]

4.66

4.87

Variation of the elongation [%]

10.16

16.88

Yarn type

Table 5-1

Out of this data, the following conclusions can be drawn. The splices only reach an average breaking force of 76% compared to the regular (reference) yarn. As a rule of thumb, the strength of a splice should reach at least 70% of the strength compared of a regular yarn. The breaking elongation, on the other hand, improved slightly. Regarding the variation of the strength and the variation of the elongation it can be observed that it is much higher compared to the reference yarn. This is an important quality parameter, as the high variation of the breaking force will lead to problems later on in subsequent processing. The lowermost breaking force of a splice was measured at 83 cN, and the strongest splice was measured with 295 cN. This is a huge difference that must be put under control. Therefore, it is recommended to check the splice mechanism of this winding machine and to modify the settings in order to reach higher strength values and lower variations from winding position to winding position.

USTER® QUANTUM 3

5.5

5

Splice Clearing

5.3.3

Basic principles of splicing

For a satisfactory splice, the two yarn ends have first to be prepared to make them properly tapered. Also, the fibers must be adequately separated and paralleled so that they are capable of intermingling when the splice is made. Fig. 5-11 illustrates the basic principle of the splicing process [1 and 2]: Time 1: Positioning of the yarns and cutting the unwanted yarn ends: The winding process was stopped in order to cut out the fault. The ends of the yarn are now parallel and face opposite directions. The scissors are ready to cut the unwanted yarn ends after the two yarns have been laid in place. Time 2: Conditioning the yarn ends: The clamps grasp the yarn at the appropriate places before the main splicing procedure begins. The free ends of the two yarns are sucked into end-conditioning nozzles and air blasts are provided to condition them before ing. Time 3: Forming loops to retract the yarn ends: Splicing is carried out after the two conditioned yarn ends are laid inside the splicing chamber so they are parallel, facing opposite directions and appropriately spaced without the tips of the conditioned ends protruding. The both lengths are drawn back until there is a certain length of overlap of the untwisted ends within the splicing chamber. Time 4: Splicing ends: A pulse of compressed air is injected through the nozzles into the chamber; the air blast intermingles the fibers and then causes the newly made t to rotate to produce false twist. Time 5: Removing spliced yarn. The yarn is then removed from the splicer and the winding process continues.

Fig. 5-11

5.6

Stages in splicing [2]

USTER® QUANTUM 3

Splice Clearing

5

Fig. 5-12 [1] shows the twist directions and twist distribution during the splicing operation. The splicing chamber in Fig. 5-12 (a) designed for use Z-twist yarns. The twist in the splice gives the t a similar appearance to that of the parent yarn and also strengthens the t.

When the splice occurs, the ends have to be in the proper relative positions. In order to avoid a thick splice, it is necessary to taper then ends to be spliced so that the t is not obvious. In Fig. 5-12 (b), the tapered ends are misplaced to give a thin spot. This is an undesirable weak spot. When the yarns overlapped two much, there would be a thick spot and two undesirable splice-tails (Fig. 5-12 (c)). These tails are mostly the subject of customer complaints during the knitting and weaving process. The splicer should be set to avoid these tails, sometimes at the expense of a slight loss in splice strength [2].

Fig. 5-12

5.3.4

Splice structure [2]

Wet Splicing

The USTER® QUANTUM 3 optical clearer can be used with wet splicer without any restrictions. The capacitive clearer can be used with restrictions depending on the amount of water sprayed. Please USTER® for . For the capacitive clearer the combination with Foreign Matter option, i.e. either C15/F30 or C20/F30, is required. There is a special setting for these clearers (Fig. 5-13) and the splice will be cleared optically and needs an optical setting.

USTER® QUANTUM 3

5.7

5

Splice Clearing

Fig. 5-13

5.4

Wet splice

Splice classification of the USTER® QUANTUM 3

The USTER® QUANTUM offers a unique feature, which is the splice classification. Each splice is measured, classified, and marked with a green or red square in the scatter plot depending on the splice settings. Thus, it is possible to check every winding position of a winding machine in order to see if the splices fulfill the requirements with regard to the appearance (Fig. 5-14).

Fig. 5-14

Display of splices (left) and splice classification (right)

Meaning of the red rectangles: The size of the splice or mass increase has exceeded the set splice limits. The splice formation has to be repeated. The USTER® QUANTUM 3 classifies the thickest (Jp) and thinnest (Jm) event for every splice.

5.8

USTER® QUANTUM 3

Splice Clearing

5

The splice channel J checks the yarn t when ing the clearer just after it has been made by the splicer device. The evaluation of J is similar to the NSLT thick and thin places evaluations. Splice check Jp /Jm detects yarn ts which are “too thick” or “too thin”.

5.5 5.5.1

Clearing limits for splice clearing (Jp and Jm) Standard way of optimizing clearing limits: Manual clearing limits entry

Fig. 5-15 shows the clearing limit as shown in the setting window of the Control Clearing Unit. The USTER® QUANTUM 3 allows the determination of the splice clearing limits by placing a maximum of 8 set points Jp1 to Jp8 /Jm1 to Jm8. In Fig. 5-15, we can see 5 setting points (red rectangle) and the clearing limit for splices. By this setting method the effects of a change of the parameters on the clearing limit can be demonstrated directly. As soon as we enter new values at set point, the next set point will appear until we reach the 8th set point. This means after we enter the values for Jp1 (or Jm1), set point Jp2 (or Jm2) will appear and it will continue the same way.

Fig. 5-15

Clearing limits on the screen of the Control Clearing Unit, manual entry

Set points have two parameters. These are: sensitivity (%) and reference length (cm).

Sensitivity The sensitivity (%) is a parameter for the clearing limits of the corresponding fault channel. The sensitivity setting shifts the clearing limit upwards (less sensitive) or downwards (more sensitive, Jp1 = 300%, Fig. 5-15).

USTER® QUANTUM 3

5.9

5

Splice Clearing

Reference length The reference length (cm) is a parameter for the clearing limits of the corresponding fault channel and shifts the clearing limit to the right (less sensitive) or to the left (more sensitive, Jp1 = 0.6 cm, Fig. 5-15).

5.5.2

Setting a smart clearing limit for splices (Jp/Jm)

With the USTER® QUANTUM 3 splice clearing became much easier. A smart possibility offered by the system is to synchronize the splice settings to the thick and thin place (NSLT) settings to avoid bad splices being ed. The splice clearing curve could be selected ideally as same as the NSLT clearing limits. Similar to the yarn body, after running only a few kilometers of yarn, the first impression of the scatter plot and the events will appear. In order to see the scatter plot, the should press the scatter plot key (Fig. 5-16). Besides the scatter plot, also the scatter plot of the cut faults and remaining events, and the number of expected fault cuts per 100 km together with the used setting limits will appear directly on the same setting page (Fig. 5-16). It is recommended to have at least 100 splices before making any fine tuning in the splice clearings settings.

Pressing

key presents

•

Scatter plot of the cut faults and remaining events.

•

Number of expected fault cuts / 100 km Clearing limit Red dots = cut yarn faults. Green dots = remaining events

Fig. 5-16

Jp settings adjustment to the scatter plot, thick places

For highest quality requirements the Jp, Jm setting can even be set up to 5 to 10% below the NSLT clearing limit (red circle). Good splices set the Jp splice clearing curve below the NSL thick places clearing curve (more sensitive setting) and on the contrary bad splices set the Jp splice clearing curve above the NSL thick places clearing curve (less sensitive setting, Fig. 5-16). The same rule is also valid for Jm splice clearing curve; there the Jm clearing curve will be set below or above the T thin places clearing curve according to the good or bad results. If this will result in too many Jp or Jm cuts then the rogue splicers should be identified and fixed. F and PP faults are also detected during splice check (Fig. 5-17).

5.10

USTER® QUANTUM 3

Splice Clearing

Fig. 5-17

5

Jm settings adjustment to the scatter plot, thin places

Splices are displayed together with all the other yarn faults of the machine, of a group or of a winding position. It can be switched from absolute values to values per 100 km.

Fig. 5-18

Jp/Jm yarn fault classification per winding position

USTER® QUANTUM 3

5.11

5

Splice Clearing

Recommendations: The new setting possibilities will help to ensure that the splice should always be better than the removed yarn fault. Depending on the mechanical settings of the splicer, we recommend to start with the splice adjusted to the thick place (NSL) and thin place (T) limits. For high quality requirements we also can use a setting closer than the clearing limits. This depends on the accepted Jp/Jm cut level / 100 km and of course of the splice quality possible. Splices are displayed together with all the other yarn faults of the machine, of a group or of a winding position (Fig. 5-19, red rectangle). In Fig. 5-19, the splice failure ratio (JR) has also been shown (Blue rectangle). Splice failure ratio (JR) measures the number of cut ts compared to the ed ones. It is the relation between total splices and splice cuts (Jp+Jm). In this example, the splice failure ratio is equal to 3.4.

Fig. 5-19

Jp/Jm yarn fault registration

In order to find rogue splicers, the should check the machine summary report to find the bad splicer. In the following example it is winding position no. 9 with a splice failure ratio of 33.3%. The mean value is 12.44% (Fig. 5-20).

5.12

USTER® QUANTUM 3

Splice Clearing

Fig. 5-20

5.6

5

Machine summary display /JR Splice failure ratio

Upper yarn detection (U)

The “upper yarn” feature avoids that a double threat is accidentally taken from the package above the clearer (Please consult Chapter 11). Settings (Fig. 5-21): For capacitive clearers:

80%

For optical clearers:

60%

Fig. 5-21

Upper yarn detection (U)

USTER® QUANTUM 3

5.13

5

Splice Clearing

5.7 5.7.1

Minimizing the number of splices Critical items which affect the number of splices

The number of splices depends on the selected number of cuts to eliminate disturbing faults and the number of ts necessary to process bobbins into a cone. There are experience values available for yarn clearers on winding machines to understand the replacement of disturbing faults by splices. The relationship between the bobbin size, the number of cuts and the yarn count is explained in Fig. 5-22. This figure shows the number of splices required if the yarn clearer cuts 20 disturbing thick and thin places, 20 colored foreign fibers and 2 polypropylene fibers. No. of splices per 100 km 140 92g

120

100 57g 80

40g

60

Bobbin changes Polypropylene fibers

40

Colored foreign fibers 20 Disturbing thick and thin places “Natural end breaks”

0 6 100

Fig. 5-22

12 50

20 30

30 20

60 10

120 Nec 5 tex

Number of splices for a given number of cuts

The average yarn mass of a fine yarn bobbin is 40 g. The mass of a bobbin in the medium count range is approximately 57 g and 92 g within the coarse count range. Fig. 5-22 shows that the number of splices required per 100 km also depends on the count and the weight of the bobbin. As already mentioned, the disturbing yarn faults have to be eliminated on the winding machine and replaced by a splice. The splice, however, should no longer be disturbing for the human eye. Therefore, the splice can be checked by the yarn clearer (Fig. 23) and should be below the clearing curve.

5.14

USTER® QUANTUM 3

5

Splice Clearing

Fig. 23

5.7.2

®

Monitoring of splices with the USTER QUANTUM 3

Mean time between two splices

It is not only the number of splices which needs our attention, but also the mean time between two splices. If we are not careful in selecting the optimum clearing curve, the efficiency of the winding machine may collapse. Table 5-2 shows the conditions on a winding machine when processing a 100% cotton yarn, Nec 30, carded, winding speed 1400 m/min. Figures per 100 km of yarn. Bobbin changes

20

‘Natural’ end breaks

2

Thin and thick places

21

Colored foreign fibers

18

Polypropylene fibers

2

Total number of splices

63

Mean time between 2 splices per winding position

1.13 min

Table 5-2 Mean time between two splices

The total run time of the machine to produce a yarn length of 100 km is 71.4 min at a winding speed of 1400 m. With a total number of 63 splices, the mean time between 2 splices is only 1.13 minutes. With a higher number of cuts, the mean time between splices would drop below one minute. This, however, can be considered as a critical limit. Therefore, it is beneficial for the mill to select the clearing curves carefully for disturbing thick places, thin places and foreign fibers.

USTER® QUANTUM 3

5.15

5

Splice Clearing

5.7.3

Field test

The USTER® QUANTUM 3 has to fulfill more and more tasks. On one hand the spinning mill has to eliminate disturbing thin places, thick places, colored foreign fibers and polypropylene fibers and has to replace them by a splice. In addition, the splicer of the winding machine has to produce splices at the end of each bobbin. On the other hand the clearer should not influence the efficiency of the winding machine too much. The following is a study to demonstrate the critical cut rates of a clearer by means of the mean time between splices MTBS.

Conditions: Yarn Ne 30 (20 tex), yarn weight per bobbin 57 g, yarn length per bobbin 2850 m Winding speeds: 800 / 1000 / 1200 / 1400 / 1600 m/min Number of splices according to Table 5-3. Reasons for splices

Conditions 1

2

3

4

5

6

7

8

Bobbin changes

34

34

34

34

34

34

34

34

"Natural" end breaks

4

4

4

4

4

4

4

4

Thick and thin places

10

20

30

40

50

60

70

80

Colored foreign fibers

10

20

30

40

50

60

70

80


5

5

5

5

5

5

5

5

Number of splices

63

83

103

133

153

173

193

213

Table 5-3

Number of splices, conditions 1 to 8

Winding speed

Winding time 1

2

3

4

5

6

7

8

800 m/min

125 min/100 km

2.08

1.51

1.21

0.94

0.82

0.72

0.65

0.59

1000 m/min

100 min/100 km

1.59

1.20

0.97

0.75

0.65

0.58

0.52

0.47

1200 m/min

83 min/100 km

1.32

1.00

0.81

0.62

0.54

0.48

0.43

0.39

1400 m/min

71.4 min/100 km

1.13

0.86

0.69

0.54

0.47

0.41

0.37

0.34

1600 m/min

62.5 min/100 km

0.99

0.75

0.61

0.47

0.41

0.36

0.32

0.29

Table 5-4

5.16

Mean time between splices MTBS (under the conditions mentioned above)

Mean time between splices MTBS at conditions 1 to 8

USTER® QUANTUM 3

Splice Clearing

Fig. 5-24

5

Mean time between splices

Reading example, Fig. 5-24: At condition 2 the mean time between splices already drops below 1 minute if the yarn speed exceeds 1200 m/min.

5.7.4

Relationship between the productivity on winding machines and splices

The adjustment of the clearing limits is not only improving the quality level of the yarn. But in all cases the clearer should only remove the disturbing faults. The result is: optimum quality with less number of cuts and splices. By only making the right cuts one can optimize quality and productivity. It has been proven that the performance of the clearer (amount of cuts) is responsible for changing drastically the winding machine productivity. In Fig. 5-25, the relationship between the productivity on winding machines and splices can be seen. The red line is for yarn count Nec 50 and the blue line is for yarn count Nec 30. Fig. 5-25 shows that 70 splices per 100 km means a productivity level of 79% for yarn count Nec 30 and a productivity level of 81% for yarn count Nec 50. Speed: 1400 m/min.

USTER® QUANTUM 3

5.17

5

Splice Clearing

Table 5-5 shows an example of a winding productivity calculation. Winding speed [m/min]

Count [tex]

Bobbin weight [g]

Fault cuts [1/100km]

Bobbin changes [1/100km]

Winding time for 100 km without splices [min]

Formation of a splice [min]

Bobbin change duration [min]

Total duration for fault elimination [min]

Total duration for bobbin changes [min]

Total duration for stops [m]

Winding efficiency [%]

1400

12 tex (Ne 50)

60

20

20

71,43

0,18

0,22

3,6

4,40

8,0

88,8

1400

12 tex (Ne 50)

60

70

20

71,43

0,18

0,22

12,6

4,40

17,0

76,2

1400

20 tex (Ne 30)

60

20

33,3

71,43

0,18

0,22

3,6

7,33

10,9

84,7

1400

20 tex (Ne 30)

60

70

33,3

71,43

0,18

0,22

12,6

7,33

19,9

72,1

Table 5-5

Example of a winding productivity calculation

Fig. 5-25 is a graphical evaluation of Table 5-5.

Fig. 5-25

5.18

Relationship between yarn clearing and productivity: splices and winding machine efficiency

USTER® QUANTUM 3


6


6.1

Introduction

6

Periodic yarn faults are thick places, which always occur with the same distance to each other. Such faults are caused in the spinning process, when yarn guiding elements are defective. An eccentric front roller of the ring spinning machine leads to a periodic fault with a wavelength of 8 cm, because the diameter of these rollers are 1 inch or 2,54 cm, and such a roller always causes faulty drafts in the draw-box within the same time intervals. The size of each individual fault is mostly not disturbing. But as a series of yarn faults, they can very well be disturbing. Disturbing patterns on a taper board due to periodic yarn faults can be seen in Fig. 6-1.

Fig. 6-1

Periodic fault in cotton yarn resulting in a moiré pattern

The USTER® QUANTUM 3 has a new periodic faults channel (PF), and with minimal settings and by using only two parameters, the system can determine periodic faults of all wavelengths in parallel.

Fig. 6-2

®

New periodic fault channel (PF) of the USTER QUANTUM 3

USTER® QUANTUM 3

6.1

6


6.2

Influence of the yarn speed on the winding machine

On an automatic winding machine, the yarn speed is not constant. The yarn speed depends on the position of the yarn during the reversal movement on the drum. Therefore, the yarn signal of a strictly periodic yarn fault does not appear as a strictly period fault in a spectrogram (Fig. 6-3), but it also influences some adjacent lines. In order to detect such kind of periodic faults in bobbins on winding machines a new feature was introduced, called PF (Periodic Fault). Bobbins with periodic mass variations have to be ejected by the winding machine, because such faults are present throughout the entire bobbin. Fig. 6-3 shows graphically the difference of a strictly periodic fault in a spectrogram if the speed is not constant.

Strictly-periodic faults detected by the yarn clearer if the yarn speed is constant

Same faults detected by the yarn clearer because the yarn speed on the winder is not constant

Fig. 6-3

Difference between strictly-periodic faults at constant speed and variable speed

There is a more intensive effect of the drum on the variation of the periodicities in the short wavelength range.

6.3

Further reasons for periodic defects

In most cases, disturbing periodic faults are formed at the ring-spinning machine. Widely known are defects caused by cuts and pressure marks on the front rollers. By this, the continuous distribution of the fibers is disturbed, which results in thin and thick places. The size of the fault corresponds to an alteration/shift of all fibers of about 30 – 50%. The fault length depends on the dimension of the defective machine part. The distance between the single events corresponds to the circumference of the roller.

6.2

USTER® QUANTUM 3


6

If a spinning position or the whole spinning frame is stopped and the pressure is not taken from the top roller, it can lead to pressure marks on the top rollers after longer stops and thus to periodic defects in the yarn. The distance between the single events corresponds to the circumference of the rollers. Defective aprons of the drawbox also result in periodic yarn faults. For regular ring spun yarns, the reasons are mostly pure mechanical problems, which lead to periodic faults in the yarn. For compact yarns, the reasons can be found in the contamination with fibers and dirt. This dirt can build up for an uncertain time, which makes it much more difficult to find the reasons. Therefore, the monitoring of periodic defects in compact yarns is essential.

6.4

Periodic fault registration with the PF

Periodic yarn defects cannot be detected with the normal settings of a yarn clearer, as the size of each individual fault lies far below the adequate clearing limits. With the USTER® QUANTUM 3 such periods can be detected with the Periodic Fault (PF) channel. This periodic fault option (PF) allows a quick and easy way of setting, and the system can scan the yarn for periodic faults of all wavelengths simultaneously.

6.4.1

Setting for Periodic Faults (PF / Optional Q Data)

The periodic yarn faults always occur with the same distance from each other as already mentioned. The thick places which are created by the periodic alteration of the fibers in the cross-section, serve as the threshold in the PF-option. The recommended setting for FP (Periodic Faults) is: •

Period regularity:

75%

•

Number of periods:

30

•

PF-Alarm:

3 per 1 km

For long periods (< 1 m) it is also possible to set 90% regularity and 15 events. After reaching the given number of faults ("number of periods"), a cut follows or a PF-alarm is triggered.

USTER® QUANTUM 3

6.3

6


Fig. 6-4

PF settings for detecting periodic defects

Fig. 6-5

Disturbing defects (so-called periodic defects)

When the value of the period regularity is 100%, then the channel will detect only strictly periodic yarn faults after a certain distance (Fig. 6-5). A setting of 100% means the periodicity is absolute. However, on the winding machine a defect is never strictly periodic as already mentioned due to the varying yarn speed.

Fig. 6-6

6.4

PF settings for detecting periodic defects

USTER® QUANTUM 3


6

The checking of the settings is only possible with a defective yarn. There is also the option to choose a very sensitive setting, in order to make corrections according to the results. This is only possible with the sensitivity settings. For fault free yarn set 30 events and adjust the regularity until you get ∼0,1 … 0,2 cuts/100 km Furthermore, it is recommended to produce a taper board with the defective yarn for a visual evaluation of the defect.

Fig. 6-7

Taper board / Periodic fault on the left hand side

The detection of periodic yarn faults is displayed together with all the other yarn faults of the machine, a group or a winding position. All cuts and alarms are displayed in absolute and relative values.

Fig. 6-8

PF yarn fault report with PF faults

USTER® QUANTUM 3

6.5

6 6.5


The effect of periodic faults on the fabric appearance

Mix-up of reference yarn with a yarn having periodic mass variation Periodic mass variations in the yarn result in disturbing patterns in woven and knitted fabric. They are never caused by the raw material, but are due to faults during fiber processing. Such faults must be detected as early as possible. This type of fault is, however, extremely common. Mechanical parts such as defective card clothing, eccentric rollers of drawing elements, defective aprons, etc., can all produce periodic mass variations. Thick or thin places can appear at regular intervals in woven and knitted fabrics according to the width of the woven or knitted material and according to the wavelength of the periodic fault. These thick or thin places result in unacceptable patterning and, in most of the cases, downgrade the finished fabric. Fig. 6-9 shows two possible fault patterns and one optimum distribution in a woven or knitted material caused by periodic mass variations.

Moiré Fig. 6-9

Stripiness

Optimum distribution

Fault patterns

The fault pattern referred to as moiré is the most frequent, whereas the pattern on the right hand side is an exceptional case. Nearly all periodic faults result in an uneven appearance in the finished fabric. The type of disturbance, whether it is in a woven or knitted fabric, depends mainly on the wave-length λ of the fault. In this respect one differentiates between short, medium and long-term periodic mass variations.

Another example of a yarn with periodic faults: The condition of the rollers and the degree of ageing of the rollers affect the spinning performance. Occasionally, cotton fiber producers suffer from infestations of aphids and other insects, which eventually produce contaminations such as sugars (honeydew) on cottons. Cotton fibers become sticky and difficult to handle during processing due to these contaminations and cause fiber lapping problem during processing [2]. Carelessness in cleaning lapped fibers on the rollers, especially during the cleaning process when metal knives are used, can cause defects which leads to high unevenness. The result will be an uneven fabric appearance. In our example, we have knitted ten rows of reference yarn and ten rows of a yarn spun using defective top rollers to produce a periodic fault. There is a significant difference between the CVm values, the thin places, thick places and neps values of the two yarns (Table 6-1). When we compare the USTER® STATISTICS values of the two yarns; the CVm value of the reference yarn is equivalent to 61% of the USTER® STATISTICS, the CVm value of the defective yarn is more than 95% of the USTER® STATISTICS. There is also a significant difference between the USTER® STATISTICS values of thin places, thick places and neps of the two yarns.

6.6

USTER® QUANTUM 3


Reference

Yarn Count (Ne)

Twist 1/m

Twist direction

CVm %

Thin -50%

Thick +50%

30

830

Z

12.7

0.5

61

29

17.5

118

>95

>95

USP07 Fault

30

830

USP07

Table 6-1

Z

Neps +200%

H

34.5

66

4.6

71

73

22

1030

151

4.7

>95

>95

30

2DØ mm 0.22

CV 2D% (8mm) 9.6

6

D (abs) 3 g/cm 0.5 18

0.22

13.1

0.5 28


The result of the defective top roller can also be seen as red peaks in the mass spectrogram (Fig. 6-11) and periodicities in the conical taper simulation (Fig. 6-1). Because of the periodicities in the defective yarn, thick places can be observed as dark-colored, periodic areas in the grey and the dyed samples Fig. 6-12 and Fig. 6-13). Fig. 6-10 shows the spectrograms of the reference yarn.

Fig. 6-10

Fig. 6-11

®

Spectrogram of the reference yarn measured with the USTER TESTER

®

Spectrogram of the defective yarn (defective top rollers) measured with the USTER TESTER

USTER® QUANTUM 3

6.7

6


Fig. 6-12

Reference fabric

Fig. 6-13

Defective fabric (defective top rollers)

Periodic thick places have more fibers in the cross-section and absorb more dyestuff. Therefore, such thick places appear darker in the fabric.

6.5.1

Reasons and measures to minimize periodic mass variations

In Table 6-2 and Table 6-3, the origin of the faults related to periodic mass variations is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. PERIODIC MASS VARIATIONS Origin of Faults

Possible Reasons

Comber, Drawframe,

Incorrect setting of the piecing process (Comber)

Roving frame,

Eccentricity or defects of front top rollers

Ring spinning frame

Eccentric or defects front bottom rollers Contaminated front rollers (honeydew, etc)

Table 6-2

6.8

USTER® QUANTUM 3


6

®

PERIODIC MASS VARIATIONS / USTER Tools for Improvement Tools

Improvement ®

Systematic Quality Control with the USTER TESTER

®

Use “Periodic Faults” option to separate bobbins with periodic mass variations

USTER Testing off-line USTER QUANTUM CLEARER

®

Monitor bobbins with periodic faults with the quality data software ®



Preventive measures and tools for the management of periodic mass variations

USTER® QUANTUM 3

6.9

6

6.10


USTER® QUANTUM 3


7.


7.1

Introduction

7

In the previous chapters we have dealt with seldom-occurring yarn faults which can be eliminated and replaced by a splice. This chapter deals with frequent yarn faults which cannot be replaced by a splice anymore. If frequent yarn faults exceed preset quality limits, the bobbin has to be ejected by the winding machine. Such yarns, if wound on a cone, would affect fabrics significantly (“cloudy appearance”, to many thick places, thin places and neps, high hairiness, etc.).

Fig. 7-1

Frequent yarn faults and seldom-occurring yarn faults

Fig. 7-2

Disturbing yarn faults were discussed in chapters 3 to 6. This chapter deals with frequent yarn faults.

In order to meet the increasing quality requirements for the products and to cope with the high production costs, yarn manufacturers have to optimize the individual production stages at shorter intervals today. With the optimization, it is important to fulfill the quality requirements of the customers completely and reliably. The reaction time for an optimization or the adjustments is an important factor. Any quality which is higher than actually required will result in an unnecessary increase of the manufacturing costs. Off-quality, however, leads to significant quality costs and to a loss of customers. Uncompromising quality management in all production stages guarantees a constant quality of the product and, at the same time, a cost optimization. In order to react immediately to changes of the yarn quality, it is important to monitor the quality parameters during the production.

USTER® QUANTUM 3

7.1

7


The determination of the frequent yarn faults is an option of the USTER® QUANTUM 3 and consists of: •

yarn evenness (CV)

•

imperfections (frequent thick places, thin places and neps)

•

class alarm

•

hairiness

Fig. 7-3

Overview of quality characteristics

The values of the yarn evenness, of the hairiness and of the imperfections are important information about the quality of a yarn. Through their results, it is possible to control the complete course of production. The analysis of the single value makes it possible to carry out countermeasures without any time delay. The following differences between the off-line measurement (laboratory) and the on-line measurement (production) must be considered:

Off-line measurement •

The main purpose of the off-line measurement is the correct determination of the quality parameters.

•

The results are reproducible, as the measurement is always carried out under the same conditions, i.e. a standard climate, the same sensor, and with the same testing speeds.

•

The results can be used for comparison purposes, like e.g. the USTER® STATISTICS.

•

The results are based on random samples.

7.2

USTER® QUANTUM 3


7

On-line measurement •

The main purpose of the on-line measurement is a 100% monitoring of the yarn and its quality parameters.

•

The results are determined at different speeds.

•

The measurements are carried out with different sensors (measuring field width, capacitive or optical).

•

The measurements are carried out on different machines. The environmental conditions such as climate, yarn course, dust, fly, and temperature are not constant in the winding room.

•

If limits are exceeded, actions can be taken in order to remove the faulty yarn from the production process.

The on-line monitoring of quality parameters cannot replace the off-line measurement, because different requirements have to be fulfilled. This makes it clear, that the absolute values of the on-line measurement cannot be compared exactly with those of the off-line measurement. However, the on-line measured deviations from the nominal value match within certain tolerances with the measurements of the off-line tests. With the USTER® QUANTUM 3 all the features of a yarn, which determine its quality, can be measured individually. This delivers detailed information. Besides the values of the yarn evenness, the hairiness and the imperfections have to be taken into . Practical tests have shown clearly, that with a careful decision regarding the setting of alarms and the consequent tracking of fault reasons, the quality level can be kept within narrow limits, and this can be realized without excessive costs. In the following, different possibilities for the monitoring of the yarn structure are described. The setting of the alarms of the different monitoring possibilities must also be carried out. This is described in chapter 7.6.

7.2

Yarn evenness

The coefficient of variation CV is a well-known value for the determination of the evenness of slivers, rovings and yarns. Each process in a spinning mill contributes a part to the unevenness. The continuous determination of the quality parameters guarantees that all spinning positions produce the same quality. For the calculation of the yarn evenness CV, it is possible to select 2 measurements: •

Continuous, over the whole bobbin length with selectable reference lengths or

•

Starting from a bobbin change with selectable reference lengths

When a preset limit is exceeded, the system can provide an alarm for the respective winding position and another one for the mean value of a quality parameter derived from all winding positions.

USTER® QUANTUM 3

7.3

7


7.2.1

Definition of the coefficient of variation CV

The coefficient of variation is given in percent; it is a measure of the yarn unevenness and is defined as follows:

CV =

s × 100 % x

Mass/ diameter

+s

_

-s

x Length

Fig. 7-4

Graphical representation of the CV

With the help of the coefficient of variation, CVm as well as CVd, winding positions which deviate with respect to quality, can be monitored. CVm = Coefficient of variation based on the measurement of the yarn mass (capacitive sensor) CVd = Coefficient of variation based on the yarn diameter (optical sensor)

7.2.2

Reasons and effects of the yarn irregularity

The reason for yarn irregularity is based on the fact that it is not possible for staple fiber yarns to keep a constant number of fibers in the cross-section. Reasons can be divided into: •

raw-material related faults, like e.g. the variation of the fiber length, fiber adhesion, short fiber content, stickiness

•

process-related faults, caused by defective machine parts, like draw-box defects or the kind of roller coats

From these points it can be derived that the coefficient of variation is used as an efficient method for quality and process monitoring. In general it can be said: the lower the CV-value, the more even is the material and the more even it will look in the end-product. It is known, that the evenness is not constant over the whole bobbin length. It usually decreases from the tip to the base of a bobbin. This circumstance has to be taken into when evaluating the setting of the alarm limits.

7.4

USTER® QUANTUM 3

7


Fig. 7-5 to Fig. 7-7 show a mercerized cotton T-shirt. In the zoomed pictures (Fig. 7-6, Fig. 7-7) we can observe an uneven appearance of the knitted fabric because of thin places and thick places even though it is an expensive mercerized T-shirt.

Fig. 7-5

High unevenness / mercerized / 100% cotton, combed, Nec 50

Fig. 7-6

7.2.3

High unevenness / mercerized cotton

Fig. 7-7

High unevenness / mercerized cotton, magnified

Deviation of the CV mean value of a group of clearers (CV–MV)

The CV mean value of the group (CV-MV) is determined from all winding positions. As it is based on a large population, it does not show any erratic deviations. Erratic deviations can occur with individual winding positions. The upper alarm limit “CV-MV upper” and the lower alarm limit “CV-MV lower” can be set independent of each other. Compared to the CV of the winding position, this "alarm band" is set to a relatively high sensitivity because a mean value CV-MV which exceeds preset limits is usually an indication of serious problems (Fig. 7-8). The CV-MV indicates important changes and trends of the yarn. In an initial test cycle, the settings of this alarm band should not be selected too sensitive. After the CV mean value of the group has been determined over a certain time span (e.g. one shift or several doffings), then the upper and lower alarm limits can be set.

USTER® QUANTUM 3

7.5

7


If the upper or lower alarm limits are exceeded, then this will be indicated by an alarm. After a period of observation, the setting can then be adjusted according to the specific application. This is illustrated by Fig. 7-8.

Fig. 7-8

7.2.4

Schematic representation of the deviation behavior of the CV mean value of the group

Deviation of the CV of a single winding position (CV-SP)

The mean of the CV of an entire machine (CV-MV) is used as a reference for the CV value of a single winding position. The monitoring of the CV of the spinning position is carried out in relation to the current CV mean value of the machine. As with the CV-MV, an "alarm band" can be set for the CV-SP value. The set value is effective in both the positive and the negative direction. If an alarm limit is exceeded, then this will be indicated by an alarm. Depending on the settings, the winding position can be blocked.

Example: The percentage deviation (CV-SP), which is defined as the alarm limit, is calculated by means of the CV-MW, as shown in the following example, Fig. 7-9: With a CV-MV of 14% and an alarm limit of ± 20%, the effective range is between 11.2% and 16.8%. The deviation behavior of the CV of the single winding position is shown schematically in Fig. 7-9.

Fig. 7-9

7.6

Schematic representation of the deviation behavior of the CV of an individual winding position

USTER® QUANTUM 3


7.2.5

7

Settings

In the window "Q-Parameter" of the Control Unit, the following settings can be adjusted:

Fig. 7-10

Setting window for the coefficient of variation at the Control Unit

Reference length: It is possible to set the reference length between 50 – 10'000 m. In winding, a reference length of 100 m has been accepted as the standard. This is a length which is necessary for a reliable CV-value. However, the setting of the reference length also depends on the objective when monitoring the coefficient of variation. •

For data acquisition: For the monitoring of the CV it is recommended to select the reference length of 100 m starting from the bobbin tip (see "measurement"). As the yarn evenness increases from bobbin tip to bobbin base, it is guaranteed that results measured under the same circumstances (same yarn length) can better be compared with each other. A longer reference length is not recommended as the number of faults increases at the bottom part of the bobbin and thus, the CV-value is influenced. For pure data collection, no action is taken in case of exceeding limits.

•

For the selection of bad bobbins: The selection of the reference length depends on the quality requirements. The reference length must be derived from the possible CV-deviation in the yarn. The monitoring of faulty yarn must be carried out continuously. This guarantees that bobbins which do not meet the quality requirements will be monitored and can be taken out of the winding process (action: block). Mainly in the production of compact yarns, faults which are formed in the compacting zone can influence the CVvalue. Such faults can occur over the whole bobbin length.

USTER® QUANTUM 3

7.7

7


Measurement: The measurement can be carried out: •

continuously

•

at bobbin change

The following winding machines provide a bobbin change signal. This means that the winding position informs the clearer when a bobbin change is carried out: •

Murata Process Coner PC 21

•

Schlafhorst Autoconer 338

•

Savio Orion

•

Schlafhorst Autoconer AC5, ACX 5

•

Savio Polar

Alarm limit MV-monitoring This is an absolute monitoring of the CV of a group. The CV mean value (CV-MV) alarm can only be deleted by increasing the alarm limits or when the CV-MV decreases below the alarm limit. As no action is carried out in case of an exceeding limit, the alarm must be considered as a warning. If the alarm limit is set to 0, the monitoring is inactive.

Monitoring of individual winding positions With the monitoring of the CV of a winding position, a relative deviation of the single bobbin (SP-MV) from the mean (CV-MV) is set. The setting of the percent value must be determined for each individual application. Due to the diverse causes for the changes of the yarn evenness, it is not possible to give any recommendations for the settings. •

The setting of an upper CV alarm limit which serves for the monitoring and detection of: -

•

a high CV, caused by diverse faults in the production process a rough ring slow spindles caused by loose or contaminated drive belts or spindles drive belts

The setting of a lower CV alarm limit serves for monitoring and the detection of yarns, which have too much twist caused by: -

heavy ring travellers 2 ring travellers on one ring with different operating hours, i.e. the old traveller was not removed twisted drive belts for spindles

If the yarn evenness of a bobbin deviates from the spindle ALARM LIMIT, a CVp- or CVm alarm is triggered. At the same time, this deviation from the mean value can be found on the window for "textile alarms" at the control unit. If the information on the yarn evenness is desired only, there is the possibility to set the alarm limit, but without selecting any actions. In this case, the number of alarms is indicated in the shift report. If the alarm limit is set to 0, the monitoring of the alarms is inactive.

7.8

USTER® QUANTUM 3


7

Action If the unevenness CV of a winding position exceeds the upper or lower alarm limits, the sensor reacts according to the selected alarm, setting column ACTION. An entry is made in the logbook in all cases. There are four different possibilities: •

•

cut

•

block

•

block +suck

If the action “” is chosen, the measurement with a set limit serves only for data collection to monitor the quality of the production. There will be no reaction on the winding position. The alarm will be counted as Q Registration. If USTER® QUANTUM EXPERT for winding is connected; the signal is transferred to this data system for alarm purposes. With the selection cut, a cut is triggered when a preset alarm limit is reached. The sensor will cut and the alarm will be counted as a Q Cut. The faulty yarn will be removed from the cone with the maximum possible length of the winding position. The action block can be recommended, if it is desired to take a bad bobbin out of the process. The winding position will be blocked and the sensor lamp lights up. The alarm will be counted as Q Blocking. The behavior of the winding position depends on the machine type. For this, trained personnel are necessary. Depending on the machine type, an automatic bobbin change is carried out or the bobbin must be changed manually. The action block + suck can be recommended, if it is desired to take a bad bobbin out of the process. The winding position will be blocked and the sensor lamp lights up. The alarm will be counted as Q Blocking. The Reference length or evaluation length of the quality parameters CV, H or IP has a fixed maximum length of 64 m if the action at alarm is set to "block + suck". After the blocked winding position has been reset, 64 m yarn will be sucked off from the cone.

7.2.6

Display of the CV values

Fig. 7-11 shows the results of the CV-measurement of each winding position as well as the CV-mean value of the group and the absolute CV-alarm at the control unit.

USTER® QUANTUM 3

7.9

7


Fig. 7-11

Display of the CV-value

•

SP UPPER LIMIT The upper absolute CV-limit is calculated from the CV-mean value of the group and the set relative upper CV-alarm limit.

•

SP LOWER LIMIT The lower absolute CV-limit is calculated from the CV-mean value of the group and the set relative lower CV-alarm limit.

If the CV of a winding position lies above or below the absolute SP ALARM LIMIT, a CVp- or CVmalarm is triggered.

7.3

Imperfections

"Imperfections" are frequent thick and thin places as well as neps, which are formed when processing fibers into yarns. They can be raw material related as well as process related. The frequency and the size of imperfections influence considerably the further processing and the quality of a yarn and thus the textile fabric. The frequency and the size of these events can provide information about the quality of a produced yarn. Furthermore, the data serve for monitoring and the optimization of the processes in spinning preparation. Fig. 7-12 shows a T-shirt with a high number of thick places, thin places and neps under reflective and transmitting light. It shows the irregularity caused by imperfections on the surface of the garment. The reflective light shows particularly the amount of neps. The same garment shows particularly the effect of the short thick places and thin places on the appearance of the fabric in transmitting light.

7.10

USTER® QUANTUM 3


Fig. 7-12

7.3.1

Garment

Reflective light

7

Transmitting light

Definition of imperfections

Imperfections are divided in three fault groups and four classes. This can be seen in Table 7-1. Fault group

Class

Neps

shorter than 4 mm

140%

200%

280%

400%

Thick place

length: about fiber length

35%

50%

70%

100%

Thin place

length: about fiber length

-30%

-40%

-50%

-60%

Table 7-1

Imperfections, fault groups and classes

Thick and thin places Thick and thin places have a relationship to the yarn evenness. The size and frequency of thick and thin places has an influence on the yarn evenness. The higher the unevenness, the more frequent the occurrence of thick and thin places. An increase of the number of thick and thin places affects the quality of a yarn and has a disturbing effect on the textile fabric. At the same time the increase is a textile-technological indicator for a deteriorating raw material quality, for worn-out card clothing in spinning preparation and worn-out key components of the spinning machine. If such an increase occurs, the spinner can optimize the spinning preparation based on these data. The occurrence of thick and thin places can of course not be prevented, but it is possible to reduce the frequency and size of these faults.

USTER® QUANTUM 3

7.11

7


Neps Neps have an enormous influence on the appearance of a textile fabric. Neps are defined as follows: "Dense tangle of intertwined fibers with a core of fibers or with seeds or seed coat fragment slightly enclosed in fibers. Usually spherical. Diameter approximately 1 mm." We differentiate between raw material-related and process-related neps.

Raw material-related neps Raw material-related neps which usually consist of dead and immature fibers often cause problems due to different dye absorption in the dyeing process. Nep, enlarged 44fold

Fig. 7-13

Nep, enlarged 360fold

Nep in a knitted fabric, scanning electron microscope photography

Fig. 7-13 shows an enlarged image of a knitted fabric made with a scanning electron microscope. It shows the effect of these so-called shiny neps. The neps, which in part consist of dead and immature fibers, have not absorbed any dyestuff at all. They remain in the fabric as small white spots. Seedcoat fragments, which also contain fibers, are also known as raw-material related neps.

Process-related neps Process-related neps are actually produced in the opening/cleaning lines and in spinning preparation. Due to the fact that cotton is being cleaned at very high speeds, this also results in a loss of quality. The consequences of higher cleaning speeds are a higher content of short fibers and neps. The initial increase of the number of neps occurs already during the ginning process, and additional neps are produced in the cleaning lines of the spinning mills. Carding may result in a significant reduction in the number of neps but, depending on the condition of the clothing, it also produces new neps. The effect of an increased number of neps is becoming noticeable especially in fine knitted or woven fabrics. An increased number of neps also causes problems while processing fabrics in the knitting mill (breaking of needles, loops are not properly taken up, formation of holes).

7.12

USTER® QUANTUM 3


7.3.2

7

Settings

The determination of the alarm limits requires some basic knowledge of statistics first, the mean value of the number of imperfections over at least 10 producing winding positions has to be determined. The mean value indicates the arithmetic mean of the single values. It is the sum of all single values, divided by the number of the single values. The standard deviation is the variation of single values and can be calculated according to the rules of statistics. The standard deviation, therefore, is used for setting the alarm limits.

Recommendation for the alarm limits of the imperfections: An insensitive setting is: Mean value (MV) of the imperfection classes + 5 × standard deviation (s). A sensitive setting is: Mean value (MV) of the imperfection classes + 3 × standard deviation (s).

Fig. 7-14

Setting of the alarm limits for imperfections

Evaluation length Setting: 100 m to 2000 m. After this length the alarm condition is checked and a new measurement started. It is recommended to select an evaluation length of 1000 m.

Neps The limit for neps of all classes can be set between 0 – 64000. If 0 is selected, the monitoring is inactive. For neps, the operator can select between several sensitivity levels.

USTER® QUANTUM 3

7.13

7


Thick places The limit for thick places can be set between 0 – 64000. If 0 is selected, the monitoring is inactive. For thick places, the operator can select between several sensitivity levels.

Thin places The limit for thin places can be set between 0 – 64000. If 0 is selected, the monitoring is inactive. For thin places, the operator can select between several sensitivity levels.

Action If the class limit is reached on a winding position, the sensor reacts according to the setting ACTION at the ALARM window. An entry is made in the logbook in all cases. There are four possibilities: •

•

cut

•

block

•

block +suck

If the action “” is chosen, the measurement with a set limit serves only for data collection to monitor the quality of the production. There will be no reaction on the winding position. The alarm will be counted as Q Registration. If USTER® QUANTUM EXPERT for winding is connected; the signal is transferred to this data system for alarm purposes. With the selection cut, a cut is triggered when a preset alarm limit is reached. The sensor will cut and the alarm will be counted as a Q Cut. The faulty yarn will be removed from the cone with the maximum length of 64 meter. This setting should not be chosen, as a pure cut does not make much sense. The action block is recommended, if it is desired to take an off-quality bobbin out of the process. The winding position will be blocked and the lamp of the sensor lights up. The alarm will be counted as Q Blocking. The behavior of the winding position depends on the machine type. For this, trained personnel are necessary. Depending on the machine type, an automatic bobbin change is carried out or the bobbin must be changed manually. The action block + suck can be recommended, if it is desired to take an off-quality bobbin out of the process. The winding position will be blocked and the lamp of the sensor lights up. The alarm will be counted as Q Blocking. The reference length or evaluation length of the Q parameters CV, H or IP has a fixed maximum length of 64 m if the action at alarm is set to "block + suck". After the blocked winding position has been reset, 64 m yarn will be sucked off from the cone.

7.14

USTER® QUANTUM 3

7


7.3.3

Display of the imperfection results

Fig. 7-15 displays the last measurement over the evaluation length with date and time of: •

neps of all sensitivity levels per winding position

•

thick places of all sensitivity levels per winding position

•

thin places of all sensitivity levels per winding position

Furthermore, it displays the group mean value of all imperfection classes.

Fig. 7-15

Display of the imperfection counts

The results of the sensitivity levels will be marked in color in case of set alarm limits for certain classes. •

green Alarm limit set but no alarm

•

red

7.4

Alarm, the set limit has been exceeded

Class-Alarm

This alarm deals with yarn faults which are classified in the USTER® CLASSIMAT matrix, Fig. 7-17. If one wants to monitor repeatedly occurring yarn faults which are not disturbing as a single event but as a group of faults the winding position can be stopped with the class-alarm. A single D1 fault might not be disturbing, but a series of several D1 faults shortly after each other cannot be accepted in the end product. With the setting of an alarm in this class, e.g. 3 faults per kilometer, the winding position will be stopped when the alarm limit is reached. The bobbin must be removed by the personnel.

USTER® QUANTUM 3

7.15

7


With the USTER® QUANTUM 3 class-alarm, according to the USTER® CLASSIMAT criteria, the has a tool which operates according to the same criteria as the USTER® CLASSIMAT for the laboratory. Seldom-occurring yarn faults are detected, assessed and classified within the well-known CLASSIMAT matrix according to length and mass deviations. This provides the with complete information on the yarn quality and allows him to make a forecast for the subsequent process stages. Based on this information about the quality parameters, the can then apply that knowledge to specifically use the yarn according to the customer's requirement profile. The yarn fault classification is carried out simultaneously at all winding positions according to the USTER® CLASSIMAT: Short thick places with a mass or diameter increase of at least 75%, 45 long thick places with a mass or diameter increase of at least 30% and thin places with a mass or diameter decrease of at least –20% are classified within the CLASSIMAT matrix in 45 thick and thin place classes. This allows the to quickly identify any outlier winding positions. The CLASSIMAT matrix is shown in the following Fig. 7-17.

Fig. 7-16

Classification matrix at the Control Unit

The can select between displays of the detected yarn faults or of all remaining yarn faults. The yarn fault classification is permanently active and cannot be switched off. In addition, there is the possibility of displaying the data of individual winding positions or the complete machine, which also can be printed out via a function key.

7.4.1

Definition of the classes

Fig. 7-17 shows the fault channels of the CLASSIMAT matrix with the fault length (cm) and the fault size (%).

7.16

USTER® QUANTUM 3


Fig. 7-17

7.4.2

7

CLASSIMAT matrix with the fault classes

Reasons and effects of the faults

The increase of the yarn faults can have different causes: •

raw material related, i.e. a change in the raw material quality

•

process related changes, i.e. worn-out machine parts, like e.g. card cloth, defect regulation of the draw box, fly, dirty machines, etc.

The rising of yarn faults is an indicator for a negative change in the textile process, which has to be looked at carefully.

7.4.3

Settings

Fig. 7-18

Setting of the class-alarm at the Control Unit

USTER® QUANTUM 3

7.17

7


Evaluation length It is possible to set the evaluation length between 1 – 6000 km per winding position. This means, that the alarm condition is checked referred to this length. It is recommended to set the evaluation length to 1 km.

Class One out of 23 classes. It is possible to set limits for up to 5 classes.

Alarm limit The alarm limit can be set between 0 and 64000 events until an alarm is triggered.

Action If the alarm limit is reached on a winding position in one out of 5 classes, the iMK reacts according to the setting ACTION at the ALARM window. An entry is made in the logbook in all cases. There are three different action settings: •

•

cut

•

block

If the action “” is chosen, the measurement with a set limit serves only for data collection to monitor the quality of the production. There will be no reaction on the winding position. The alarm will be counted as Q Registration. If USTER® QUANTUM EXPERT for winding is connected; the signal is transferred to this data system for alarm purposes. With the selection cut, a cut is triggered when a preset alarm limit is reached. The sensor will cut and the alarm will be counted as a Q Cut. The faulty yarn will be removed from the cone with the maximum by the winding position ed length. The action block can be recommended, if it is desired to take a bad bobbin out of the process. The winding position will be blocked and the lamp of the sensor lights up. The alarm will be counted as Q Blocking. The behavior of the winding position depends on the machine type. For this, trained personnel are necessary. Depending to the machine type, an automatic bobbin change is carried out or the bobbin must be changed manually.

7.4.4

Display of the class alarms

The class alarm can be triggered for the channels: N/S and L/T. It can be selected between the results of the machine, the group or individual winding positions. The results can be displayed absolute or per 100 km.

7.18

USTER® QUANTUM 3


7

In the upper part of the result window of the individual classes, the status of the measurement is displayed: •

OK:

The set alarm was not reached.

•

ALARM:

The set alarm was exceeded.

In the lower part of the result window, the overall number of events corresponding to the chosen reference length is given.

Fig. 7-19

Display of the class alarms

The result of the class will be marked in color in case a set alarm limit was exceeded. •

green Alarm limit set, but no alarm

•

red

7.5

Alarm, the set limit has been exceeded

Tailored classes (Option Advanced Classes)

The tailored classes offer the possibility to define customer classes or group classes together for special purposes. It is also useful to inspect yarn faults and foreign fibers within the customized class. The aim is to define tailored classes for NSL, T and FD (Fig. 7-20 and Fig. 7-21). The settings can be done by defining sensitivity in % and cm of the upper right and lower left corner for the tailored class for NSL, T or FD. In order to inspect faults within the tailored class the should use the LED function of the sensor. The tailored class will be shown in the classification matrix of the related clearing function. The tailored classes offer the possibility to define custom classes or group classes together for special purposes. Tailored classes are used only for information and will not influence the cut ratio. After changing the tailored class, the data should be cleared (clear counters) otherwise the tailored class values are mixed up with the former settings.

USTER® QUANTUM 3

7.19

7


7.5.1

Settings

Fig. 7-20

Setting of the fault class

Tailored classes for NSL, T and FD can be defined. The settings are: Sensitivity (%) and the length (cm) values of the upper right and lower left corner for the tailored classes NSL, T and FD.

Fig. 7-21

7.20

Setting of tailored the fault class

USTER® QUANTUM 3


7.5.2

7

Display of the tailored classes

The tailored class will be shown in the classification matrix of the related clearing function (Fig. 7-22, right side). “Tailored class” can be used for the LED function.

Fig. 7-22

Classification matrix at the Control Unit (at the “Displays” main menu)

To better understand defects Uster Technologies always recommends to put the fault on a black board (disturbing thick and thin places) and on a white board (foreign fibers). To make this easier the iMH-LED function and the display of defect length, percentage and classification can be displayed on the event report on the CCU (Fig. 7-23). The iMH-LED is turned on, when a tailored class cut is triggered.

Fig. 7-23

iMH LED Display Function for tailored classes

USTER® QUANTUM 3

7.21

7


7.6

Adjustment of the individual alarm possibilities

On new winding machines, the textile alarms are shown on the man-machine interface of the machine. A reset of the textile alarm is carried out by the machine. Depending on the machine type, the reset of the alarm is carried out at a bobbin change. By this, the alarm of the sensor is also deleted. Especially by selecting the same reference length for different quality parameters, it can happen that two different alarms are triggered at the same time. As an example the following event is described: The yarn evenness and the hairiness are monitored over a reference length of 400 m. For both monitoring parameters, the respective limits are set and the action "block" is selected. It is possible, that an off-limit bobbin shows a higher hairiness as well as a higher unevenness. In this case, both alarms can be triggered, i.e. an alarm for CVp and an alarm for Hp.

7.7

Hairiness

Hairiness plays an important role in the textile industry. Hairiness variations in yarns can substantially affect the appearance and the hand of woven and knitted fabrics. Furthermore, hairiness can be disturbing in subsequent processes. With the introduction of compact spinning, the hairiness monitoring on the machine became more and more a must. Since the hairiness of compact yarns is very low, it is important that bobbins which deviate in hairiness can be recognized immediately. Otherwise the fabrics have to be downgraded. Statistical surveys (USTER® STATISTICS) have shown that yarns have become more even. Therefore, variations of the quality characteristics of conventional yarns from bobbin to bobbin have become more disturbing than several years ago. This is also valid for the hairiness.

7.7.1

Principles of operation of the hairiness measuring systems

The oldest hairiness monitoring system represents the counting of the number of protruding fibers at a distance of 3 mm from the yarn body. (Fig. 7-24).

Fig. 7-24

7.22

USTER® QUANTUM 3


7

A testing method with high reproducibility was introduced in the market by Uster Technologies in 1988 with the USTER® TESTER 3. The method is based on a dark field optics (Fig. 7-25 and Fig. 7-26).

Fig. 7-25

Fig. 7-26

Fig. 7-25 and Fig. 7-26 represent the hairiness of yarns from the point of view of the optical receiver. The yarn body is dark, but all the loose and protruding fibers are bright and contribute to the hairiness measurement. The light intensity along the yarn is permanently measured by the receiver. Since the yarn body is dark, it does not contribute to the hairiness monitoring. It is possible to evaluate hairiness and to calculate the absolute hairiness, the hairiness variation and to print out a diagram and a spectrogram of hairiness with this measuring principle. It could be proved in various interlaboratory trials that this measuring method is the most accurate hairiness monitoring system in the industry. Uster Technologies has been publishing USTER® STATISTICS for hairiness since 1989. The conditions for the clearer are different. Therefore, a suitable solution had to be found, which produced comparable results, even with the limited space conditions which are available for the clearer. Fig. 73 and Fig. 74 show a 100% cotton, yellow colored garment. In the zoomed picture (right) it is obvious that the hairiness is rather high.

USTER® QUANTUM 3

7.23

7


Fig. 7-27

Yarn hairiness in garment / 100% cotton, combed, Nec 32 (18,5 tex)

Fig. 7-28

Yarn hairiness in garment, zoomed picture

The following 100% bleached cotton T-shirt (Fig. 75 and Fig. 76) also shows excessive hairiness.

Fig. 7-29

Yarn hairiness in cotton T-shirt / 95% cotton / 5% polyurethane, Nec 34 (17,4 tex)

Fig. 7-30

Yarn hairiness in cotton T-shirt

Measuring method of the USTER® QUANTUM 3 For the USTER® QUANTUM 3, a similar measuring method as for the USTER® TESTER 4 was chosen. The prerequisites for the hairiness measurement are given by the foreign fiber measuring field. However, the evaluation of the signal had to be adjusted. The highest attention was put on the reproducibility of the deviations from the mean value to detect outlier bobbins.

7.24

USTER® QUANTUM 3


7.7.2

7

Settings

Fig. 7-31

Setting of the hairiness parameters at the Control Unit

Reference length It is possible to set the reference length between 50 and 10000 m at the Control Unit. After the length setting the alarm condition is checked and a new measurement is started. As already mentioned for the monitoring of the yarn evenness, it is necessary to adapt the reference length to the respective quality demands. Depending whether changes of the hairiness should be monitored or only ed, the reference length will be different. •

For data collection: For the monitoring of the hairiness, it is recommended to select a reference length of 400 m starting from the bobbin tip (see "measurement"). As the yarn hairiness increases over the bobbin length, it is guaranteed that results measured under the same circumstances can be compared with each other. A longer reference length is not recommended, as the hairiness increases at the bottom part of the bobbin. For pure data collection, no action is taken in case of exceeding limits.

•

For the selection of bad bobbins: The selection of the reference length depends on the quality requirements. The reference length must be derived from the expected hairiness deviations of the yarn. The monitoring of faulty yarn must be carried out continuously (see section "Measurement" below). This guarantees that bobbins, which do not meet the quality requirements, can be taken out of the winding process (action: block). In case of compact spinning it is particularly the compacting zone in the case of compact spinning which can considerably influence the hairiness. Such faults can affect the hairiness over the whole bobbin length.

USTER® QUANTUM 3

7.25

7


Measurement The measurement can be carried out: •

•

continuously

at bobbin change

The following winding machines provide a bobbin change signal. This means that the winding position transmits a trigger signal to the clearer, when a bobbin change is carried out: •

Murata PC 21

•

Schlafhorst Autoconer 338

•

Savio Orion

•

Schlafhorst Autoconer AC5

•

Savio Polar

MV-monitoring (group mean value) Upper alarm limit H MV: Lower alarm limit H MV:

0,1 – 20.0 0,1 – 20.0

SP-monitoring (winding position) Deviation of the SP-monitoring from the group mean value. Upper alarm limit SP: Lower alarm limit SP:

0,1 – 20.0 0,1 – 20.0

Action If the hairiness of a winding position is exceeded on one of the alarm limits, the sensor will react according to the setting ACTION at the ALARM window. There are four different possibilities: •

•

cut

•

block

•

block +suck

If the action “” is chosen, the measurement with a set limit serves only for data collection to monitor the quality of the production. There will be no reaction on the winding position. The alarm will be counted as Q Registration. If USTER® QUANTUM EXPERT for winding is connected; the signal is transferred to this data system for alarm purposes. With the selection cut, a cut is triggered when a preset alarm limit is reached. The sensor will cut and the alarm will be counted as a Q Cut. The faulty yarn will be removed from the cone with the maximum by the winding position ed length. This setting should not be chosen, as a pure cut does not make much sense. The action block can be recommended, if it is desired to take a bad bobbin out of the process. The winding position will be blocked and the lamp of the sensor lights up. The alarm will be counted as Q Blocking. The behavior of the winding position depends on the machine type. For this, trained personnel are necessary. Depending to the machine type, an automatic bobbin change is carried out or the bobbin must be changed manually.

7.26

USTER® QUANTUM 3


7

The action block + suck can be recommended, if it is desired to take a bad bobbin out of the process. The winding position will be blocked and the lamp of the sensor lights up. The alarm will be counted as Q Blocking. The Reference length or evaluation length of the Q parameters CV, H or IP has a fixed maximum length of 64 m if the action at alarm is set to "block + suck". After the blocked winding position has been reset, 64 m yarn will be sucked off from the cone.

7.7.3

Display of the hairiness values

Fig. 7-32 shows the hairiness results per spinning position, the mean value of the hairiness per group as well as the upper and lower alarm limit.

Fig. 7-32

Display of the Hairiness value

•

SP UPPER ALARM LIMIT The indicated upper absolute hairiness alarm limit is calculated from the hairiness mean value of the group and the preset upper hairiness alarm limit.

•

SP LOWER ALARM LIMIT The indicated lower absolute hairiness alarm limit is calculated from the hairiness mean value of the group and the preset lower hairiness alarm limit.

Any hairiness value of a winding position that is above or below the absolute SP ALARM LIMIT will trigger a Hp or Hm alarm. At the same time, it is possible to read the deviation from the mean value out of the display for Textile Alarms. As far as information on hairiness only is desired, there is the possibility to set the alarm limits without selecting any actions. In this case, the number of events exceeding the limits is indicated in the shift report.

USTER® QUANTUM 3

7.27

7


7.7.4

How do hairiness variations affect woven and knitted fabrics?

Uster Technologies has investigated various aspects of hairiness in order to clarify the effect of hairiness variations on fabrics.

Patterns in the fabrics First test: The effect of hairiness variation on woven fabrics was investigated after dyeing. Fig. 7-33 shows the consequences on a fabric consisting of 100% cotton in the weft. The yarns with various hairiness values were inserted in the weft. The four yarns were of the same count but had different hairiness values of 5.7, 6.9, 7.9 and 9.0.

Fig. 7-33

It is obvious in Fig. 7-33 that the human eye can recognize hairiness differences of H = 1. The same trials were carried out with a viscose yarn with the same result. Investigations on hairiness variations on fabrics made out of compact yarns have shown that differences of H = 0,6 ... 0,7 could already be recognized .

7.7.5

Hairiness monitoring on the machine

The textile industry is aware of the fact that the hairiness on all the spinning positions must be kept under control. Therefore, it is strongly required that the hairiness is measured on the machine so that 100% of the yarn is monitored. The following events have generated the need for such monitoring systems: •

Since 1988 a highly reproducible hairiness testing system is available with the USTER® TESTERS 3 and 4. The experience with these systems and the consequences on fabrics have proven that hairiness deviations of only H = 1 can be seen in the fabrics after dyeing. Therefore, hairiness variations have to be avoided.

7.28

USTER® QUANTUM 3

7


•

Compact yarns have only very little hairiness. Therefore, compact yarns with only small deviations can easily be recognized in the fabric. Contamination and defects in the compacting zone can prevent the correct formation of compact yarns. This can lead to the production of a yarn with "normal" hairiness, instead of a yarn with only a little hairiness. After dyeing, such hairiness variations become clearly visible.

7.7.6

On-line tests versus off-line tests

The laboratory tests for hairiness can be regarded as benchmarks for the textile industry. The USTER® STATISTICS are also available for such tests. Fig. 7-34 shows the correlation of the USTER® off-line system with the on-line system. These tests were carried out by installing the USTER® on-line system in the thread-line of the USTER® TESTER.

12,00 Com4 11.8Tex 10,00

Com4 11.8Tex Com4 11.8Tex Ring gek. 14.7Tex

8,00

Ring 24.6Tex Ring 16.4Tex 6,00

Ring kard.19.7Tex Ring 50%PES 29.5Tex Com4 gek.7.7Tex

4,00

Com4 11.8Tex Ring kard. 20Tex 2,00

Comp Süssen 20Tex

14,00

12,00

10,00

8,00

6,00

4,00

2,00

0,00

0,00

Ring 100Tex

Hairiness USTER TESTER 5 4 TESTER Hairiness USTER

Fig. 7-34

The correlation between the off-line and the on-line measurement in Fig. 7-34 is very good. However, practice has shown that such ideal conditions as shown in Fig. 7-34 are not always given on the winding machine. As already mentioned, there are many factors which influence a correlation with the measurements in the laboratory. For this reason, as for the results of the yarn evenness, the absolute values of the hairiness will not exactly correlate with the results in the laboratory. However, there is a very good correlation regarding the relative deviations from the mean value.

USTER® QUANTUM 3

7.29

7


It must be taken into , that the winding machine increases the hairiness. This applies mainly for the unwinding of the yarn from the bobbin with high speed, for yarn tensioners and deflection devices.

7.7.7

Basic hairiness differences between the different spinning methods

Hairiness characteristics within a bobbin or a package depend on the spinning system. The knowledge of hairiness characteristics is important for comparison tests between the off-line and the on-line systems for reaching high accuracy and reproducibility. For conventional ring-spun yarns, the hairiness increases from the bobbin tip to the bobbin base. The increase is in the order of about 10% (Fig. 7-35). In comparison to ring-spun yarn, for compact yarns the increase of the hairiness from the bobbin tip to the bobbin base only reaches about 2 to 4%. The origin of these within-bobbin variations is the ring rail movement causing varying balloon sizes and varying angles of the yarn at the ring traveler.

Fig. 7-35

Hairiness variation of yarns produced by various spinning systems

Fig. 7-35 shows the hairiness variation within a cross-wound cone. In the case of ring-spun yarn, the test was made after winding. Since the conditions on the OE rotor spinning machine are the same at any time, there is also a constant hairiness throughout the package. Therefore, if values of on-line systems have to be compared with off-line systems, it has to be taken into consideration that the laboratory results represent only 400 m of yarn from the bobbin tip. For comparison it is, therefore, recommended to measure the bobbin tip on the winding machine as well. The USTER® QUANTUM 3 allows this measurement for all winding machines which generate a bobbin change signal.

7.30

USTER® QUANTUM 3


7

Fig. 7-36 shows the hairiness from the tip of the bobbin to the base, each test representing 400 m of yarn. In Fig. 7-36, the bobbin tip is represented with blue color, the bobbin base in light red color. 5

4,8

4,6

4,4

4,2

4 1

2

3

4

5

6

7

8

9

10

blue: bobbin tip – red: bobbin base

Fig. 7-36

7.7.8

6 measurements, 400 m per bobbin, through the bobbins

Practical examples

Hairiness monitoring on ring-spun yarns On a winding machine, 460 bobbins were tested regarding the hairiness. Yarn: Nec 30, 100% cotton, combed, ring-spun yarn. Fig. 7-37 shows the results of a series of measurements of 460 bobbins. It can be clearly recognized that the hairiness results are scattered around the mean value of H = 4,8. Furthermore, there are 5 winding positions with a hairiness beyond the set limits. Outlier winding positions

5.8

5.6

5.4

Hairiness H

5.2

5

4.8

4.6

4.4

4.2

4 1

21

41

61

81

101

121

141

161

H

Fig. 7-37

181

H-Mw

201

221

241

261

limit Hm - 0.7

281

301

321

341

361

381

401

421

441

Winding positions

limit Hp + 0.7

Measurement of the hairiness of a conventional ring-spun yarn

USTER® QUANTUM 3

7.31

7


Abbreviations H

= Single value for the hairiness

H-MW

= Mean value of the hairiness of the group

Limit Hp +0,7

= Positive limit (red) set to +0,7 with reference to the mean value

Limit Hm -0,7

= Negative limit (blue) set to –0,7 with reference to the mean value

Hairiness monitoring of compact yarns On a winding machine, 160 bobbins were tested regarding the hairiness. Yarn: Nec 50, 100% cotton, combed, compact yarn. Fig. 7-38 shows the results of a measurement of 160 bobbins of compact yarn. In comparison to the measurements of a ring-spun yarn shown in Fig. 7-37, the values are located much closer around the mean value. Furthermore it can be seen that the mean value of the hairiness is much lower than the mean value of conventional ring yarn. This was also experienced with off-line measurement.

3.4 3.3 3.2 3.1

Hairiness H

3.0 2.9 2.8 2.7 2.6 2.5 2.4 2.3 2.2 2.1 2.0 1

21

41

H

Fig. 7-38

61

H-MW

81

101

Hm-limit -0,5

121

141

Winding positions

Hp-limit +0,5

Hairiness measurement of a compact yarn

Abbreviation: H

= Hairiness

MW-group

= Hairiness mean value of the group

Hm-limit –0,5

= Negative limit (blue) is set to –0,5 with reference to the mean value

Hp-limit +0,5

= Positive limit (red) is set to +0,5 with reference to the mean value

7.32

USTER® QUANTUM 3


7.8

7

Indication of ejected bobbins

If the operator is interested in marking the alarmed bobbin in order to re-check them off-line in the laboratory, he can select the "continuous printout". For this purpose, it is possible to print out the Qalarms by selecting the feature of the "continuous printout" at the Control Unit. After each stop, a printout follows. This printout provides information to the operator about the alarm reason and the deviation from the nominal value. This printout can be attached to the bobbin and further analyses of the bobbin can be carried out in the laboratory.

7.9

Criteria to select the limits for quality characteristics

Bobbins which exceed the selected limits for quality characteristics have to be ejected at the winding machine. For this purpose, we have to discuss the characteristics which can be detected with a modern yarn clearer: •

Unevenness

•

Hairiness

•

Frequent thin places

•

Periodic faults (pearl chains)

•

Frequent thick places

•

Excessive cuts

•

Frequent neps

•

Clusters of faults

In establishing a real quality management system, it is of utmost importance that selections made by the yarn clearer with respect to quality characteristics can be verified in the laboratory. The following examples to explain what this means. Fig. 7-39 shows the determination of hairiness on the machine. Hairiness 4.65

4.55

4.45

4.35

4.25

4.15

0

Fig. 7-39

3

6

9

12

15

18

21

24

27

30

33

Weeks

On-line monitoring of hairiness / Count: Nec 30, ring-spun yarn, cotton, combed

In week 10 a massive increase in the hairiness can be noticed.

USTER® QUANTUM 3

7.33

7


Fig. 7-40 shows the distribution of the hairiness on the winding machine. A selection criterion was set to select the bobbins which exceed the warning limit. Frequency 300

250

200

150

Selected limit for separating bobbins

100

50

Hairiness

Fig. 7-40

4.66

and higher

4.58

4.51

4.43

4.27

4.35

4.12

4.20

4.04

3.96

3.89

3.81

3.73

3.65

3.58

3.50

3.42

3.34

3.27

3.11

3.19

3.03

2.96

2.88

2.80

0

On-line hairiness measurement / Count: Nec 40, ring-spun yarn, cotton, combed

Fig. 7-40 shows the distribution of the hairiness measured on a winding machine on 2500 bobbins. A limit was set to separate and eject bobbins which will lead to visual disturbances in a fabric.

7.9.1

Installation of a quality management system to eliminate outliers

In the previous chapters, it was explained in detail how modern quality management tools can contribute to the improvement of the performance of a spinning mill. However, we identified one major area where mill managers and quality managers still suffer. This is the area of outliers. Since one single thread in the warp on a weaving machine can downgrade the entire woven fabric, it is of utmost interest to get rid of outliers.

An average ring spinning mill has a size of 20,000 to 30,000 spindles. In comparison with other industrial activities, the number of production positions in spinning mills is very high. Therefore, a well organized spinning mill will have a repair crew which permanently improves outliers among the production positions. The repair crew, however, needs input from the laboratory where systematic quality analyses are made.

7.34

USTER® QUANTUM 3


7

Fig. 7-41 shows the principles of operation in a modern spinning mill.

Fig. 7-41

The bobbins which are ejected by the winding machine are analyzed in the laboratory. Outliers are brought back to the normal distribution.

The bobbins of individual spinning machines are marked to identify the production positions where the ejected bobbins came from. The ejected bobbins are brought to the textile laboratory, where the quality problems are evaluated. The findings are listed on an instruction sheet for the repair crew. The intention to bring the outliers back within the normal distribution range (Fig. 7-41). The repair crew has to undertake the repair work at the machines (Fig. 7-42). Successful repairs are reported back to the laboratory.

Fig. 7-42

Recommendations for a systematic quality management

Bobbins which are recognized as having tolerated quality characteristics will go back to the yarn batch. The outlier bobbins will be handled as second-grade bobbins.

USTER® QUANTUM 3

7.35

7


7.9.2

Tracing back outlier bobbins to the source

Bobbin identification method The easiest way to trace back outlier bobbins is the designation of each bobbin with the number of the spinning position. This identification can be realized for one ring spinning machine within 20 minutes. Fig. 7-43 shows the identification of the bobbins.

Ejected bobbins from winding machine

Entry of marked spindle in action plan

Laboratory

Marking of spindle position

Fig. 7-43

Action plan for repair crew

Identification of spinning positions for one doff

If the winding machine ejects a bobbin from this ring spinning machine, it is easy to find the spinning position where the bobbin was produced. Therefore, it is recommended, particularly in low cost countries, to designate the bobbins of one doff and one machine every day. In a medium size spinning mill of 20’000 to 30’000 spindles it will last approximately 20 to 30 day to check and trace back all the outlier bobbins in a mill.

Identification process: •

The spinning mill establishes a test plan which ring spinning machine has to be tested at what day.

•

All the bobbins of this machine are identified for one doff so that the laboratory operators know where the ejected bobbin came from.

•

The production position which produced the ejected bobbin is entered into the action plan for the maintenance and repair crew.

•

The maintenance and repair crew receives an action plan from the laboratory.

Fig. 7-44 shows part of an action plan for the maintenance and repair crew. The yellow part is filled in by the laboratory staff. This part also has a column where the laboratory operators insert the expected source of the fault. The green part of the action plan is filled in by the repair crew. They also confirm if the expected source proposed by the laboratory staff was correct. If the crew finds another fault, the technical problem is described in detail.

7.36

USTER® QUANTUM 3

7


The action plan goes back to the laboratory the same day when all the actions are finished. Machine

Spinning position

Detection in laboratory

Expected source

Source found by repair crew

Action taken

Time for repair

Signature

Date

14 RSM

231

Peak in spectrogram at 8 cm

Damage on front roller, ring spinning

Contamination of front roller due to honeydew

Cleaned front roller

10 min

June 25, 2007

14 RSM

284

High periodic hairiness

Ring traveller

Ring traveller worn out

Replaced ring travellers

5 min

June 25, 2007

Periodicity at 28 m

Contamination of drawbox of finisher drawframe

Same

Cleaned drawbox of finisher drawframe

10 min

June 25, 2007

3 Finisher drawframe

Fig. 7-44

Systematic repair of defective production positions

Lessons learned with the first systems in mills: •

The yarn monitoring system on the last machine in the spinning process also has to check the quality characteristics.

•

The monitoring of the quality characteristics on the winding machines offers new opportunities to considerably lower the daily outlier bobbins.

•

Modern on-line systems spinners to keep the quality of every yarn package within pre-set limits.

Outlier bobbins produced by non-identified spinning positions As has been mentioned above, the bobbins of all spinning positions are identified once in 20 to 30 days. This method allows a precise tracing back of outlier bobbins to the source of the problem. However, in a spinning mill with 25 ring spinning machines there are 24 machines which deliver nonidentified outlier bobbins to the laboratory via the winder at a certain date. If there is a clear assignment in the mill what kind of bobbins were processed on what winding machines, it also allows the assignment of the type of problems at least to a specific spinning machine. If a spinning mill uses link systems, the back tracing of the bobbins to the ring spinning machine is easy. In spinning mills with stand alone winders it depends on the organization of the mill. Example: If more and more non-marked bobbins exceed the hairiness thresholds, it may be time to replace the ring travelers.

USTER® QUANTUM 3

7.37

7


7.9.3

Examples from the industry

The closed loop system was tested in the industry with considerable success. If the clearer really can detect quality deviations from established benchmarks, it will also be possible for the quality specialists to trace back the yarn faults to the origin. The following are a few examples where faults could be traced back to the ring spinning machine.

Examples 1 and 2 A bobbin was ejected by the automatic winding machine as an outlier, because the evenness (CVm) was too high. In the laboratory the high evenness could be confirmed. Since the bobbin was identified with the spinning position at which the yarn was produced, the repair crew found that the top roller of the respective drawbox was contaminated with honeydew (Fig. 7-45).

Fig. 7-45

Honeydew deposit

Fig. 7-46

Defective apron

Another outlier bobbin was ejected at the winding machine because the number of S-faults was too high. A check at the spinning machine could clarify that a defective apron with a hole has caused this alarm at the yarn clearer (Fig. 7-46).

7.38

USTER® QUANTUM 3


7

Examples 3 and 4 Another outlier bobbin was ejected because of a high number of S-faults. After having confirmed this in the laboratoary as well, the check at the respective spindle at the ring spinning machine has shown that the apron of the drawbox moved in the wrong direction, and, therefore, the t was defective (Fig. 7-47).

Fig. 7-47

Wrong direction of apron, bad t

Fig. 7-48

Intensive contamination at output of drawbox

A bobbin was identified as outlier by the yarn clearer because the number of imperfections was too high. The check at the ring spinning machine has shown an accumulation of fiber fragments at the locations indicated by yellow arrows in Fig. 7-48.

7.9.4

Recommendations for a sampling plan

There are some limitations on the winding machine to reach the same accuracy as spinners reach in the laboratory. The reasons for these limitations are: •

Long maintenance cycles for clearers

•

Contamination of the measuring zones of on-line systems as a result of a permanent monitoring, 24 hours a day, 7 days per week

•

The yarn speed is not constant on a winding machine. Therefore, periodic mass variations cannot be measured directly on the winding machine. Periodic events have to be measured by indirect measurements such as the higher evenness or the frequent occurrence of thick and thin places. However, in the laboratory the operator can measure the yarns at constant speed and, consequently, an accurate spectrogram can be determined. With this precise information of specific periodicities the textile laboratory can elaborate a detailed action plan.

•

The microclimate on the winding machine near the yarn clearer is given by various variables such as the environmental conditions in the winding room, the heat produced by the winder, etc. In the laboratory the environmental conditions are defined by international standards.

As a result of this it is strongly recommended to check the bobbins in the laboratory which are ejected at the winding machine due to quality problems. Table 7-2 is a recommended test procedure for a textile laboratory in a mill with 27’000 spindles, cotton 100%, combed, count range Ne 30 to Ne 50.

USTER® QUANTUM 3

7.39

7


Machine

No. of machines or positions

Card

First drawframe

Comber

Finisher drawframe

Roving frame

Ring frame

Winder **

Quality characteristics

Test intervals

Test speed

Test length

Required test time per day *

12

Evenness Diagram Spectrogram Variance-length curve

2 per day

100 m/min

250 m

8 min

2


2 per day

100 m/min

250 m

8 min

12


2 per day

50 m/min

250 m

16 min

4


4 per day

50 m/min

250 m

32 min

600


5 roving bobbins per day

100 m/min

250 m

16 min

27’000

Evenness Diagram Spectrogram Imperfections Hairiness Yarn diameter Density Trash

800 m/min

1000 m

169 min

60 ejected bobbins from winding machine daily

800 m/min

1000 m

113 min

20 cones per day

800 m/min

1000 m

39 min

600

Evenness Diagram Spectrogram Imperfections Hairiness Yarn diameter Density Trash

10 bobbins per machine every third day (90 bobbins daily)

401 min

Total Table 7-2 * **

Total test time required in the laboratory per day for this example

Time required also includes setting of instrument and sample preparation The amount of 60 ejected bobbins per day is equivalent to 0,022% of the daily production or 3,5 kg of yarn (Basis: Nec 30).

7.40

USTER® QUANTUM 3

7


The total test time per day is equivalent to 401 minutes or 6 hours and 41 minutes. This indicates that the tests can be managed in one shift. The total test time is based on an average work load in the laboratory. However, the slivers of the cards, drawframe, combers, etc., can also be measured at the same day. As a measure for corrections at machines with non-identified bobbins we recommend to study the action plan once per day, to check the analysis of the outlier bobbins, to walk along each machine and to check the spinning positions.

7.9.5

Conclusion

Most of the spinning mills have an established quality management system based on sample testing. With such a quality system, however, it may last year or more to get rid of outliers. This paper describes a method with which outlier bobbins can permanently be separated on the winding machine with the help of yarn clearers and traced back to the faulty spinning position. The method which is described in this paper also allows the daily elimination of outlier bobbins. The described system is used by various mills with considerable success.

7.10

Yarn evenness (CV), hairiness and imperfections and their effect on the fabric appearance

7.10.1 Reasons and measures to minimize random mass variations In Table 7-3, the origin of faults related to random mass variations is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. RANDOM MASS VARIATIONS Origin of Faults


Card

Regular maintenance

Drawing frame

Apply autoleveller at finisher drawframe / Regular maintenance of drawing elements

Roving frame

Incorrect setting of the roving traverse

Ring spinning frame

Incorrect break drafts Dimension of apron Aprons change schedule and quality of aprons Excessively worn aprons

USTER® QUANTUM 3

7.41

7


RANDOM MASS VARIATIONS Origin of Faults

Possible Reasons and Preventive Actions Top roller grinding schedule Top roller hardness Cot condition and hardness Roll chatter Top roller minimum diameter Dimension of spacers Training of operators (avoid cutting top roller) Yarn diameter differences Excessive balloon tensions Incorrect roller settings Top front rollers are out of position Pigtail centering Worn rings Periodic mass variation from previous processes Roller weightings Improper apron spacing

®

RANDOM MASS VARIATIONS / USTER Tools for Improvement Tools

Improvement ®

Constant quality control of sliver and yarn ® quality with the USTER TESTER (spectrogram)

®

Adjustment of autoleveller

®

Proper setting of the “pearl chain” option for alarms

USTER Testing off-line

USTER Testing on-line USTER QUANTUM CLEARER

Separate bobbins with high CVm with quality data option The quality data setting for CVm can be used to separate bobbins with high CVm ®


Table 7-3

7.42


Preventive measures and tools for the management of random mass variations

USTER® QUANTUM 3

7


7.10.2 Reasons and measures to minimize imperfections Uneven fabric appearance is the result of too many thin places, thick places and neps. There are various reasons for an excessive formation of imperfections. In this section, some of these reasons will be explained with the help of pictures of the knitted samples and their yarn quality results.

Mix-up of a reference yarn with a yarn of a high imperfection level During compact yarn production, the air suction area in the compacting zone can become clogged for a variety of reasons. This affects the spinning process in a negative way and can increase the number of imperfections and especially neps. In our example, we have tested a reference compact yarn and a defective compact yarn arising from a clogged compacting zone. If we check the CVm values, thin places (-50%), thick places (+50%) and neps (+200%) of the two yarns, we can see a significant difference. In particular, the number of thin places (-40%), thick places (+35%) and small neps (+140%) have increased significantly (Table 7-4).

Referencecompact yarn

Yarn Count (Ne)

Twist 1/m

Twist direction

CVm %

Thin -50%

Thick +50%

Neps +200%

H

2DØ mm

CV2D (8mm)

D (abs) 3 g/cm

30

770

Z

10.1

0.0

6.0

8.0

3.7

0.20

7.5

0.6

<5

<5

11

<5

62

10.5

1.0

12.0

19.0

4.0

51

23

80

USP07 Defectivecompact yarn

30

770

USP07

Z

<5

34 0.21

7.9

52

Thin -40%

Thin -50%

Thick +35%

Thick +50%

Neps +140

Neps +200

3.0

0.0

45.0

6.0

46.0

8.0

USP07

<5

<5

<5

11

<5

<5

Defective compact yarn

13.0

1.0

76.0

12.0

100.0

19.0

24

51

34

23

Reference compact yarn

USP07

Table 7-4

28

0.6

Yarn quality results, well maintained and badly maintained compact spinning machine

We made fabric simulations for these two yarns using the USTER® TESTER 5 fabric simulation program and the results are given in Fig. 7-49 and Fig. 7-50. The increase in the number of the small neps can be seen in the right hand picture. The neps (+200) are shown as white points and indicated by white arrows.

USTER® QUANTUM 3

7.43

7


Fig. 7-49

Fabric simulation of reference compact yarn

Fig. 7-50

Fabric simulation of defective compact yarn

In Table 7-5 the origin of faults related to imperfections is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. YARN IMPERFECTIONS Origin of Faults

Possible Reasons

Thick places & Thin places Comber

Excessive short fiber content

Roving frame

Lint or fly on roving

Ring spinning frame

Lint build up on drafting rolls Blown in lint Apron and cot conditions Apron spacing Out of position top front roll Incorrect roving traverse High balloon tensions Loaded travelers Draft distributions (break draft)

7.44

USTER® QUANTUM 3


7

YARN IMPERFECTIONS Origin of Faults

Possible Reasons Roller spacing Condition and hardness of top cots Eccentric or damaged front rolls (top or bottom) Too coarse fiber Wrong drafting zone settings Bad conditions of top rollers Bad operation of the overhead cleaner Extreme air conditions

Neps

Nep levels in roving Apron worn out Tensor pin opening Ring and traveler worn out Improperly set traveler clearers Balloon control ring worn out

Raw material:

Length uniformity Short fiber content High micronaire variations High level of neps

®

YARN IMPERFECTIONS / USTER Tools for Improvement Tools

Improvement ®


Proper bale management and laydown management ®

Systematic quality control of sliver and yarn quality with USTER TEST® ER / imperfection counts and comparison with USTER STATISTICS ®

Use the imperfections block function form the Q DATA option and separate those bobbins with excessive counts

®

Monitor long-term variations of cut ratio and yarn quality

USTER QUANTUM CLEARER USTER EXPERT SYSTEMS Table 7-5

Preventive measures and tools for the management of yarn imperfections

USTER® QUANTUM 3

7.45

7


7.10.3 Reasons and measures to minimize excessive hairiness and hairiness variations There are various reasons for the formation of excessive hairiness and hairiness variations. In this section, some of these reasons will be explained with the help of pictures of the knitted samples and their yarn quality results.

Different ring spinning techniques In this trial, two different ring spinning techniques were compared on the same T-shirt sample: conventional ring spinning and the compact spinning technique. We have knitted 10 rows of reference yarn (conventional, Nec 36, 16,5 tex) and 10 rows of a compact yarn (compact Nec 36, 16,5 tex) spun from rovings produced from the same cotton blend. We can observe horizontal dark and light colored lines in the T-shirt sample. These horizontal lines are the result of yarn hairiness difference (Fig. 7-51 to Fig. 7-54). This significant difference can also be observed in Table 7-6.

Reference

Yarn Count (Ne)

CVm %

Thin -50%

Thick +50%

Neps +200%

H

sh

2DØ mm

CV 2D% (8mm)

D (abs) 3 g/cm

36

12.6

0.6

33.1

71.7

5.2

1.30

0.20

9.6

0.5

48

19

61

65

76

>95

12.2

0.20

30.2

76.4

4.0

0.93

37

<5

57

67

<5

19

USP07 Compact USP07

36

40 0.19

9.4

0.6 <5

Table 7-6


Fig. 7-51

Reference T-shirt

Fig. 7-52

Defective T-shirt

Fig. 7-53

Reference Fabric

Fig. 7-54

Defective fabric (mix-up of compact yarn)

7.46

USTER® QUANTUM 3


7

Less twist The twist of the yarn has a decisive effect on the hairiness: the lower the twist, the higher the hairiness, and thus the hairiness decreases with increasing yarn twist. This correlation can be explained by the fact that, in cases of a high twist, the number of protruding fibers decreases because most of these fibers are embedded into the yarn body. The spindles of the ring frame are driven by one or more belts which engage the whorls (pulleys) that project from the bottom of the spindle. Slippage of the belts can lead to twist losses, which vary from spindle to spindle. These variations can cause barré and stripping problems when the yarn is assembled into the finished fabric [2].

Eccentric rings/spindles As is well-known, both eccentric spindles and rings can increase the hairiness of the yarn as well as influence its strength and elongation, especially at high eccentricities. Additionally, the life of an eccentric spindle is shorter than a normal one and it has a higher noise level. An eccentric spindle, or a displaced guide or ring, can also increase the end-breakage rate remarkably, because of the periodic tension variation at each revolution. In Table 7-7, the origin of faults related to excessive hairiness and hairiness variations is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. EXCESSIVE HAIRINESS Origin of Faults

Possible Reasons

Raw material

Fiber length Length uniformity Excessive short fiber content

Spinning preparation, spinning and winding

Roving twist Age and type of rings & ring travelers (ring spinning) Spinning tension (ring spinning) Yarn twist Slipping spindle belts Damaged pigtail guides High winding speed Condition of rings Eccentricity of spindles & rings Traveler changes Full bobbin diameter Yarn twist Damaged or worn travelers Separator slap Improperly positioned or missing anti-balloon rings Spindle speed

USTER® QUANTUM 3

7.47

7


EXCESSIVE HAIRINESS Origin of Faults

Possible Reasons Spindle speed curve Improper traveler weights Damaged cots Improperly centered pigtail guides Variation of spinning climate ®

EXCESSIVE HAIRINESS / USTER Tools for Improvement Tools

Improvement ®

Systematic quality control of sliver and yarn quality with ® ® USTER AFIS system (short fiber content) and USTER TESTER, hairiness sensor

®

Use quality data settings for hairiness to separate spinning bobbins with excessive hairiness

®



USTER QUANTUM CLEARER USTER EXPERT SYSTEMS Table 7-7

7.48

Preventive measures and tools for the management of excessive hairiness and hairiness variations

USTER® QUANTUM 3

8

Foreign fibers

8

Foreign fibers

8.1

Introduction

Foreign fibers are one of the major problems in spinning mills. The global ITMF [3] survey on cotton contamination in 2009 showed that, in the perception of spinners from around the world, contamination remains a serious problem. During the past 20 years the degree of significantly contaminated cotton bales has been increasing steadily from 14% to 22%. Organic matter is still the main contaminant, followed by fabrics of cotton and plastic film, strings of jute and plastic [3]. These fibers can be of different origin, character, structure or color. There are distinct benefits to early detection and removal of unwanted fibrous material, since subsequent processing stages open up and spread out these “foreign fibers.” This can result in the contamination of many yarn packages [1]. Fabrics containing foreign fibers cannot be dyed homogeneously, and these fibers can cause many quality problems, especially after finishing [4]. Foreign fibers and materials adversely affect processing, produce end breaks and also affect the dye uptake, fiber reflectance and the appearance of the final product [2]. It is obvious that foreign matter in textile fabrics can no longer be accepted. Therefore, the fight against foreign material in cotton has to cover all the areas where this type of contamination can occur. Many foreign fiber problems are detected only after finishing, and the spinner is ultimately held responsible for the damage.

Therefore, the costs for such claims can be considerable, and provisions have to be made to absorb such claims if the spinning mill does not have a quality management system to eliminate or minimize the number of foreign fibers in yarns. The following is a collection of experience with foreign matter removal systems prior and after the card. Fig. 8-1 and Fig. 8-2 show separated foreign material in cotton.

Fig. 8-1

Separated foreign material in cotton

USTER® QUANTUM 3

Fig. 8-2

Separated foreign material in cotton

8.1

8

Foreign fibers

In Fig. 8-3 and Fig. 8-4 we can see the result of a large blue plastic part which was cut into individual fibers by the card. As can be seen the cotton fibers are contaminated with blue colored plastic fibers. The plastic fiber cluster (Fig. 8-3 and Fig. 8-4) will result in foreign fibers in yarns.

Fig. 8-3

Fig. 8-5

8.2

Plastic fibers in card sliver

Fig. 8-4

Plastic fibers in card sliver

Various foreign fibers in yarns at different magnification / inorganic material

USTER® QUANTUM 3

Foreign fibers

8.2

8

Dense Area

Another new, innovative and unique feature of the USTER® QUANTUM 3 is the “Dense Area”. The dense area in the scatter plot (appearance versus length) is the display of the range where foreign fibers are occurring very frequently but which can hardly be recognized in a fabric because they are very small (Fig. 8-6). This display of the dense area helps the to set a clearing limit easier with an optimal balance between quality and productivity. The dense area depends on the raw material. If a yarn is produced from cotton having a lot of foreign matter or vegetables, then the dense area will be wider and a high number of cuts have to be expected. Similar to the yarn body, after running only a few kilometers of yarn, the first impression of the dense area and the significant foreign fibers will appear. The blue colored dense area is used to visualize the distribution and frequency of clearing limits for the Foreign Matter (FD). By this means a quality analysis of the degree of contamination for different yarns can be easily done. With multicolored light sources the new FM sensor can see all colored foreign fibers and enables the classification of vegetables separately. Having detected all the defects, the USTER® QUANTUM 3 smartly splits the foreign matter into two pools, disturbing colored foreign fibers and mostly non disturbing vegetable foreign matter (see chapter 9). Separate limits for foreign fibers and vegetable matter can be defined. Fig. 8-6, shows a dense area with yarn faults as seen by the USTER® QUANTUM 3, with all the frequent remaining events recorded in the yarn (blue dots), and with the marked area of the yarn body (blue area) and the area of the disturbing yarn faults (red dots). The vertical scale represents the visual appearance or intensity and the horizontal axis represents the FD faults length in cm.

Fig. 8-6

Display of the dense area and the scatter plot for foreign matter

USTER® QUANTUM 3

8.3

8

Foreign fibers

Examples of various dense areas:

Fig. 8-7


Examples of various dense areas:

Fig. 8-8

8.4


USTER® QUANTUM 3

8

Foreign fibers

8.3

Foreign fibers

8.3.1

Types of foreign material in cotton

There are various spinning mills which permanently eliminate foreign matter manually from the bales. However, this method only allows the elimination of larger particles. Small foreign fibers such as human or animal hair cannot be eliminated with such methods because they cannot be detected. The International Textile Manufacturers Federation ITMF investigates the contamination of cotton bales on a global scale. The classification of foreign material in bales leads to Table 8-1. [5] Type of contamination

Designation

Origin

Cotton-related contamination

honeydew

insects

leaf

cotton plant

stem

cotton plant

bark

cotton plant

trash

cotton plant

seed coat fragments

cotton boll

woven plastic

packing material

jute

packing material

plastic fragments

foreign matter blown into the fields

strings

for cotton bags

bird feathers

natural contamination

grass

contamination during harvesting

paper

contamination of cotton fields

leather


human and animal hair

s with humans and animals

rust

machines or transportation trucks

metal plates / wires


oil / grease

machines or transportation trucks

rubber


stamp colorant

identification of bales

tar


Contamination of natural and manmade origin

Table 8-1

Contaminations found in cotton (Source: ITMF 2009 [5])

Depending on the growth area and the harvesting methods the type and number of foreign material can change considerably.

USTER® QUANTUM 3

8.5

8

Foreign fibers

Foreign fibers Foreign fibers are all kinds of fiber type materials, which cling to the yarn. They can be of different origin, composition, structure and color. They occur as single fibers as well as in fiber bundles. The length of foreign fibers can vary considerably, but hardly exceeds a length of 7 cm.

Packing material Cotton bales are often packed in polypropylene bags or other synthetic material after ginning. Other kind of packing material made of natural fibers will not be discussed here. Foreign fibers consisting of polypropylene are often white and therefore hardly detectable by electronic means. These fibers do not protrude and are not detected before dyeing or finishing. Thus, they first become visible in the dyed woven or knitted fabric.

Fig. 8-9

Examples of packing material / Single fiber of a colored polypropylene string for packing the cotton fibers / Distance between black lines: 1 cm

Dirtiness Dirtiness is caused of substances, which adhere to, are spun into or have penetrated into the yarn body. The contamination of bales is usually attributed to transport damage, improper storage and print color. In the spinning mill, dirtiness as a foreign matter can be caused by •

lubricant residue on machine parts (grease or oil)

•

a messy working environment with dust and dirt

•

dust or very small particles from rubberized machine parts (e.g. press rollers) or drive belts, which adhere to the yarn

•

Transport vehicles which were not cleaned when moving cotton.

In the yarn, dirtiness appears mostly as dark, brown or gray contaminants. In contrast to many foreign fibers or packing materials, such faults are often very long, for example 5 cm or more. Due to the length and the missing fibrous structure, these faults can usually be clearly identified.

8.6

USTER® QUANTUM 3

Foreign fibers

Fig. 8-10

8

Example of grease in the yarn

Vegetable matter With vegetable matter, it is necessary to clearly differentiate between two categories •

pieces of vegetables

•

vegetable packing material

Pieces of vegetables Under this term, it is commonly understood some fragments of: •

leaves

•

bark

•

stems

•

seed-coat fragments

The color is light to dark brown and the shape is irregular. The foreign matter adheres to or, in some cases, is embedded in the yarn. The frequency of such foreign matter depends on the degree of contamination of the fiber material and on the efficiency of the blowroom equipment. In general, it can be said that the relative percentage of such foreign matter is usually very high. Foreign matter in the form of vegetable fragments is normally brightened up almost completely in the bleaching process. But the effectiveness of the bleaching process depends on the recipe and on the applied technology. Under normal conditions, this type of foreign matter is considered as non-disturbing after correct bleaching. However, aggressive bleaching agents are not allowed anymore. Experience has shown that vegetables deriving from weeds might remain as dark spots in the yarn after bleaching. The monitoring of such faults is recommended.

Fig. 8-11

Examples of seed-coat fragments

USTER® QUANTUM 3

8.7

8

Foreign fibers

Vegetable packing material Foreign matter made out of vegetable packing materials is e.g.: •

jute fabric or jute-/hemp strings

•

chemical components based on cellulosic material

The structure of the material is clearly fibrous. The color is usually light to dark-brown and the length is in a short to medium range of approx. 1 to 2 cm. The fibers are extremely rigid and brittle, so that they often protrude from the yarn and rarely cling tightly to the yarn body. Due to the chemical similarity to the vegetable components of the fiber material, e.g. cotton, vegetable packing materials are also affected by the bleaching process, whereby the recipe and the process technology again play an important role.

Fig. 8-12

8.3.2

Examples for vegetables in the yarn

Degree of contamination of bales

The investigation of ITMF every second year in the past has shown that the degree of contamination of cotton bales depends very much on the growth area. Fig. 8-13 shows the growth areas with the most contaminated bales.

8.8

USTER® QUANTUM 3

8

Foreign fibers

Fig. 8-13

Growth areas with the highest foreign fiber contamination in cotton bales (Source: ITMF 2009)

Fig. 8-14 shows the growth areas with the least contaminated cotton bales.

Fig. 8-14

Growth areas with the lowest foreign fiber contamination in cotton bales (Source: ITMF 2009)

It has to be taken into consideration that those growth areas where cotton is harvested with machines are less affected by inorganic matter because there is less between workers and cotton, but the amount of vegetable can be higher.

USTER® QUANTUM 3

8.9

8

Foreign fibers

It is evident that while a distinction between “most contaminated” and “least contaminated” cotton can be made, there are no cotton varieties produced which have zero contamination. As can be seen above, at least 5% of the produced bales from even the least contaminated origins have significant levels of contamination.

8.3.3

Size and appearance of foreign matter in spinning mills

If foreign material cannot be eliminated prior to the card the foreign material is cut into pieces by the card. A piece of plastic can result in a number of individual foreign fibers after the card. As these fibers are mostly colored, the cluster of foreign fibers can easily be recognized in the card sliver. These clusters of foreign fibers will lead to human interventions, consequently loss of production efficiency and labor costs, because the clearers on the winding machines will trigger foreign fiber alarm due to the higher amount of foreign fibers within a short period. Often in some spinning mills some of the foreign fibers are added accidentally through human ignorance, waste recycling etc. which contaminate the cotton fibers during the spinning process. For such fibers the clearer as a monitoring system at the last stage of the spinning process is the only tool which can eliminate such fibers.

Removed foreign material in bale Opening & Cleaning Line Fig. 8-15

Card sliver

Card

Yarn

Drawframe

Spinning machine

Foreign material at various stages of the spinning process

The foreign fibers which cannot be eliminated during the spinning process will show up in the yarn and have to be eliminated by the yarn clearer on the winding.

8.10

USTER® QUANTUM 3

Foreign fibers

8.3.4

8

Frequency of foreign fibers in spinning mills

In order to understand the frequency of foreign fibers in spinning mills we have to consider that foreign fibers which exist as clusters in the card sliver are drawn several times in the spinning process until they show up in the yarn. The more steps in the spinning process the more increases the distance from foreign fiber to foreign fiber in the yarn. Therefore, the distance between two foreign fibers is longer in a ring spinning operation with combers than in an OE rotor operation. Assumption: Plastic film prior to card of 2 cm2. Resulting cluster: 400 individual foreign fibers in the card sliver (Fig. 8-15). OE rotor spinning

Ring spinning carded process

Ring spinning combed process

Cards

Cards

Cards

Drawframes

OE rotor spinning machines

Drawing ratio 1200 to 10'000

Drawframes

Roving frames

Drawing ratio 3000 to 30'000

Drawframes

Ribbon lap machines

Ring spinning machines

Combers

Winding machines

Drawframes

Drawing ratio 300'000 to 1'000'000

Roving frames

*0,2 to 1,5 m

*1 to 10 m

* Average distance between 2 foreign fibers

Ring spinning machines Winding machines

*100 to 300 m

Fig. 8-16

Effect of drafting on foreign fiber distribution in yarns

In Fig. 8-16 the processing steps and the drawing ratios are shown for the 3 most important spinning processes. It can be seen in the figure that the distance between two foreign fibers is short for short spinning processes and long for spinning processes with many steps.

USTER® QUANTUM 3

8.11

8

Foreign fibers

8.3.5

Foreign fiber risk calculated for a spinning mill

Fig. 8-17 shows the risk of a spinning mill which has the foreign fiber challenge not under control. 34800

36000 32000

Sales prices in USD

28000 24000 18000

20000 16000 12000 7320

8000 3840

4000 600

1320

0 Bale

Fig. 8-17

Yarn (Nec 30, combed)

Raw fabric

Finished fabric (bleached)

Shirts

Retailer

Foreign fiber risk calculated for a spinning mill

The calculation is based on a bale of 480 lbs (217 kg). The price for the bale was USD 600. The spinner’s sales price for yarns made of this bale was USD 1’320. The raw fabric was sold for USD 3’840. The finished fabric was sold for USD 7’320. The foreign fibers were only detected after bleaching. The finishing plant did not send the complaint to the cotton trader, but to the spinner. Therefore, the finishing plant had a damage of USD 7’320 per bale which had to be paid by the spinner, but the spinner only earned USD 600 for the processing of the entire bale. Therefore, a reliable foreign fiber elimination system has to be installed in the spinning mill if the spinner wants to be the master of his destiny. Any claims to the spinner are much higher than the actual cost of spinning since there is a significant value addition along the chain.

8.4

Classification matrix of foreign fibers with the USTER® QUANTUM 3

Uster Technologies has developed a classification matrix for foreign fibers and vegetable matters. Fig. 8-18 shows the structure of the classification matrix for foreign fibers, which represents the appearance (in %) and length (in cm). The appearance corresponds to the visibility of a fault.

8.12

USTER® QUANTUM 3

8

Foreign fibers

Fig. 8-18

Classifying system for foreign fibers (Standard F classes (left) and extended F classes(right))

This matrix was developed in a similar way as Uster Technologies designed the matrix for thick places and thin places. A considerable amount of foreign fibers are located in the B1 class. Therefore, the B1 class (B11 to B14) serves as a benchmark for recognizing the degree of contamination of the raw material. The experience values are the following: Yarn type

Low degree of contamination per 100 km

Heavily contaminated per 100 km

Combed yarns, 100% cotton

10

150

Carded yarns, 100% cotton

20

300

Worsted yarns, 100% wool

20

100

8.5

Table 8-2 Benchmarks for foreign fibers

Clearing limits

The setting of the foreign fiber channels depends highly on the application profile of the yarn and the amount of foreign fibers in the raw material. Basically, it can be said: the longer a foreign fiber and the higher its color intensity: •

the more disturbing are the consequences in the fabric

•

the lower is the number of this kind of faults in the yarn

As for regular yarn clearing, it is also valid for foreign fiber clearing: •

More sensitive setting: more splices, but less remaining faults in the yarn

•

Less sensitive setting: many remaining faults, but less splices

As for normal yarn clearing, it can also be said that foreign fiber clearing is a compromise between quality and productivity.

USTER® QUANTUM 3

8.13

8

Foreign fibers

8.5.1

General references for foreign fiber clearing

Fig. 8-19 illustrates the relationship between the visual appearance and the length of foreign fibers. The normal position for typical foreign fibers in a cotton yarn is shown. The limit between the diverse foreign fibers cannot be drawn clearly and they also overlap partly.

Fig. 8-19

Distribution of foreign fibers in a cotton yarn

•

Vegetables: - are mainly in short length ranges - occur in the whole intensity spectrum from low to high - should not be cleared, if possible, as they are possibly removed or neutralized in the following processes, particularly during the bleaching process

•

Foreign fibers: - are mostly shorter than 7 cm, but thinner than vegetables - must be cleared when exceeding the clearing limit

8.5.2

Clearing limits for dark foreign fibers in light yarn

The FD-channel (Foreign matter Dark) is responsible for the clearing of dark foreign fibers in light yarn. A dark foreign fiber has a low light reflection and, therefore, appears darker than the yarn.

8.14

USTER® QUANTUM 3

Foreign fibers

8.5.3

8


Analogous to the optimization of the thick and thin places, the setting for the foreign fiber clearing must also be started with the standard settings. According to the results, further adjustments have to be carried out. Fig. 8-20 describes this standard procedure when starting foreign fiber clearing with unknown cotton:

Fig. 8-20

Diagram for the optimization of foreign fiber clearing

USTER® QUANTUM 3

8.15

8

Foreign fibers

Foreign fibers of different origin, composition, structure and color can be detected with foreign fiber clearing. By selecting a limit only the disturbing foreign fibers are removed from the yarn. By using FD, dark foreign fibers in light yarn are detected during production. The setting of foreign material is mainly driven by the production lines in a mill; of course also in blended or synthetic yarn the foreign material caused by fly or mix up can be eliminated. Fig. 8-21 shows the clearing limit as shown in the setting window of the control unit. The USTER® QUANTUM 3 gives us the chance of determining our clearing limits by placing a maximum of 8 set points FD1 to FD8. In Fig. 8-21, we can see 3 setting points (red rectangle) and the clearing limit for FD foreign fibers. By this setting method the effects of a change of the parameters on the clearing limit can be demonstrated directly. As soon as we enter new values at set point, the next one will appear until we reach the 8th set point. This means after we entered the values for FD1, set point FD2 will appear and it will continue the same way.

Fig. 8-21


Set points have two parameters. These are: sensitivity (%) and reference length (cm).

Intensity The sensitivity (%) is a parameter for the clearing limits of the corresponding fault channel. The sensitivity setting shifts the clearing limit upwards (less sensitive) or downwards (more sensitive). (FD1= 40%, Fig. 8-21).

Reference length The reference length (cm) is a parameter for the clearing limits of the corresponding fault channel and shifts the clearing limit to the right (less sensitive) or to the left (more sensitive) (FD1 = 0.6 cm, Fig. 8-21).

8.16

USTER® QUANTUM 3

Foreign fibers

8.5.4

8

Setting a smart clearing limit for dark foreign matter (FD)

As we mentioned in the previous chapter, the dense area is the display of the range where foreign fibers are occurring very frequently. This display of the dense area helps the to set a clearing limit easier with an optimal balance between quality and productivity (Fig. 8-22). Similar to the yarn body, after running only a few kilometers of yarn, the first impression of the dense area and the events will appear. In order to see the dense area, the should press the dense area key (Fig. 8-23). Besides the dense area, also the scatter plot of the cut faults and remaining events, and the number of expected fault cuts per 100 km together with the used setting limits will appear directly on the same setting page (Fig. 8-24). Pressing key presents • The dense area. • Scatter plot of the cut faults and remaining events. • Number of expected fault cuts / 100 km. Clearing limit Red dots = cut yarn faults. Blue dots are remaining events Dense area = Proposes the starting point for the clearing limits based on the dense area.

Fig. 8-22

Display of the dense area

With the USTER® QUANTUM 3, we have a very useful and smart tool to find the right starting point for the new clearing limits. The Smart Limit function proposes a starting point for the clearing limits based on the yarn body and also provides a cut forecast to facilitate faster setup of clearing limits. The setting of USTER® QUANTUM 3 can be done simply in one step (Fig. 8-23, Fig. 8-24):

Fig. 8-23

Setting page for FD manual setting or setting by smart limits available

USTER® QUANTUM 3

Fig. 8-24

Display of dense area

8.17

8

Foreign fibers

After pressing the smart limit key, a small window with the two appropriate keys to adapt and optimize the smart limit for foreign fibers appears (Fig. 8-25). The Smart Limit has been developed to propose a starting point for the clearing limits by pressing one button. This proposal can be altered by up and down keys to optimize the settings according to the individual quality requirements and productivity. Every change of setting will automatically initiate a new calculation of the cut forecast. It is recommended to use the Smart Limit function after a minimum of 30 km of yarn has already been wound. This length includes all the clearers of the machine.

The new setting point proposals = Smart Limit 1 step less sensitive. = Smart Limit 1 step more sensitive. =

Show dense area and scatter plot

= confirm and activate optimized clearing limit. = cancel all modifications

Fig. 8-25


Besides the smart limit function, of course the foreign fiber (FD) and vegetable matter clearing (VEG) classification is still a very powerful tool where we can refer our last decision (Fig. 8-26). Cuts/100km Total yarn events /100km

Fig. 8-26

8.18

FD online classification

USTER® QUANTUM 3

Foreign fibers

8

The red figure in each class indicates how many foreign fibers were eliminated by the clearer within this class and the black figure represents the number of foreign fibers which were detected in the class.

8.6

Foreign fibers and their effect on the various production processes

What is understood by foreign fiber detection? Commonly, under the term “foreign fiber detection”, textile specialists understand the elimination of all foreign matter in a yarn, which exhibits a contrast to the yarn. With the existing technology, a real color measurement is not possible. Therefore, the evaluation of the light/dark contrast was chosen. Very short foreign fibers with the same extension like seed coat fragments must be left in the yarn as they are not disturbing and because of the high number of cuts that has to be expected and because such fibers can hardly be recognized in a fabric. The decision for the respective clearing limit must derive from the principle that no long foreign fibers should remain in the yarn. The maximum issible length of the foreign fibers which may remain in the yarn depends on the final purpose of the yarn. Particularly critical are unicolored large fabric such as bed sheets, table sheets, etc.

Measuring principle and evaluation For the monitoring of foreign fibers, an optical measuring system is used. For this, a comparison between the reflection deviation of the foreign fiber and the normal yarn color is measured. This means, that a very dark foreign fiber in a very light yarn produces a higher contrast than the same foreign fiber in a yarn made out of gray fibers. The difference between the actual yarn color and the contrast of a foreign fiber and its length, over which the color change occurs, is measured. These two values (reflection in % and length in cm) are compared with the set clearing limits. Are both values above the clearing limit, a cut is carried out. Foreign fibers which do not exceed the clearing limit are entered in the classification matrix.

Structure of the classification matrix Fig. 8-27 shows the structure of the classification matrix for foreign fibers. The foreign fibers are classified by the parameters reflection (%) and length (cm).

USTER® QUANTUM 3

8.19

8

Foreign fibers

Fig. 8-27

Structure of the classification matrix for foreign fibers

Fig. 8-28 shows a practical example for a classification matrix of a carded cotton yarn.

Fig. 8-28

Practical example for a foreign fiber matrix

Foreign fiber grades The graphical representation of disturbing foreign fibers and their classification cannot be done the same way as for disturbing thick and thin places, i.e. as generally accepted grades. Depending on the degree of contamination of the raw material, certain colors and frequencies can dominate in the cotton from certain growth areas, whereas other growing regions have completely different foreign fibers. Therefore, it is recommended to generate such grades depending on the respective fiber blend internally, in order to obtain certain standards for the existing foreign fibers.

8.20

USTER® QUANTUM 3

Foreign fibers

8.6.1

8

Methods to eliminate foreign material and frequency of foreign material

A comparison of frequency of foreign material and elimination methods Fig. 8-29 shows the domains of foreign material removal systems and the frequency of foreign material. It is obvious that the frequency of foreign material increases considerably in the area of fine foreign matter (human and animal hair, plastic fibers, fragments of strings, seed coat fragments). Frequency of foreign material

Domain of yarn clearers Domain of manual removal Domain of automatic removal systems prior to card

Fig. 8-29

0,001

0,01

(diameter 10µm)

(diameter 100µm)

0,1

1,0

10 cm2

Size of foreign material

Methods to eliminate foreign material in cotton and foreign material frequency

It is evident that the type and frequency of foreign matter require an effective system to combat this problem. Over the years spinning mills used the following methods to eliminate disturbing foreign matter in order to keep the defects within acceptable limits: •

Selection of cotton with small amount of foreign fibers

•

manual labor to pick foreign matter in cotton prior to the opening

•

foreign matter removal systems prior to the card

•

foreign fiber clearers on winding machines

In some cases, especially in vertically integrated textile mills, the mending of defects after finishing the fabric is also common practice, but only part of the foreign fibers can be extracted from the fabric.

Cotton selection It makes sense in a spinning mill to know the growth areas with low foreign material contamination. It must be the aim to order cotton from areas with a low number of foreign material content to keep the risk of remaining foreign fibers low and to improve the efficiency of the removal systems both human and electronic. Further, they help to keep the number of foreign fiber cuts with the clearer on a low level. This is especially valid for end customers who ask for “zero foreign fibers” as a mandatory requirement, and where a significant is paid for such a high value addition. If the which the spinner can realize is not significant, choosing low contamination cotton can often lead to other issues seriously affecting profit margins.

USTER® QUANTUM 3

8.21

8

Foreign fibers

This may be cotton with higher nep content, higher short fiber content and higher cotton prices. Further, cotton supply contracts in general do not include contamination level as a dispute clause, with the result that losses cannot be recovered in case contamination expectations are not met.

Manual labor In developing countries, low labor costs allow use of manual inspection of cotton to remove the major defects. Typically mills use manual labor to open bales, inspect for contamination and repack them again. The number of people or the work load employed varies from mill to mill and the end use. Estimates from spinning mills in China show between 1 person per 1 to 3 bales per day depending on the quality demand. Therefore, in an average size spinning mill with 30’000 spindles the number of employees who do these jobs vary from 60 to 180 people.

Fig. 8-30

Manual removal of foreign material in a Chinese spinning mill

Foreign material removal systems prior to the card There are various foreign material removal systems available today prior to the card. In general such devices are important to eliminate the foreign matter of a size greater than 0.5 cm2 to avoid further disintegration into finer fibers which would increase the cuts in the final inspection by the yarn clearers. However, such systems do not fully meet the quality targets of the end since the size and the number of ejections make it practically impossible to eliminate the single foreign fibers which constitute the highest amount of disturbing defects in the final yarn or fabric. Further, the location of the system and the size of the tuft play a decisive role for the detection efficiency. Similar to manual elimination, the electronic removal systems help in reducing major contaminations, finally reducing cuts and human intervention in winding. This helps to maintain consistency in cuts.

Foreign fiber clearers in winding Foreign fiber clearers are by far the most efficient systems to solve the contamination problems. With the improvement of the detection rate by the USTER® QUANTUM 3, the solution has become more and more popular. Today about 75% of delivered clearers are with foreign fiber functionality for cotton yarn measurement.

8.22

USTER® QUANTUM 3

8

Foreign fibers

Since the clearers are integrated in the automatic winder, they are in a position to make the final inspection and monitor every millimeter of yarn. Further, the clearers are today capable of detecting the finest defects not clearly visible to the naked eye. However, many of these very fine fibers may be visible after subsequent processes such as bleaching, dyeing, etc. This includes white and transparent polypropylene defects. The clearer can replace each disturbing defect with a splice, thereby eliminating the defect from the final package to the weaver or knitter. Fig. 8-29 is, therefore, a very important figure to understand the mechanism of foreign material. This figure also shows that the foreign material removal systems prior to the card have little influence on the cut rate of the clearers, because most of the foreign fibers which are eliminated by the clearers cannot be recognized by systems prior to the card. It also has to be taken into consideration that the automatic foreign material elimination systems prior to the card eject a considerable amount of cotton together with the foreign materials which must be separated manually from the “real” foreign materials to keep the waste on a reasonable level.

Fig. 8-31

Contaminations found in cotton

Calculation of a practical example: Assumption: Spinning mill with 30‘000 spindles Production per day: 15’000 kg Yarn count: Nec 30 Subject Ejections prior to card per opening/cleaning line

Calculation method

Result

1200/24 hours

960 foreign items

Efficiency 80% Ejections prior to card Number of foreign fiber cuts on the winding machine Winding speed: 1400 m/min Foreign fiber cuts per winding position and per day Number of foreign fiber cuts with 600 winding positions Table 8-3

2 opening/cleaning lines

1920 foreign items

1/100 km

25 per 100 km of yarn

Winding duration per 100 km: 100’000 / 1’400

71,43 min

25 • 1440 / 71,43

504 cuts

600 • 504

302’400 cuts

Calculation of foreign material detection

USTER® QUANTUM 3

8.23

8

Foreign fibers

Conclusion per 24 hours, entire mill: Ejection of real foreign matter:

1920

Number of foreign fiber cuts:

302’400

This calculation clearly indicates that the number of foreign fiber cuts by the clearer is more than 100 times higher than the number of ejections by the foreign fiber removal system prior to the card. This also explains that the number of small foreign items is much higher than the number of large particles which can be eliminated prior to the card. If the foreign material removal system prior to the card is switched off, it does hardly affect the number of clearer cuts for the same reason. However, the foreign matter removal systems prior to the card can avoid that large foreign particles are cut in hundreds of fibers which later requires a human intervention to eliminate the foreign fiber clusters in the card sliver or to replace the affected roving in case of a foreign fiber alarm of the clearer.

Mending of defects in weaving/knitting Mending of the woven fabric by removing the disturbing foreign fibers is also a common practice, especially in composite mills. However, as a practice this is possible only if the defect frequency is low. Further, this also results in costs and claims to the spinner. Some estimates mention USD 6 to 10 / 100 m as mending costs in low cost countries depending on the amount of defects. For knitted fabrics, mending is not recommended since they damage the fabric. Defects that have a higher defect rate or mending requirement are often sold for other low end applications, e.g. printed furnishing.

8.6.2

Effect of large foreign particles on the spinning process

If the foreign material removal system prior to the card is not in a position to eliminate larger foreign particles because the particles are embedded in a tuft, the card will produce a large number of individual foreign fibers which form a cluster in the card sliver as mentioned above. After various drawing processes they will end in the yarn. The frequency depends on the number of drawing processes as mentioned above in Fig. 8-16.

8.6.3

Alarm options for frequent foreign fibers in yarns with clearers

The following are the methods to eliminate clusters of foreign fibers:

Ring spinning Recognition with foreign fiber alarm. If the number of foreign fiber counts oversteps a preset threshold the winding machine triggers the red light at the critical winding position which also needs a human intervention or the winder automatically ejects the contaminated bobbin.

8.24

USTER® QUANTUM 3

8

Foreign fibers

8.6.4

Limits of foreign fiber elimination

Ring spun yarn Table 8-4 shows an average number of splices in a ring spinning operation. This mill eliminates 30 foreign fibers per 100 km. The total number of splices is 92,5 per kilometer. At a winding speed of 1200 m/min the mean time between 2 splices per winding position is 0,9 minutes. Assumption: Count Nec 30, combed cotton, bobbin size 70 g, winding speed 1200 m/min. All figures calculated per 100 km. Bobbin changes

28,5

"Natural" end breaks

4,0

Thin and thick places

30,0

Foreign fibers

30,0

Total number of splices

92,5

Mean time between 2 splices per winding position

0,9 min

Table 8-4 Limits of foreign fiber elimination on winders

With 0,9 minutes between two splices we are approaching the limit of issible stops on the winding machine. It is not recommended to process heavily contaminated cotton and expect afterwards that the clearer can produce a yarn which is completely free of foreign fibers.

8.6.5

Process disturbances while beaming, weaving and knitting caused by foreign matter

Table 8-5 shows the influence of remaining foreign fibers in yarns on subsequent processing stages in the textile chain. Process

Benchmarks for end breaks (Central Europe)

End breaks caused by foreign matter (experience values)

Beaming

0.2 to 0.3 per 1'000'000 meters

up to 50%

Weaving

1 to 2 per 100'000 picks

up to 50%

Knitting

1 to 2 per hour

up to 40%

8.6.6

Table 8-5 Experience values / end breaks in beaming, weaving, knitting caused by foreign matter

Recommended approach to eliminate foreign fibers

Based on the discussions in this paper, the following approach is recommended for elimination of foreign fibers: •

Foreign fiber clearers are mandatory to eliminate foreign fibers, to fulfill the end quality needs and to assess the overall cotton quality (using classification figures)

USTER® QUANTUM 3

8.25

8

Foreign fibers

•

Installing automatic detection systems prior to the card helps in reducing manpower, eliminating major defects to reduce stoppages, to reduce human intervention and to maintain consistency in FF clearing

•

Random manual inspection of cotton batches helps to identify and track the type and amount of defects in order to optimize purchase decisions

•

Importing cleaner cotton helps to fulfill demands for a cotton yarn with small amount of foreign fibers

To prove the above approach Uster Technologies conducted a trial in a Chinese Spinning Mill. The following is the description and results of the field trials.

8.6.7

Field tests in China

Test procedure A field test was carried out in a quality oriented Chinese spinning mill, where the following foreign matter removal systems were available: •

Electronic foreign material elimination system prior to the card

•

Visual elimination of foreign material prior to the card (70 employees)

•

Yarn clearer (USTER® QUANTUM 3) with foreign fiber feature.

The mills had the following standards: •

Knitted fabric - 10 defects/ 20 kg

•

Woven fabric – 28 defects / 100 square yards

Four tests were carried out to check the efficiency of the three above mentioned elimination systems. The final packages were sent for weaving (as weft) and knitting (circular knitting machine). The tests were carried out in a mill where the yarn was woven and knitted. Afterwards, textile experts checked each of the trial fabrics and counted the remaining foreign fibers in the fabrics. All defects that were disturbing were counted. This means that very short defects were included as well, though they were beyond the clearing limits. Dirt was not considered since it disappears in subsequent processes.

The yarn produced was a Ne 32/1 (18,7tex), produced from mainly Xinjian province, but also included some imported cotton from Benin, Zimbabwe and Uzbekistan. The daily production of this mill is about 22 tons of ring spun yarn.

8.26

USTER® QUANTUM 3

Foreign fibers

8

Knitted fabrics This mill sells knitted fabrics as first grade if the number of foreign fibers in a knitted fabric of 20 kg weight is less than 10. The weight of 20 kg is equivalent to a length of the knitted fabric of 120 m. A first test was made without any foreign material elimination systems. The fabric was knitted on a 30” circular knitting machine, 96 feeders, fabric weight 125g/ 75cm. The fabric inspection experts could find 49 foreign fibers in the grey knitted fabric of 20 kg (Fig. 8-33).

Fig. 8-32

Fabric inspection for foreign fibers at Litay

A second test was carried out with a visual check of the raw material and simultaneously with an electronic elimination system prior to the card. With these two elimination methods, the amount of foreign fibers which the experts counted in the knitted fabric dropped from 49 (without any elimination system) to 38 (Fig. 8-33). Number of foreign fibers 50 49 40 38 30 20 Tolerated limit: 10 foreign fibers

10 0 Without removal systems

Fig. 8-33

Visual check and removal system prior to card st

Test result with knitted fabrics, Litai Ne 32, 1 grade < 10 defects / 20 kg of knitted fabric

A third test was made by using the USTER® QUANTUM clearer only. The number of foreign fiber cuts of the clearer was 30 to 35 per 100 km. The visual check of the grey knitted fabric has resulted in 8 foreign fibers remaining (Fig. 8-34).

USTER® QUANTUM 3

8.27

8

Foreign fibers

Number of foreign fibers 50 49 40 30 20 Tolerated limit: 10 foreign fibers

10 8 0 Without removal systems

Fig. 8-34

With yarn clearer only

Comparison with the efficiency of the yarn clearer only

A fourth test was undertaken with all the elimination systems. After knitting of a roll with 20 kg, the experts counted 6 remaining foreign fibers (Fig. 8-35). Number of foreign fibers 50 49 40 30 20 Tolerated limit: 10 foreign fibers

10 6 0 Without removal systems

Fig. 8-35

With removal systems prior to card and yarn clearer

Application of all elimination systems

Conclusion It was only possible to reduce the amount of foreign fibers below the given threshold of 10 per 20 kg of knitting with the USTER® QUANTUM clearer because the clearer is the only tool which can also detect and eliminate small foreign fibers. If this figure has to be improved, the number of foreign fiber cuts of the clearer per 100 km has to be increased.

8.28

USTER® QUANTUM 3

Foreign fibers

8

Woven fabrics This mill also sells woven fabrics as first grade if the number of visually counted foreign fibers in a woven fabric of 100 square yards is below 28. A first test was made without any foreign material elimination systems (Fig. 8-36). The experts could find 56 foreign fibers in the grey woven fabric of 100 square yards. A second test was carried out with a visual check and simultaneously with an electronic elimination system prior to the card. With these two elimination methods the amount of foreign fibers which the experts counted in the woven fabric dropped from 56 (without any elimination system) to 52 (Fig. 8-36).

Fig. 8-36

st

Test results with woven fabrics, Litai Ne 32, 1 grade < 28 defects / 100 square yards

A third test was made by using the USTER® QUANTUM only. The number of foreign fiber cuts of the clearer was 30 to 35 per 100 km. The visual check of the grey woven fabric has resulted in 26 foreign fibers (Fig. 8-37). Number of foreign fibers 60 50

56

40 30 26

20

Tolerated limit: 28 foreign fibers


Fig. 8-37

With yarn clearer only

Comparison with the efficiency of the yarn clearer only

USTER® QUANTUM 3

8.29

8

Foreign fibers

A fourth test was undertaken with all the elimination systems. The experts counted 16 remaining foreign fibers per 100 square yards (Fig. 8-38). Number of foreign fibers 60 50

56

40 30

Tolerated limit: 28 foreign fibers

20 16


Fig. 8-38

With removal systems prior to card and yarn clearer

Application of all elimination systems

Conclusion It was only possible to reduce the amount of foreign fibers below the threshold of 28 per 100 square yards with the USTER® QUANTUM clearer because the clearer is the only tool which can also detect and eliminate small foreign fibers. If this figure has to be improved, the number of foreign fiber cuts of the clearer per 100 km has to be increased.

8.7

Foreign fibers and their effect on the fabric appearance

Depending on the application of the yarn, a foreign fiber can have different effects on the woven or knitted fabric. In knitting, the loop formation causes a shortening of the yarn, including the foreign fiber, which leads to a concentration of the color contrast. This means, that short foreign fibers have a more disturbing effect than in a knitted fabric. Short foreign fibers protrude from the woven fabric, unless it exhibits a high density and stiffness. Only a combination of the intensity and the length of a foreign fiber have a disturbing effect on the eye. In the following figures (Fig. 8-39 and Fig. 8-40) examples for foreign fiber in a woven and in a knitted fabric are shown.

8.30

USTER® QUANTUM 3

Foreign fibers

Fig. 8-39

Example of a foreign fiber in a woven fabric

Fig. 8-40

Example of foreign fibers in a knitted fabric

USTER® QUANTUM 3

8

8.31

8

Foreign fibers

In general, 4 – 5 disturbing foreign fibers are accepted in a piece of knitted fabric (about 80 – 120 m) today. As disturbing are regarded: •

Short, clearly visible colored foreign fibers in a range of 2 to 3 loops

•

Longer, light foreign fibers starting in a range of 8 to 10 loops

Fig. 8-41 to Fig. 8-46 show foreign fibers in various garments. The zoomed pictures show different colored foreign fibers. In Fig. 8-41 and Fig. 8-42, a blue colored foreign fiber can be observed. The garment was produced with 100% cotton and, after the bleaching process, it had a uniform white color. But the blue colored foreign fiber disturbs the knitted fabric appearance.

Fig. 8-41

Foreign fiber in knitted garment / 100% cotton, combed, Nec 46 (13 tex)

Fig. 8-42


In Fig. 8-43 and Fig. 8-44, a red colored foreign fiber can be observed. The garment is produced with 100% cotton, and, after bleaching process, it had a white color. But the red colored foreign fiber disturbs the knitted fabric appearance.

Fig. 8-43

8.32


Fig. 8-44


USTER® QUANTUM 3

8

Foreign fibers

Fig. 8-45 and Fig. 8-46 show a blue colored foreign fiber in men’s cardigan. The product was produced with 100% combed cotton.

Fig. 8-45

8.7.1

Foreign fiber in men’s cardigan / 100% cotton, combed, Nec 28 (21 tex)

Fig. 8-46

Foreign fiber in men’s cardigan / 100% cotton, combed, Nec 28 (21 tex)

Reasons and measures to minimize foreign fibers in yarns

In Table 8-6 and Table 8-7, the origin of the faults related to yarn contaminations is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. CONTAMINATION Origin of Faults


Bale management

Prefer – when possible – to use cotton with low content of foreign fibers. Sometimes spinning mills tend to create or intensify the contamination problem. A popular mistake is the use of plastic bags for the waste collection and transportation inside the spinning mill.

Blowroom

Controlled recycling of waste

Cards

Efficient carding and combing

Drawing frame

Proper blending at all drawframes

Combing

Optimize comber settings (comber noil, processing speed) in order to achieve the maximum foreign fiber reduction.

Table 8-6

USTER® QUANTUM 3

8.33

8

Foreign fibers

®

CONTAMINATION / USTER Tools for Improvement Tools

Improvement ®

®

Quality control of foreign fibers with USTER TESTER when dealing with new raw material

®

Proper setting of foreign fiber detection


Separate outlier bobbins with too many foreign fibers with quality alarm settings ®


8.34

Long-term control of quality level

Preventive measures and tools for the management of foreign fibers

USTER® QUANTUM 3


9


9.1

Introduction

9

Uster Technologies has now many years of foreign fiber experience with USTER® QUANTUM. This experience helped us to recognize opportunities to improve the features of the USTER® QUANTUM 3. Some of the customers are also interested to eliminate vegetables, but many customers are eager to only remove real foreign fibers because they can prove that the vegetables are not visible anymore after bleaching.

The elimination of inorganic foreign fibers only and keeping as much vegetables in the yarn as possible can be applied for the following purposes: •

Reduction of cuts while keeping the eliminated number of disturbing foreign fibers constant

•

Keeping the number of cuts constant but eliminating more and finer foreign fibers with the same machineefficiency.

Uster Technologies has developed a tool for the USTER® QUANTUM 3 to separate foreign fibers and vegetables. This feature is named Vegetable Clearing. The new foreign matter (FM) sensor of the USTER® QUANTUM 3 has multicolored light sources and can detect various colored foreign fibers and also enables the classification of vegetables separately. The USTER® QUANTUM 3 smartly splits the foreign matter into two populations, disturbing colored inorganic foreign fibers and non disturbing vegetable foreign matter. Separate limits for foreign fibers and vegetable matter can be defined.

Fig. 9-1

Various vegetable matters in yarns at different magnification. The distance between the black lines is 10 mm

USTER® QUANTUM 3

9.1

9


9.1.1

Vegetable matter

With vegetable matter, it is necessary to clearly differentiate between two categories •

pieces of vegetables

•

vegetable packing material

Pieces of vegetables Under this term, it is commonly understood: •

leaf fragments

•

bark fragments

•

stem fragments

•

seed-coat fragments

The color is light to dark brown and the shape is irregular. The foreign matter adheres to or, in some cases, is embedded in the yarn. The frequency of such foreign matter depends on the degree of contamination of the fiber material and on the efficiency of the blow-room equipment. In general, it can be said that the relative percentage of such foreign matter is usually high. Foreign matter in the form of vegetables is normally brightened up almost completely in the bleaching process. But the effectiveness of the bleaching process depends on the recipe and on the applied technology. Under normal conditions, this type of foreign matter is considered as non-disturbing. Experience has shown that vegetables deriving from some weeds might remain as dark spots in the yarn after bleaching. The monitoring of such faults is aspired.

Fig. 9-2

Examples for seed-coat fragments (left) and short vegetables (right) in yarns

Vegetable packing material Foreign matter made out of vegetable packing materials is e.g.: •

jute fabric or jute or hemp strings

•

chemical components based on cellulosic material

9.2

USTER® QUANTUM 3


9

The structure of the material is clearly fibrous. The color is usually light to dark-brown and the length is in a short to medium range of approx. 1 to 2 cm. The fibers are extremely rigid and brittle, so that they often protrude from the yarn and rarely cling tightly to the yarn body (Fig. 9-3). Due to the chemical similarity to the vegetable components of the fiber material, e.g. cotton, vegetable packing materials are also affected by the bleaching process, whereby the recipe and the process technology again play an important role. Usually, this type of foreign matter can only be partly brightened through bleaching.

Fig. 9-3

9.1.2

Examples for long vegetables in yarns

Distribution of vegetables and foreign fibers

In order to differentiate between vegetables and foreign fibers, different possibilities were tested. The chosen approach was: •

A fine foreign fiber has a low reflection and a low mass

•

A coarse foreign fiber or a bundle of foreign fibers has a high reflection and a considerable mass

The vegetable matter clearing was developed only for the capacitive clearer.

9.2

Dense area for vegetable matter (VEG)

The “Dense Area”, an innovative and unique feature of the USTER® QUANTUM 3 has already been explained for foreign matter in Chapter 8. The USTER® QUANTUM 3 has a similar dense area for vegetable matter clearing. The dense area for vegetable matter is also the display of the range where vegetable matters are occurring very frequently. The brown colored dense area is used to visualize the distribution and frequency of clearing limits for the vegetable matter.

USTER® QUANTUM 3

9.3

9


The dense area depends on the raw material. If a yarn produced from cotton having a lot of foreign matter and vegetables, then the dense area will be wider, and a high number of cuts have to be expected. Similar to the yarn body, after running only a few kilometers of yarn, the first impression of the dense area and the significant foreign fibers will appear. Fig. 9-4 shows a dense area for inorganic foreign matter with vegetable clearing and Fig. 9-5 shows a dense area for vegetable matter with larger vegetables shown as single dots as seen by the USTER® QUANTUM 3, with all the frequent events recorded in the yarn (brown dots), and with the dense area of insignificant events (brown area). The vertical scale represents the visual appearance or intensity and the horizontal axis represents the vegetable faults length in cm.

Fig. 9-4

Display of the dense area and the scatter Fig. 9-5 plot for foreign matter (inorganic matter only)

Display of the dense area and the scatter plot for organic matter only

As shown in Fig. 9-6, two separate limits for inorganic fibers and vegetable matter are shown on the vegetable clearing page. The brown dots between the FD and vegetable clearing curves represent in cuts savings.

Fig. 9-6

9.4

Separate limits for inorganic fibers and organic matter

USTER® QUANTUM 3


9

Fig. 9-7 shows how the foreign matter can be separated into inorganic foreign fibers and vegetable matter.

Scatter plot containing inorganic and vegetable matter (FD Clearing)

Scatter plot containing only inorganic fibers (VEG Clearing)

Matrix of foreign matter showing clearing curve for inorganic matter (VEG Clearing)

Fig. 9-7

Scatter plot containing only vegetable matter (VEG Clearing)

Matrix of vegetable matter showing both clearing curves for inorganic and vegetable matter (VEG Clearing)

Separation of inorganic and vegetable matter

USTER® QUANTUM 3

9.5

9


9.3

Classification matrix of vegetable matters with the USTER® QUANTUM 3

Uster Technologies has developed a classification matrix for foreign fibers and vegetable matters. Fig. 9-8 shows the structure of the classification matrix for foreign fibers, which represents the appearance (in %) and length (in cm).

Fig. 9-8

9.4

Classifying system for vegetables (Standard vegetable classes (left) and extended vegetable classes (right))

Clearing limits

As a result of intensive field tests, the vegetable clearing was defined. Vegetables are part of foreign matter. However with most common bleaching processes, vegetables become invisible after bleaching. Therefore mostly it is not necessary to remove them. Since the proportion of vegetables is rather high in cottons of some growth areas this results in a substantial drop in production if all the larger vegetables have to be removed and at the same time limits the ability to remove inorganic disturbing fibers. The USTER® QUANTUM 3 separates vegetables from other foreign matter. This offers better selectivity in foreign matter clearing and save cuts significantly. The reduction of cuts is reached by allowing vegetables which will not disturb the downstream process to (they will not be cut). The feature is used for articles that will undergo a bleaching process. In most situations vegetables are not disturbing. However long and thick vegetables have to be removed since they can cause breaks in downstream processes. The Vegetable Clearing is a very useful tool to distinguish between organic and inorganic fibers. Since vegetables are not visible after the bleaching process, they can often remain in the yarn. The result is a reduction of foreign fiber cuts. There might be a need to cut long or intense vegetables to avoid warping or knitting breaks in subsequent processes.

9.6

USTER® QUANTUM 3

9


Fig. 9-9

Cut savings with vegetable clearing. The colored area between the two clearing curves shows the cut savings when applying Vegetable Clearing (right).

In applications where the bleaching agents are milder, vegetables do not completely disappear for the human eye after bleaching and need to be treated like colored foreign fibers. Therefore they have to be removed according to the quality needs.

9.4.1

Setting a clearing limit for vegetable matter (VEG)

The built-in intelligence of USTER® QUANTUM 3 divides the vegetables into more or less disturbing events according to the end product requirements. This is expressed by the way of choosing close, medium and open setting. The USTER® QUANTUM 3 has a vegetable Clearing feature displaying a dense area and four different setting possibilities. These are named FD switched off, close, medium and open. The USTER® QUANTUM 3 also provides vegetable classification. Three clearing limit possibilities (close, medium, open) are always synchronized to the FD clearing limit. The difference between the FD and vegetable clearing results in cut savings. •

As FD: The vegetable clearing is switched off. (All the vegetables are classified as foreign matter and they are removed by using FD clearing limit.)

•

Close: Only small vegetables remain in the yarn. Of course this will only result in a small saving of FD cuts.

•

Medium: Small to medium vegetables remain in the yarn. This will reduce the number of FD cuts to a large extend.

•

Open: Most of the vegetables remain in the yarn and the highest savings of cuts will be reached.

The Vegetable Clearing is only available when using the capacitive clearer. The USTER® QUANTUM 3 provides Vegetable Clearing with a dense area and three setting possibilities.

USTER® QUANTUM 3

9.7

9


Fig. 9-10 FD setting only

Fig. 9-14 Vegetable settings “close”

Fig. 9-11 Vegetable settings “close”

Fig. 9-12 Vegetable settings “medium”

Fig. 9-15 Vegetable settings “medium”

Fig. 9-13 Vegetable settings “open”

Fig. 9-16 Vegetable settings “open”

For each group or winding position the VEG events are displayed as individual dots on the classification matrix.

VEG clearing limit Brown dots are remaining vegetables. Dense area

Fig. 9-17

9.8

Display of the dense area and Vegetable Clearing curve. In the top right corner of the matrix the FD cuts saved are displayed.

USTER® QUANTUM 3


9

Recommendations: Generally, we are recommending using “medium” level, if the used raw material (cotton) contains vegetables. If the is sure that the used raw material does not contain any vegetables, then the vegetable clearing feature should not be used. For other raw material types like synthetics or worsted yarns the use of this function is not recommended.

Besides the clearing limit function, of course the foreign fiber (FD) and vegetable matter clearing (VEG) classification is a very powerful tool to minimize the number of cuts.

Fig. 9-18

Display of the limits for Vegetable Clearing. This Vegetable Clearing allows the saving of 15,2 cuts per 100 km.

9.5

Vegetable matters and their effect on the fabric appearance

9.5.1

Field test

In this field test, an investigation about the contamination and its impact on yarns has been done. In order to realize the effect of the contamination on the final product, the after treatment processes of the yarn were simulated. For this field test, 100% medium staple Greek cotton was used. The contamination from the blowroom over a lot of seasons was collected and classified into categories according to their frequency and appearance characteristics. Then the contaminated samples together with cotton yarn were prebleached and bleached. The material after the treatment was analyzed under a microscope and pictures were taken.

USTER® QUANTUM 3

9.9

9


The results of the survey had shown that more than 70% of the foreign material that had been found in the blow-room was decolorized with pre-bleaching including feathers, cotton plant residuals, colored cotton due to infection. The plastics or wool was not affected by bleaching. The vegetable residuals were not fully always decolorized but some of them remain of a yellowish shade after prebleaching. The majority of the colored contaminants were from the strings which have been used for cotton transportation and ginning and from fabrics (cloths).The non-affected material was inorganic material (Fig. 9-19 and Fig. 9-20).

Fig. 9-19

Effect of bleaching on foreign fibers. The inorganic foreign fibers hardly change the color.

Fig. 9-20

Effect of pre-bleaching on vegetable matter. Already after pre-bleaching most the vegetable fibers do not differ in color from normal cotton.

9.10

USTER® QUANTUM 3


9.5.2

9

Reasons and measures to minimize vegetable matter in yarns

In Table 9-1 and Table 9-2, the origin of the faults related to yarn contaminations is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. VEGETABLE MATTER CONTAMINATION Origin of Faults

Possible Reasons and Preventive Actions Prefer – when possible – to use cotton with low content of foreign fibers and vegetable matter.

Bale management

Controlled recycling of waste Blowroom

Optimize and control the settings and maintenance of the blowroom machines

Cards


Drawing frame


Combing


Table 9-1

®


Improvement

®

Quality control of foreign fibers and vegetable matter with USTER TESTER when dealing with new raw material

®

Proper setting of foreign fiber and vegetable matter detection


®

Separate outlier bobbins with too many foreign fibers with quality alarm settings ®


Long-term control of quality level

Preventive measures and tools for the management of foreign fibers and vegetable matter

USTER® QUANTUM 3

9.11

9

9.12


USTER® QUANTUM 3

Detection of polypropylene fibers with USTER® QUANTUM 3

10


10.1

Introduction

10

With the foreign fiber measuring method, only colored foreign fibers can be detected in a yarn. Foreign fibers consisting of polypropylene, however, are often white or without any color and are therefore, hardly detectable with the foreign fiber detection principle because there is no color difference to cotton. Therefore, a new measuring principle was developed to find these foreign fibers. Polypropylene fibers are mostly stiff, ribbon-like fibers which often protrude from the yarn body (refer to Fig. 10-1). Polypropylene is used as a package material for cotton bales and as such the source of the contamination of cotton.

Fig. 10-1

Examples of PP fibers taken with a scanning electron microscope / OE rotor yarn

As they are not found with the conventional foreign fiber detection, they are only detected after dyeing or finishing. Thus they first become visible in the finished woven or knitted fabric. A polypropylene fiber is shown in a raw fabric (Fig. 10-3) and after dyeing (Fig. 10-4). There are more and more complaints in the textile chain because of polypropylene fibers remaining in the fabric. The damages are enormous since many polypropylene fibers can only be detected in finishing.

USTER® QUANTUM 3

10.1

10


Fig. 10-2

Examples of polypropylene fibers / Optical microscope photography

Fig. 10-3

Polypropylene fiber in a knitted fabric before dyeing

10.2

USTER® QUANTUM 3


Fig. 10-4

10

Polypropylene fibers in a knitted fabric after dyeing

The fact that the PP fibers do not absorb dyestuff used for cotton will always lead to visible PP fibers in fabrics. The aim of the USTER polypropylene fiber detection development was not only to detect these white or translucent fibers, but also to be able to classify the length and the thickness reliably. A considerable part of cotton bales are embedded in polypropylene bags. If these bags are not handled carefully either after the ginning process, on transit or in the blow room of spinning mills, there is a high probability that polypropylene fibers contaminate the cotton. The USTER® QUANTUM 3 has a new, smart polypropylene (PP) clearing system. The clearer settings are very easy since the system proposes a smart limit which is a good starting point again at the touch of a button. This new smart clearing limit is different from the previous detection system. Further, the new USTER® QUANTUM 3 polypropylene clearing has no count, length or speed restrictions. The system is also less affected by environmental conditions. The PP option is available for all capacitive clearers (C15 and C20). With the help of the USTER® QUANTUM 3 smart polypropylene clearing, the can detect very fine and short polypropylene fibers.

10.1.1 Configuration of a PP-clearer For polypropylene clearing the measuring head C15 or C20 can be used, with foreign fiber sensor and additional polypropylene feature. A software upgrade for PP clearing is not possible, as it requires hardware changes in the Central Clearing Unit (CCU) only.

Fig. 10-5 ®

Configuration of a USTER QUANTUM 3 with PP clearing / Required options / Clearer iMH C15F30 or C20F30

USTER® QUANTUM 3

10.3

10


10.1.2 Frequency of PP fibers The PP fibers are much less common than colored foreign fibers. Trials have shown that the frequency of PP fibers is about 5 – 20% compared to colored foreign fibers as a rough estimate. In the table below, there are experience values of the ratio of polypropylene cuts to the cuts of thin and thick places and conventional foreign fibers. It can be seen that even with additional cuts caused by the PP clearing, the clearing efficiency only changes insignificantly. Reasons for splices

Splices / 100 km

Number of bobbin changes

34

Disturbing thin and thick places

30

Conventional foreign fibers

30


2

Total splices

96

Table 10-1 Number of splices per 100 km, count Nec 30, 100% cotton, combed

Fig. 10-6 below shows the frequency of PP fibers taking into the process (carded or combed) and the count of the yarn. It can be seen that the number of PP fibers decreases when a combing process is added and the yarn count becomes finer. In combing the stiff large PP fibers can be removed. The finer the count, the more short fibers are removed – thus more PP fibers can be eliminated as well. On the ring spinning machine, PP fibers often lead to yarn breaks on medium and fine yarn counts since the PP fiber weakens the yarn. Furthermore, finer yarn counts have a smaller number of fibers in the cross-section and, therefore, a PP fiber has a higher effect on the end break rate than on a coarse yarn. In a field trial carried out the number of detected PP fibers in carded yarns was by 38% higher compared to combed yarns (see Fig. 10-7 and Fig. 10-8). A PP fabric moving through the card shows up as a cluster of fine fibers in the card sliver. For a fine yarn the drawing ratio is much higher than for a coarse yarn. Therefore, the distance from PP fiber to PP fiber is higher and, therefore, the number of PP fibers in fine yarn is lower per unit length.

Fig. 10-6

10.4

Frequency of PP fibers in carded and combed cotton ring yarn (RSM = ring spinning machine)

USTER® QUANTUM 3


10

To illustrate Fig. 10-6 above, the following trials were carried out in a 100% cotton spinning mill. PP fibers were extracted from a carded yarn, Nec 14, and from a combed yarn, Nec 20. For both materials the winding machine was running at the same speed of 1300 m/min. The same PP settings were used. In Fig. 10-7 one can see some of the big and stiff polypropylene fibers, which were removed on the winding machine from a carded yarn, Nec 14. Altogether 3.4 PP fibers were detected per 100 km.

Fig. 10-7

100% cotton, Nec 14, carded

In Fig. 10-8 the polypropylene fibers, which were extracted from a combed yarn, Nec 20 can be seen. The PP clearer detected 2.1 PP fibers per 100 km.

Fig. 10-8

100% cotton, Nec 20, combed

USTER® QUANTUM 3

10.5

10


It can also be observed that the PP fibers from the combed yarn are much finer than the PP fibers taken out of the carded yarn. This is due to the additional combing process which eliminates many coarse PP fibers. In Fig. 10-9, one can see PP fibers taken out of a compact yarn Nec 30. They are even finer than the ones shown in Fig. 10-7 and Fig. 10-8.

Fig. 10-9

100% cotton, Nec 30, compact yarn with PP fibers

10.1.3 Application range of PP-clearing, ring-spun yarn Yarn types At the moment, PP clearing can be used for 100% combed and carded cotton yarns, compact yarns included. iMH Types - All capacitive clearers C15 F30 and C20 F30 / The PP efficiency of C15F30 is higher Count range – Same as the range for 100% cotton yarns for C15 and C20 Speed – No restriction Length – No hard limit Humidity range - No hard limit

Fig. 10-10

10.6

Count range of polypropylene detection

USTER® QUANTUM 3


10

In Fig. 10-11, the yarn count frequency of ring-spun yarns produced worldwide is shown. It can be noticed that the entire count range is covered with PP clearing.

Fig. 10-11

10.2

Range of yarn counts produced worldwide, ring spun yarn.

Scatter plot

The USTER® QUANTUM 3 interprets and displays the polypropylene characteristics with the help of a scatter plot. It is the graphic representation of the detected PP events within a classification matrix. Each event is marked with one dot. The vertical scale represents the visual appearance or intensity and the horizontal axis represents the vegetable fault length in cm. Fig. 10-12 shows a scatter plot with yarn faults as seen by the USTER® QUANTUM 3, with all the frequent events recorded (grey dots), the actual clearing limit and the area of the disturbing yarn faults (red dots).

Fig. 10-12

Frequent and seldom-occurring yarn faults. Measured yarn length: 2298 km

The scatter plot also depends on the raw material. If a yarn is produced from cotton having a lot of polypropylene fibers the scatter plot will be denser with many dots, and a high number of cuts has to be expected.

USTER® QUANTUM 3

10.7

10


Examples of various scatter plots

Fig. 10-13

Yarn Ne 40, 100% cotton, combed, knitting, 1438 km. Low amount of PP fibers: 1,7 PP fibers per 100 km

Fig. 10-14

Yarn Ne 60, 100% cotton, combed, weaving, 1952 km. High amount of PP fibers: 7,2 PP fibers per 100 km

Fig. 10-15

Yarn Ne 40, 100% cotton, combed, compact, 2298 km. Low amount of PP fibers: 3,2 PP fibers per 100 km

Fig. 10-16

Yarn Ne 60, 100% cotton, combed, compact, weaving, 2254 km. High amount of PP fibers: 6,6 PP fibers per 100 km

10.8

USTER® QUANTUM 3


10.3

10

Clearing limits for polypropylene fibers

10.3.1 Standard way of optimizing clearing limits: Manual clearing limits entry Fig. 10-17 shows the clearing limit as shown in the setting window of the Central Clearing Unit (CCU). The USTER® QUANTUM 3 gives us the chance of determining our clearing limits by placing a maximum of 8 set points PP1 to PP8. In Fig. 10-17, we can see 4 setting points (red rectangle) and the clearing limit for PP polypropylene. By this setting method the effects on the change of the parameters on the clearing limit can be demonstrated directly. As soon as we enter new values at set point, the next one will appear until we reach the 8th set point. This means after we enter the values for PP1, set point PP2 will appear and it will continue the same way.

Fig. 10-17


Set points have two parameters. These are: intensity (%) and reference length (cm).

Intensity The intensity (%) is a parameter for the clearing limits of the corresponding fault channel. The intensity setting shifts the clearing limit upwards (less sensitive) or downwards (more sensitive). PP1 = 30%, Fig. 10-17.

Reference length The reference length (cm) is a parameter for the clearing limits of the corresponding fault channel and shifts the clearing limit to the right (less sensitive) or to the left (more sensitive). PP1 = 0.4 cm, Fig. 10-17.

USTER® QUANTUM 3

10.9

10


10.3.2 Setting a smart clearing limit for polypropylene fibers Polypropylene defects are very disturbing, especially in dark dyed fabric. With the PP option the USTER® QUANTUM 3 can detect white or colored polypropylene fibers coming from bale packing material and other sources. Polypropylene fiber contaminations are well visible as white fault after dyeing of the finished cloth because the polypropylene fiber doesn’t absorb cotton dyestuff. The PP feature detects polypropylene in cotton yarn during winding. But it is not just restricted to appearance issues. Similar to regular foreign fibers, polypropylene defects can also cause breaks in weaving preparation or on looms. Polypropylene elimination capability is slowly becoming a crucial flexibility for spinning mills to meet higher quality needs. Thanks to technological improvements, the USTER® QUANTUM 3 has a high polypropylene detection rate and at the same time spends relatively less cuts to remove them. This has been proven with several field trials which have consistently shown a high removal efficiency of polypropylene including short and fine PP fibers with high cut efficiency. Similar to the yarn body, after running only a few kilometers of yarn, the first impression of the scatter plot and the events will appear. In order to see the scatter plot, the should press the scatter plot key (Fig. 10-18). Besides the scatter plot, the cut faults and remaining events and the number of expected fault cuts per 100 km can be seen on the screen. The used setting limits will appear directly on the same setting page (Fig. 10-18).

Pressing key presents • Scatter plot of the cut faults and remaining events. • Number of expected fault cuts / 100 km. Clearing limit Red dots = cut yarn faults. Grey dots = remaining events. = Proposes the starting point for the clearing limits based on the body.

Fig. 10-18


As soon as the button at the smart limit window is pressed, the yarn body and the expected cut figure per 100 km is displayed on the same setting page (Fig. 10-18). The sensitivity of the smart limit can be changed stepwise by pres and down keys, whereupon the limit moves away from or approaches the area of frequent events. At the same time, the new calculated setting point values appear in blue color. Every time this key is pressed, the limit moves further away or approaches the scatter plot, and the adapted setting limits are presented in blue color. Simultaneously, the expected cut figure is calculated based on the real yarn events.

10.10

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10


The new setting point proposals = Smart Limit 1 step less sensitive. = Smart Limit 1 step more sensitive. = Show scatter plot = confirm and activate optimized clearing limit. = cancel all modifications

Fig. 10-19


PP yarn faults are displayed together with all the other yarn faults of the machine, a group or a winding position. It can be switched from absolute values to values per 100 km.

Fig. 10-20

PP yarn fault registration

USTER® QUANTUM 3

10.11

10 10.4


Polypropylene fibers and their effect on the fabric appearance

Polypropylene fibers can hardly be recognized in grey fabrics, because they cannot be distinguished from the point of view of color. However, they can easily be recognized after dyeing because polypropylene fibers do not absorb textile dyestuff. Polypropylene fibers cannot be recognized with sensors which need a difference in colour for a distinction. Therefore, a particular sensor technology is used to eliminate polypropylene fibers. Fig. 10-21 and Fig. 10-22 show a white polypropylene fiber knitted into a turtleneck sweater. A considerable proportion of cotton bales are packed in white polypropylene bags. If these bags are not handled carefully, either after the ginning process, during transportation or in the blowroom of the spinning mill, there is a high probability that polypropylene fibers will contaminate the cotton. Such fibers are spun into yarns. White polypropylene fibers can hardly be recognized in grey fabrics, because they cannot be distinguished from the point of view of color. However, they can easily be recognized after dyeing because polypropylene fibers do not absorb dyestuff (Fig. 10-21 and Fig. 10-22).

Fig. 10-21

10.12

White polypropylene fiber, turtleneck, knitted / 100% cotton, combed, Nec 34 (17,5 tex)

Fig. 10-22

Magnified PP fiber in turtleneck

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10


10.4.1 Reasons and measures to minimize foreign fibers in yarns In Table 10-2 and Table 10-3, the origin of the faults related to yarn contaminations is given. Possible reasons and preventive measures to avoid such faults are explained and various USTER® tools for improvement are presented. CONTAMINATION Origin of Faults


Bale management

Prefer – when possible – to use cotton with low content of foreign fibers. Sometimes spinning mills tend to create or intensify the contamination problem. A popular mistake is the use of plastic bags for the waste collection and transportation inside the spinning mill. Particularly the use of polypropylene bags should be avoided.

Blowroom

Controlled recycling of waste

Cards


Drawing frame


Combing


Table 10-2

®


Improvement ®


®

Quality control of foreign fibers with USTER TESTER when dealing with new raw material Proper setting of foreign fiber detection

®

USTER QUANTUM CLEARER ®


Separate outlier bobbins with too many foreign fibers with quality alarm settings Long-term control of quality level

Table 10-3 Preventive measures and tools for the management of foreign fibers

USTER® QUANTUM 3

10.13

10

10.14


USTER® QUANTUM 3

Various settings and applications of USTER®QUANTUM 3

11


11

Up to now, various smart features of the USTER® QUANTUM 3 have been explained with the help of different examples. At the beginning of this chapter, we would like to show the some other smart and helpful applications which can be used in various comparisons and data evaluations. The last part of the chapter is focused on monitoring winding functions of the winding machine.

11.1

Comparison of different clearing limits and article settings

11.1.1 Comparison of various clearing limits The USTER® QUANTUM 3 gives the chance of comparing up to three different clearing limits on the same yarn body. These three limits are presented in Fig. 11-1, with different colours: Red = Active clearing limit for a yarn which is currently on the winder (Fig. 11-1) C1, Dark blue = Clearing limit for a yarn which has a yarn count of Ne 34, Article name is Geneva (Curve 1 in Fig. 11-1) C2, Light blue = Clearing limit for a yarn which has a yarn count of Ne 40, Article name is Sydney (Curve 2 in Fig. 11-1). As it can be seen in the example Fig. 11-1, the can compare 2 various clearing limits with different names to his current clearing limit. Selection of clearing channel

Selection of article

Article

Active clearing limit = red Curve 1 = dark blue Curve 2 = light blue

Display of the clearing limit from 2 other articles

Fig. 11-1

Comparison of various clearing limits

But there are also other usages. For example in Fig. 11-2, the comparison of two different settings of the same article is given. Before editing the current article setting (Changed-Training/Test/30.0 NeC), the should make a copy of the article and give a different name. In this example, the new given name is “Training/Test/30.0 NeC” and can be seen in C1 area. After the modifications of the current article ' “Changed-Training/Test/30.0 NeC”, the can detect the differences to the original settings (dark blue line, C1) very easily: With the help of this comparison the will not use any production data and be switched to the original settings.

USTER® QUANTUM 3

11.1

11


Fig. 11-2

Comparison of current modified article settings to the original article settings

Another application is the comparison of the current article to the chosen smart limit. In Fig. 11-3, the original article settings are given as Curve 1 with dark blue color.

Fig. 11-3

11.2

Comparison of the chosen smart limit to original article clearing limit

USTER® QUANTUM 3


11

11.1.2 Recreate or recall of the factory settings of the default articles Up to version release 1.01.05, it is possible to recall the factory settings of the two default articles (capacitive and optical default). To recreate the default article again, the can select and copy any article by pressing 'Copy article' button. After that “create a new article” option should be chosen (Fig. 11-4, left) and confirmed. However it is also possible to reset an existing article to the factory default settings. For this, the should choose the article that should be reset in the 'Copy to' selection box instead of creating a new article (Fig. 11-4, right).

Fig. 11-4

11.2

Recalling the factory settings of the default articles (capacitive (left)and optical (right))

Display of Data and Alarms

11.2.1 Display of Data and Alarms with the help of bar graphs With the USTER® QUANTUM 3, it is possible to display the events occurring in the various evaluation channels by using data bar graphs. These are used for monitoring quality and finding the outliers and as aid for setting the clearing limits. There are various categories and related features and can be found under the “Display” main menu, in the machine summary page. These categories and features are given in Fig. 11-5.

USTER® QUANTUM 3

11.3

11


Fig. 11-5

Machine summary categories and their features. Abbreviations: see Appendix, chapter 16.2.

Fig. 11-6

Machine summary submenu in the “Display” main menu

11.4

USTER® QUANTUM 3

11


In Fig. 11-7, an example of these bar graphs is given. Here the category is “Yarn Faults YF” and feature is YF (see Fig. 11-5). As it can be seen on Fig. 11-7, every group has its own mean value which is highlighted with a black horizontal line. The values can be displayed according to current data or last shift. The can also select relative or absolute display values. By using these bar graphs it is very easy to compare various winding positions and find the outliers. However, because the scale is changing automatically, the should also check both the actual value for a winding position and the mean value of the group before making decisions. Red vertical line = selected winding position (here SP 6) SP = winding position (spindle) (Totally 50 winding positions are in production) Black horizontal line = average value of group (Mean value for group 1 = 146.06 /100 km) Gr.no. = group in production (totally 3 groups are in production)

Fig. 11-7

Group settings of the winding machine

11.2.2 Display of Data and Alarms with the help of exception reports Another interesting and useful application is exception report. The can define exception thresholds for the following event groups: •

Yarn fault total YF

•

Yarn alarms YA

•

Quality alarms QA

•

Foreign fiber F

•

Foreign fiber alarms FA

•

Faulty splices J

For the above mentioned event groups, the tolerances should be entered as +/- deviation in % of group average value and/or events per 100 km or absolute number of events as upper tolerance limit. In order to print out the values of all winding positions, “Print all SP” should be selected, otherwise only the values of the exception winding positions will be printed out. The lines in the report with all values = 0 will not be printed.

USTER® QUANTUM 3

11.5

11


Fig. 11-8

Definition of exception report in the “Reports” main menu

11.2.3 Display of yarn faults with the help of textile alarms With the USTER® QUANTUM 3, it is possible to define and display textile alarm limits in the settings main menu. A textile alarm is triggered when the set number of yarn faults per reference length is reached. The winding position will be blocked and the iMH LED lights up continuously. The setting parameters are number of faults and the reference length in km.

Fig. 11-9

Definition of yarn fault alarms in the “Settings” main menu

In the “textile alarms” submenu of the “Display” main menu, it is possible to display all yarn faults of the machine, a group or a winding position over the selected period. The values for the machine, for a group or for a winding position can be selected. Also various periods like current, current / last shift or current / last article can be chosen and displayed. The "current" counter is reset with •

Shift change

•

Article change

•

Clear counters of a group

11.6

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Fig. 11-10

11

Textile alarms submenu in the “Display” main menu

All textile and technical alarms which have occurred during operation are displayed in the “Alarms” function menu.

In the textile alarms window (Fig. 11-11, left), consecutive winding positions with the same alarm are shown as a group. Textile alarms can be deleted either on the control unit or on the measuring head. In the technical alarms and warnings window (Fig. 11-11, right), each individual alarm is displayed with date and time and ed in the Service Logbook. Textile alarms and warnings can be deleted on the control unit.

Fig. 11-11

Textile alarms (left) and technical alarms and warnings (right)

Explanation of textile alarm types: Textile Alarm

Quality Alarm

Explanation of technical alarm and warning types: Warning

USTER® QUANTUM 3

Technical Alarm

11.7

11


11.3

Collecting defects

11.3.1 Introduction To better understand defects Uster Technologies always recommends to put the fault on a black board (disturbing thick and thin places) and on a white board (foreign fibers). To make this easier the iMH-LED function can stop the winding position at a particular yarn defect type and the fault length, percentage and classification can be displayed on the event report of the Central Clearing Unit.

11.3.2 Event display by the red light at the sensor (iMH-LED) The two LEDs at the iMH are used for the display of textile and technical alarms. Furthermore, it is possible to show the status of the clearer installation, especially during a lot change or during start-up of the installation. In addition, the LED can be used for the display of cut events. This can be very helpful, when certain yarn faults should be removed for visual examination. After the setting of the corresponding function code at the Central Clearing Unit, the iMH-LED displays the code as soon as the desired cut type is triggered. The LED can be deleted by pressing the iMH-button or it switches off automatically when the winding position is started again. On new winding machines, the winding position automatically switches to "test mode". This means, that the winding position will be stopped until it will be turned on again manually. This is valid for the following machine types: •

Schlafhorst AC-338

•

Schlafhorst AC-5 and ACX5

•

Murata PC-21

•

Savio Espero

•

Savio Orion

•

Savio Polar

•

Smaro

The iMH LED display function can be assigned to the whole machine, one group or a range of winding positions. When the programmed cut occurs: •

the iMH cuts

•

iMH LED flashes according to the selection

•

red winding position lamp lights up continuously.

The should enter the range and cut type for the 3 display variants. These are:

11.8

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Fig. 11-12

11

iMH LED Display Function

Explanation: The iMH-LED is turned on, when a N, FD or PP-cut is triggered. In the event report (Fig. 11-12, right), the yarn faults / cuts are also displayed showing the size / intensity in % and length in mm, as well as their classification. The events which should be displayed have to be selected in the Configuration Menu (Valid up to Release 1.01.05, for higher release numbers this will not be necessary anymore, Fig. 11-13, left). The selected events are displayed with date, time and winding position information (Fig. 11-13, right).

Fig. 11-13

Configuration menu (left) and Event Reports menu (right)

11.3.3 Yarn fault cards Yarn fault cards are an easy and very helpful instrument for the collection of yarn faults and their evaluation. The displayed yarn faults provide a very good impression about the existing faults. By means of the visualization the can decide which faults can remain in the yarn and which faults have to be cut. This depends also on the final product.

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11.9

11


Yarn fault cards have a white and a black side. For greige yarns the black side is used in order to document yarn faults like thick and thin places. The other side, i.e. the white side of the yarn fault card, is used for the documentation of foreign fibers and vegetable matter in the yarn. White polypropylene fibers should also be put on the black side. By this method, the yarn body disappears in the background and the foreign fibers and vegetables can easily be recognized. On top of the yarn fault card there is room for yarn, test and clearer identification. The information about the clearing limits are of special importance in order to be able to compare the results of future tests. Depending on the application, the following decisions can be made with the aid of yarn fault cards or they can serve to obtain more information: •

clearing limits can be better determined and optimized

•

with every modification of the clearing limits the expected cuts can be determined in advance

•

the quality of the current production can be controlled in accordance with textile aspects, i.e. with respect to the form of the yarn fault

To sum up, it can be said that yarn fault cards with documented faults together with the classification and the scatter plot serve as a basis to decide which clearer settings have to be chosen.

Yarn: Ne 30, 100% cotton, combed, bobbins Sensor: iMH C15F30 S-faults

Fig. 11-14

Yarn: Ne 30, 100% cotton, combed, bobbins Sensor: iMH C15F30 FD-faults

®

USTER yarn boards, thick places (left), foreign fibers (right)

When collecting thick places (e.g. N and S defects) it is quite easy to see the defects in the yarn. For collecting the foreign fibers it is needed to use the white side of the board and make sure that there is enough light so that the defect can be seen in the yarn easily. Sometimes it appears that the defect, especially at low reflections e.g. 5 or 7% can hardly be seen under insufficient light conditions or even need the aid of a magnifying glass to see it. Therefore the yarn board always should be used as as shown in the examples, and, whenever possible, a magnifying glass. When the has the advanced classification option, then tailored classes can also be used to inspect yarn fault within a length and amplitude range.

11.10

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11.4

11

Monitoring of winding functions

On most modern winding machines, the monitoring of the yarn t process is carried out by the yarn clearer. The functions of the clearer include the monitoring of the: •

Upper yarn (U)

•

Drum sensor (DSM)

•

Splice (t, J)

•

Drum wrap (DWM)

•

Yarn jump (JPM)

•

Cut (CTM)

•

Zero point (ZPM)

The display of the group settings can change according to the winding machine type. The following additional parameters can be seen on the display: • Speed: manual winders only • Startup time: manual winders only • Don’t cut drum wrap (Orion (Polar only), Espero, Smaro, Spero • DSM Drum Signal monitoring (most machines)

• Don’t cut drum wrap (Orion (Polar only), Espero, Smaro, Spero

Fig. 11-15

Group settings of the winding machine

Speed Setting of the winding speed (for manual winding machines only). Setting: Speed per group in m/min

Length correction Correction factor to get correspondence between displayed and actual wound yarn length. Setting: The correction factor can be set for each group between 0.800 and 1.200 (+/- 20%). The correction factor has no influence on the set reference lengths of the clearing channels.

Startup time The start-up time must be set to measure the fault length correctly on a manual winder during the start up acceleration. The start-up time represents the time between the winding position start until it has reached the nominal speed. Setting: 0.6, 1.2, 1.8, 2.4 and 3.0 s

USTER® QUANTUM 3

11.11

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JRA Splice failure rate alarm The splice failure rate in % is a relation between total splices and splice cuts (Jp + Jm). A textile alarm occurs and the LED of the sensor lights up if the relation exceeds the set JRA alarm limit. Setting: Alarm limit 0.0% to 100.0% Alarm limit: 0.0 = monitoring inactive

Special monitoring functions Special monitoring can only be switched on and off using «Customer Service» access rights. If the special monitoring functions are activated they react as follows:

ZPM Zero point monitoring (ZPM): If, during the splicing cycle, there is still yarn or fluff in the measuring zone despite the blow-out, then a ZPM event is counted but no zero adjustment made. Clean measuring zone.

CTM Cut monitoring (CTM): If the iMH repeatedly detects running yarn after a cut then a technical alarm is triggered. Check cutting device.

JPM Yarn jump monitoring (JPM): A cut is triggered if the yarn jumps out of the measuring zone for a moment e.g. because of a large yarn fault.

JPA Yarn jump alarm (JPA): A cut and an alarm is triggered if the yarn jumps out of the measuring zone 3 time per 1 km. The winding position is blocked and a textile alarm is displayed. Possible settings for JPM and JPA: Effect at yarn jump

JPM

JPA

–

–

Yarn jumps are ed and counted.

X

–

A cut follows a yarn jump.

X

X

Cut, textile alarm with SP blocking (3 x JMP / 1 km).

Table 11-1

DSM Drum signal monitoring (DSM): A technical alarm is activated if the iMH does not receive a guide drum signal after the winding position starts up. Check guide drum sensor.

DWM Drum wrap monitoring (DWM): DWM prevents the yarn from getting wrapped around the drum with a cut.

11.12

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11

DWA Drum wrap alarm (DWA): DWA prevents the yarn from getting wrapped around the guide drum with a cut. At the same time a textile alarm is activated which blocks the winding position. “Don’t cut drum wrap” prevents loose pieces of yarn on ESPERO, ORION, POLAR, SMARO and SPERO winder. DWM

DWA

Don’t cut DW

–

–

–

Drum wraps are ed and counted.

X

–

–

Cut at drum wrap

X

Espero, Orion, Polar, Smaro and Spero: Winding machine stops without cut.

X

–

Effect at danger of drum wrap

Other machines: not available. X

X

–

Cut, textile alarm with SP blocking

Table 11-2

Fig. 11-16

Display of the group setting of the winding machine

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11.13

11


11.4.1 Monitoring of the yarn t process with the USTER® QUANTUM 3 The monitoring of the yarn t process by the clearer is carried out according to the splicing process of the winding position (Please see Chapter 5). The individual steps are:

Monitoring of the upper thread (U) If double or even multiple yarns are coming from the cone, the cutter has to be triggered. → U-channel with setting of U%

U-channel for upper threads (U) The monitoring of the upper thread is only possible on machines on which the upper thread runs through the clearer measuring field before splicing. The U-channel prevents that an upper thread (yarn end removed from the cone) is ed as a double thread or as a loop with the yarn which is drawn off from the bobbin. Therefore, the upper thread is checked when putting it into the measuring field. With a correct setting of the U-channel, any upper thread which is drawn in as a double or multiple thread, will be cut.

11.4.2 Monitoring of the settings All the settings should be adjusted according to the produced yarn, especially after putting into operation of the machine. This coordination helps to avoid surprises afterwards.

Monitoring of the settings for the upper yarn detection With the chosen setting U, a double yarn removed from the cone must always be cut. This can be checked with a prepared cone with double yarn or with suctioning off an additional yarn from a bobbin. The setting is correct, when all double yarns are cut. Single yarns should not be cut. Incorrect detection of single yarns as double threads should not be higher than 1 to 2%.

Monitoring of the yarn t setting With the chosen setting Jp and the corresponding length a good quality t should not be cut. The checking is done best with a double yarn from the cone side. During this procedure, the U-channel has to be switched off (U = 0%). Therefore, Jp has to be set rather sensitive. It has to be pointed out that the set length does not have to correspond with the actual yarn t.

11.4.3 Splice classification Up until now, visual checks of the splice were carried out in periodic intervals with random samples. This is also recommended by the machine manufacturers. However, this check is very timeconsuming.

11.14

USTER® QUANTUM 3


11

In order to make this procedure of the splice control easier, the USTER® QUANTUM 3 splice classification was introduced. During the measurement, the values are recorded and displayed as a scatter plot in the classification matrix (Fig. 11-17). The classifications of each single winding position can be looked at separately, in order to be able to find the winding positions at which the splice formation does not meet the quality requirements.

Fig. 11-17

Scatter plot with splice classification

11.4.4 Yarn jump monitoring (JPM, JPA) JPM A hard yarn fault, like for example attached fiber balls or a yarn loop, can cause a significant increase of the yarn tension at a deflection point. The subsequent slackening of the yarn can cause the yarn to jump out of the clearer measuring field. With other words: a hard yarn fault can jump out of the measuring field and thus will not be monitored. With the yarn jump monitoring function a cut is triggered as soon as the yarn is out of the measuring field and a 100% monitoring cannot be guaranteed anymore. JPM-cuts are mainly caused by yarn faults. In principle, JPM-cuts should, therefore, be considered as yarn fault cuts. JPM-cuts can also be caused by a very unstable yarn movement. Our recommendation: Turn on function „Yarn jump monitoring“.

USTER® QUANTUM 3

11.15

11


JPA If the function JPA is turned on, a textile alarm is triggered for every JPM-cut which blocks the respective winding position

11.4.5 Drum signal monitoring (DSM) Winding machines with a guide drum signal generate a certain number of pulses per revolution of the drum. These pulses are used to calculate the yarn speed and the length of yarn faults. Without a guide drum signal, yarn clearing is not possible on those winding machines. If no guide drum signal is provided within approx. 5 seconds after the start of the winding position or if the clearer detects a failure of the guide drum signal, a DSM-cut and an alarm is triggered by the clearer. This means, that the clearer gets no yarn speed information. If the DSM monitoring is turned off, the drum signal will not be monitored and the yarn clearing might not be guaranteed. Our recommendation: Turn on function “Drum signal monitoring DSM“.

11.4.6 Drum wrap monitoring (DWM, DWA) DWM A drum wrap can occur, when the yarn breaks in the guide drum during traversing. After the break, the yarn usually stops briefly in the guide drum as well as in the measuring field. A drum wrap occurs when the yarn is subsequently wound onto the guide drum. The dynamic yarn detector (DYD) detects the brief stoppage of the yarn. The DYD is switched-off, which results in a DWM-cut and prevents a drum wrap. Practical experience has shown that this is mostly the case. But drum wraps can also happen for other reasons (sticking of the splice to the drum) and therefore, not all drum wraps can be avoided with this monitoring function. If the DWM monitoring is turned off, drum wraps cannot be avoided by the clearer. Some machine manufacturers also offer their own drum wrap monitoring. Our recommendation: Turn on function “Drum wrap monitoring DWM”.

Don't cut drum wrap If the function “Don't cut drum wrap” is activated (Espero, Orion, Polar, Smaro, Spero), the winding position will only be stopped, but no cut is triggered. This can avoid free flying yarn pieces. Our recommendation: Turn on function “Don't cut drum wrap”.

11.16

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11

DWA The drum wrap alarm prevents the yarn wraps around the drum by a cut. At the same time, a textile alarm is triggered which will block the winding position. Our recommendation: Turn off function “Drum wrap alarm DWA”.

11.4.7 Cut monitoring CTM With CTM monitoring, it is checked, if the yarn has been separated after a cut. If the cut fails repeatedly, a CTM alarm is triggered. If the CTM monitoring is turned off, the clearer cuts are not monitored. Our recommendation: Turn on the function “Cut monitoring”.

11.4.8 Zero point monitoring ZPM During splicing of a winding position, the clearer adjusts itself when the measuring field is empty. Deviations from zero are adjusted to zero again. The measuring field must be empty for this procedure. If this adjustment is carried out while the measuring field is not empty, the zero point would not be set correctly and wrong measurements could occur. With the zero point monitoring ZPM turned on, the condition of the measuring field is monitored during the zero point adjustment. In this case, the zero point adjustment is only carried out with an empty measuring field. If the ZPM is turned off, a zero point adjustment is carried out, even if the measuring field is not empty and also in case of a piece of yarn remaining in the measuring field. If the piece of yarn falls out of the measuring field during the adjustment cycle, the yarn clearer does not recognize the laid-in upper yarn. This can have the effect, that: •

a double yarn cannot be recognized as such and thus, will be wound on the cone

•

a normal yarn cannot be recognized with the consequence, that a new cycle is started, although no yarn is laid into the measuring zone.

Our recommendation: Turn on the function “Zero point monitoring ZPM“.

USTER® QUANTUM 3

11.17

11

11.18


USTER® QUANTUM 3

Clearing of slub yarns

12.

Clearing of special yarns

12.1

Introduction to fancy yarns

12

Fancy yarns are used in the textile industry for various applications. Therefore, fancy yarn manufacturing is not a niche market anymore. Up until now, it was not possible to determine the quality characteristics of fancy yarns in detail which are needed for a quality management. This can be done in the laboratory with the USTER® TESTER 5. An accurate determination of slub yarn characteristics is also required for negotiations and specifications between fancy yarn spinners and weavers, knitters, traders and retailers.

12.2

Clearing of fancy yarns

Slubs, neps, thick and thin places are noted as yarn faults and are considered as degrading features of yarn quality. During various processes, efforts are taken to minimize their occurrence. However, in fancy yarn production these features are introduced in the yarn in order to give visually attractive differences to the other fabrics [1]. Fancy Yarn is a yarn that differs from the normal construction of single and ply yarns by way of deliberately produced irregularities from the normal construction. These irregularities relate to an increased input of one or more of its components, or to the inclusion of random effects, such as knops, loops, curls, slubs, or the like. [6] There are various names which are used to describe the different yarn effects. Table 12-1 shows eight basic profiles of fancy yarns. These yarn effects can be made by plying a number of yarns together or, with modified spinning techniques, most can be spun from sliver or roving [1]. Basic yarn profile

Designations

Spiral

Mock spiral, mouline, jaspe

Gimp

Frise, caterpillar, onde

Slub

Ground slub, injected slub, injected flame (also called tear- off flame)

Knop

Knot, nep, noppe, button, reverse caterpillar, flake

Loop

Boucle, frotte, pong, mock-spun chenille

Cover

Twisted flame

Chenille

Woven chenille, plied chenille

Snarl Table 12-1 Various fancy yarns [1]

USTER® QUANTUM 3

12.1

12


Fig. 12-1

Examples of effect twist fancy yarns [1]

There are also several classifications for fancy yarns. Table 12-1 gives one of these classifications according to the employed production methods. Here mainly two production methods are employed: Produced effects are based on twisting or doubling of yarns together to create the fancy yarn effect from already spun yarns. Spun-effect yarns are fancy yarns spun directly from fibers fed to the spinning system [1].

12.2

USTER® QUANTUM 3


Yarn (produced) effects

12

Spun yarn effects

Regular effects

Controlled discontinuous effect

Regular effects

Controlled discontinuous effect

Spiral

Reverse caterpillar

Spiral

Button

Mouline

Neps

Mouline

Slub

Loop

Knots

Loop

Caterpillar

Boucle

Knop

Boucle

Combinations

Gimp

Slub

Gimp

Onde

Onde

Snarl

Chenille

Cover Chenille Table 12-2 Classification of fancy yarns [1]

If fancy yarns have to be cleared on winding machines, the following recommendations have to be taken into consideration: All the fancy yarns have a regular pattern (pseudo-random formation). If faults occur, the regular pattern is disturbed and can be recognized in the scatter plot (Yarn Body Clearing). Such faults can be eliminated accordingly. In this chapter we will concentrate mainly on slub yarns.

12.3


A slub yarn is a yarn in which slubs may be created to produce a desired effect. Generally, slub yarns are divided into two classes: (i) spun slubs, and (ii) plucked (or inserted) slubs. Spun slubs may be produced by an intermittent acceleration of one pair of rollers during spinning or by the blending of fibers of different dimensions. Plucked slub yarns are composed of two foundation threads and short lengths of straight-fiber materials that have been plucked from a twistless roving by roller action [6].

As the range of applications is very wide for slub yarns, there are also different types of slub yarns. They are usually called slub yarns, multicount yarns and multitwist yarns.

USTER® QUANTUM 3

12.3

12


Table 12-3 below explains the differences between these three yarn types. Term

Twist

αe

Mass

Slub length

Slub yarn

constant

variable

variable

Any length up to 2 meters

Multicount

variable

constant

variable

Any length over 2 meters

Multitwist

variable

variable

constant

any

Table 12-3 Definition of different slub yarn types

It is also possible to distinguish between structured slub yarns and slub yarns with distinctive slubs. Structured yarns can be characterized as very uneven yarns without any clear slubs. Fig. 12-2 shows an example of a distinctive slub yarn on a blackboard.

Fig. 12-2

Slub yarn with short slubs on a blackboard

Setting of a clearing limits for slub yarns With the USTER® QUANTUM 3, there is a special setting for slub yarns. For this, we can use the radio buttons to switch from NSL thick places to Slub Yarn settings window. The aim of this feature is to define the clearing limit to prevent the clearing of desired thick places in slub yarn. The events in the defined slub area should not be cut because this is a characteristic of the yarn. In order to clear slubs, instead of standard setting points P, we have the special setting points K1 to K3 to zone out areas where slubs should not be cut. For example: Set point K1 = 700% / from 10.0 cm to 25.0 cm. This means the slubs between 10.0 and 25.0 cm are not cut.

12.4

USTER® QUANTUM 3


12

It is possible to assign up to 3 K areas where slubs should not be cut Fig. 12-3.

Fig. 12-3

Slub yarn setting. No clearer cuts up to +700% from 10 to 25 cm.

Characteristic yarn faults in slub yarns The clearing of slub yarns should achieve the following: Specifically generated "thick places" should remain in the yarn, disturbing yarn faults have to be cleared. Slub yarns consist of at least 2 single yarns, i.e. if one of them is missing, the yarn clearer has to detect this. The existence of each single yarn has to be monitored. Faults in the single yarns have to be eliminated, in order to avoid any unevenness in woven or knitted fabric.

12.4

Clearing of yarns with nep or loop effects

Fundamentally, it can be said: •

The desired effect has to be monitored. If the effect is missing, a cut has to follow.

•

Each single yarn of the ply yarn has to be monitored.

•

Possible yarn faults in the single yarn must be monitored.

Fig. 12-4

Yarn fault in a bouclé yarn

USTER® QUANTUM 3

12.5

12


In summary, it can be said, that all irregularities of the visual impression of the end product have to be monitored.

12.5

Melange yarns

Melange yarns are produced by blending a certain percentage of fibers of different colors. Blending can be done in a very early stage of the process. This means, for example, mixing of multi-colored fibers in the opening line, feeding of slivers of different colors at the drawframe or directly at the spinning machine.

Characteristic yarn faults in melange yarns For melange yarns it is of particular importance that the blending effect, i.e. the blend of multicolored fibers is as regular as possible. If too many fibers of one component are missing, it is possible that stripes of a particular color occur in the end product.

Fig. 12-5

Melange yarn / Blending problems / Blend of black and white fibers 100% cotton, Ne 30 (20 tex), OE rotor

Fig. 12-6

Melange yarn / Blending problems

Choice of the measuring head It is not possible to monitor uneven color effects with a capacitive measuring head. The increase or decrease of one fiber component is less than the normal mass unevenness of a yarn. With the USTER® QUANTUM 3 iMH-O30, it is possible to monitor the proportion of blending. For the clearing of long color deviations, it is necessary to set the CC-channel accordingly. The defined length must correlate with the expected fault length. If necessary, the set length must be shortened and the diameter must be increased in 2%-steps.

12.6

USTER® QUANTUM 3


12.6

12

Core yarn

Core yarns are usually made of a filament core and a cover yarn made out of staple fibers. The main problem with core yarns (with respect to yarn clearing) is the detection of the missing core. When a core is missing, it causes a marginal change in diameter however it causes a higher change in mass. The capacitive clearer has, therefore, an advantage for this application. The change in mass is proportional to the fineness of the core. The USTER® QUANTUM 3 has a new capacitive sensor technology which has an even better signal ratio and therefore a higher possibility to detect the missing core. The detection is mainly possible when the change in mass due to the missing core is higher than 5-6%.

Clearing of core yarns (CY) Core yarn monitoring; detects the break of the core while yarn is running. A cut takes place if the cover thread is missing and at yarn break. The setting parameters are: Tolerated decrease in %. This setting is only active when the yarn type is core yarn. Sensitivity: 0% = Clearing channel inactive

Fig. 12-7

Core yarn setting (CY)

A missing core can only be detected if the mass of the core is at least 13% of the entire yarn mass.

Clearing of a yarn with missing cover Besides normal thick places, a missing cover is also disturbing. Therefore, a partly or completely missing cover must be monitored. In case of sewing threads, a classification of short neps is required. Neps are considered as disturbing events if they are occurring in high numbers. The frequency of such neps is an indicator for the running behavior of the yarn on the sewing machine.

USTER® QUANTUM 3

12.7

12

12.8


USTER® QUANTUM 3

The first hour at the new clearer system

13


13.1

Introduction

13

The USTER® QUANTUM 3 is the successor of the USTER® QUANTUM 2. With this new generation of yarn clearers, the has various smart tools in finding the optimum solutions in yarn clearing. The new USTER® QUANTUM 3 is focused on simplifying the complexities of yarn clearing and thereby enables the to easily and fully exploit all clearer capabilities and to optimize production costs every day. The USTER® QUANTUM 3 interprets and displays the yarn characteristics in minutes and proposes a starting position for clearing limits with a cut forecast by pressing a single button. We have prepared this chapter as a quick reference for the setting of the most important features of the USTER® QUANTUM 3. This chapter is targeted on the one hand at new and inexperienced s and, on the other hand, it is also relevant to everyone who is already experienced in yarn clearing and would like to learn the new features of USTER® QUANTUM 3. We believe that with the combination of Uster Technologies’ know-how with smart, reliable and modern technology, the will be able to deliver significantly better yarn quality and post spinning performance while most likely maintaining productivity.

13.2

Short description of the settings

This chapter is a quick reference for the setting of the most important features of the USTER® QUANTUM 3. One page is dedicated for each feature (pages 13.4 to 13.16). The setting procedures are shown graphically.

Create and start an article Whenever the article on the winding machine has to be changed, the designation of the article has to be made first. Page 13.3 shows what kind of steps have to be taken for a new article.

Setting a smart clearing limit for disturbing thick places (NSL) and thin places (T) Page 13.4 shows the selection of the optimum clearing curve for thick and thin places. For a few seconds or minutes the yarn runs with the default clearing curve. After this period the operator can see the yarn body on the screen. Now the clearing curve can be optimized either by moving the clearing curve up or down. The setting can be fixed by pressing the “confirm” button.

Setting of Periodic Faults (PF) Page 13.5 shows the settings for periodic faults.

Setting a smart clearing limit for dark foreign matter (FD) Page 13.6 shows the setting of the optimum clearing curve for the elimination of foreign matter.

USTER® QUANTUM 3

13.1

13


Setting a clearing limit for foreign mater (FD) with Vegetable Clearing (VEG) Page 13.7 shows the setting of the clearing curve for the Vegetable Clearing curve. With the setting of the Vegetable Clearing curve there are opportunities to the lower number of cuts per unit length, because most of the vegetables cannot be seen after bleaching.

Setting a smart clearing limit for Polypropylene Clearing (PP) Page 13.8 shows the setting of the clearing curve for polypropylene clearing. Polypropylene detection is significantly more difficult than the detection of colored fibers in white yarns because the color of polypropylene hardly differs from the color of yarn.

Setting a clearing limit for count deviation clearing (C) Page 13.9 shows the clearing of count variations in the length category 2 to 12 m. The count variations particularly serve for the recognition of wrong bobbins.

Setting a smart clearing limit for count monitoring clearing (CC) Page 13.10 shows the steps to be taken to monitor the count deviation of the yarn during the entire operation. The settings are also made between 2 and 12 m.

Setting a clearing limit for Splice Clearing (Jm /Jp) Page 13.11 demonstrates how the clearing limits can be set for splices. If bad or faulty splice is located above the splice clearing limit, the splice is eliminated and replaced by a better splice.

Setting of Q Parameters: Yarn Evenness (CV) The evenness CVm belongs to the most important quality characteristics of yarns. The reference length is selectable. Alarm limits are available for every single measurement as well as for the group average / mean value. The procedure is shown on page 13.12.

Setting of Q Parameters: Hairiness (H) Page 13.13 shows the settings for hairiness. The reference length is selectable. Alarm limits are available for every single measurement as well as for the group average / mean value.

Setting of Q Parameters: Imperfections (IP) Page 13.14 demonstrates the steps to be taken to set the sensitivity and the alarm limits for frequent thick places, thin places and neps. Outlier bobbins can also be detected and eliminated.

Setting of Q Parameters: Class Alarm Page 13.15 explains the settings for class alarm. It is an option to set alarm limits for up to 5 individual class of the Classimat matrix.

Setting of Q Parameters: Tailored Classes Page 13.16 shows how mill-specific classes can be selected, if required.

13.2

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USTER® QUANTUM 3

Frequently asked questions

14

14


This paper was written to answer the questions which are asked frequently by our customers.

14.1 14.1.1

Product related questions What type of sensing principles does USTER® QUANTUM 3 offer?

USTER® QUANTUM 3 offers the choice of optical and capacitive sensing technologies for basic clearing. The foreign matter option can be added on top of the basic capacitive or optical clearing. The available measuring head types are: •

Capacitive – C15, C20

•

Optical – O30

•

Foreign matter – C15 F30, C20 F30 or O30 F30 *

*PP is an option to the C15F30, C20F30 and O30F30 measuring head see also 15-2. 14.1.2

How does the USTER® QUANTUM 3 differ from competing products?

The USTER® QUANTUM 2 was until now the market leader and the benchmark for high performance yarn clearing. The USTER® QUANTUM 3, the successor, takes yarn clearing to a next level. The system was designed bearing the needs of a range of requirements starting from basic s to the most sophisticated demands. It incorporates futuristic technology while at the same time being robust to withstand the challenging mill environment. The core of the USTER® QUANTUM is its smart clearing technology. It helps to eliminate the basic and most important challenge for spinners which is the definition of the optimum clearing limit for a variety of yarns with differing quality needs. USTER® QUANTUM 3 has simplified the complexities of yarn clearing and enables valued s to easily and fully exploit all clearer capabilities, every day. The system learns and displays the yarn body (nominal yarn with its set of tolerable frequently occurring yarn faults) in minutes and at the press of a button proposes a starting point for clearing limits with a cut forecast. Practically this is equivalent to having an USTER® specialist always beside to achieve the optimum results out of any yarn application. The new USTER® QUANTUM 3 will also amaze you with its speed and ease of use. In just two minutes, it will learn everything it needs to know about your yarn. Then, applying USTER® knowhow it will suggest the best way to achieve the quality requirements you specify, by proposing suitable clearing limits. You now only need to approve and hit the START button The USTER® QUANTUM 3 with its new foreign matter clearing concept also sets a new benchmark for contamination control. •

The new sensor technology is able to see all colors of foreign fibers and separates them into disturbing foreign fibers and mostly non disturbing vegetables to enable maximum removal of foreign fibers with minimal cuts.

Polypropylene detection is another key highlight. Founded on the new capacitive sensor technology, USTER® QUANTUM 3 sets a new benchmark for PP removal.

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14.1

14


In summary the USTER® QUANTUM 3 is the most robust and technologically advanced knowledge integrated clearer ideally suited to today’s market needs, far ahead of any competing products.

14.1.3

What are the main new functions of the USTER® QUANTUM 3?

USTER® QUANTUM 3 offers a host of new innovative features such as: Smart clearing •

Display of the real yarn body to ensure appropriate clearing limits at the lowest possible cuts

•

Fast and easy setup of appropriate clearing limits - One button proposal for clearing limits considering the yarn body and requirements as a starting point for optimization

•

Easy selection of the appropriate clearing limit with open and close buttons

•

Cut forecast for the selected clearing limit

Smart count clearing •

Detection and elimination of bobbins with wrong counts

•

Detection and elimination of short term mass/diameter variations of length ranging from 2 m to 12 m having a major negative impact on fabric appearance

Detection of periodic defects (spectrogram peaks) of multiple wavelengths Advanced splice clearing •

Synchronized to clearing limits to ensure safe quality

•

Scatter plot and numeric classification of splices to identify and eliminate rogue splicers. JRA (splice failure ratio alarm) is a perfect feature to find rogue splicers.

Foreign Matter clearing •

Detection of all colors of foreign fibers using multiple light sources

•

New foreign fiber clearing concept separating foreign matter into foreign fibers and vegetable matter. This allows the most effective and economic removal of disturbing foreign fibers ever.

Next generation of Polypropylene detection with a higher removal efficiency of PP including small PP at high cut efficiency. A new faster control clearing unit with the latest generation touch screen and an ergonomic interface The next generation Expert system with a host of smart features – The USTER® QUANTUM EXPERT 3.

14.2

USTER® QUANTUM 3


14.1.4

14

What are the new quality parameters measured by the USTER® QUANTUM 3?

The USTER® QUANTUM 3 detects short, fine thick and thin places in new classes – see picture below.

Fig. 14-1

Designation of the thick and thin places classes

Short count variations (CC) of multiple cut lengths i.e. 2 m to 12 m (For comparison: USTER® QUANTUM 2 – only one cut length) Periodic faults of multiple wavelengths All colors of foreign fibers including those with very low contrast or reflectance

Fig. 14-2

Designation of the foreign fiber and vegetable classes

Even small Polypropylene defects As always the quality data is on the same basis as the established Uster laboratory instruments

USTER® QUANTUM 3

14.3

14 14.1.5


What is the yarn count range of USTER® QUANTUM 3 and which sensing method will fulfill the quality requirement?

The USTER® QUANTUM 3 yarn count range is extended compared to the USTER® QUANTUM 2 and can be used for all staple fiber yarns from Nec 3 – Nec 200 / Tex 200 – Tex 2.9. The choice of either an optical or a capacitive sensor gives the widest application range. USTER® will assist you in the choice of sensing method best for your quality requirements.

14.1.6

What is new with the USTER® QUANTUM 3 optical basic clearer?

USTER® QUANTUM 3 comes with complete new sensor technology for all sensors including the optical basic clearing. The new optical sensor is able to see the complete yarn body and suggest clearing limits for all applications. In addition to the advanced short thick place detection, the system has new algorithms for detection of long thick and thin places and also offers the new advanced count and CC channel to detect short term diameter variations from 2 m to 12 m. Splice clearing is taken to the next level with USTER® QUANTUM 3 and the classification (numeric and graphic) is offered with the new optical clearer. As with USTER® QUANTUM 2, Q Data monitors all quality parameters such as CV, Imperfections and classification on the same basis as a the laboratory.

14.1.7

What is the difference to UQC2 Vegetable Filter?

The USTER® QUANTUM 3 separates foreign matter into three pools. It provides online classification of foreign fibers (FD and FL) as before and for the first time Vegetable Matter Classification. s can see the amount of vegetables illustrated as dense areas or from the numeric vegetable classification matrix for different cotton varieties. Another innovation is that the system provides a choice of four different clearing limit possibilities for vegetables. With this the s can choose the level of vegetable clearing needed depending on the end use.

14.1.8

What is the advantage of the USTER® QUANTUM 3 for core yarns?

The main problem with core yarns (with respect to yarn clearing) is the detection of the missing core. When a core is missing, it causes a marginal change in diameter however it causes a higher change in mass. The capacitive clearer has therefore an advantage for this application. The change in mass is proportional to the fineness of the core. The USTER® QUANTUM 3 has a new capacitive sensor technology which has an even better signal ratio and therefore a higher possibility to detect the missing core. The detection is mainly possible when the change in mass due to the missing core is greater than 5-6%.

14.4

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14.1.9

14

What is the benefit of slub yarn setting in USTER® QUANTUM 3?

The USTER® QUANTUM 3 clearing concept based on yarn body helps to easily define the boundaries for clearing disturbing defects in such yarns while retaining the slubs produced on purpose. The K-point setting will easily help to keep these purposely produced slubs away from clearing. All other defects, which might disturb the fabric appearance, can be taken out.

14.1.10 How is the PP performance of the new clearer? The USTER® QUANTUM 3 PP clearing is based on the newest sensor technology. The new PP sensor has high detection efficiency with a high cut accuracy resulting in reduction of disturbing PP in the fabric like never before. The illustration by means of the scatter plot enables to choose or fine tune the clearing limits in an easy and reliable way.

14.1.11 How are the repair costs of USTER® QUANTUM 3? USTER® products always offer high reliability and accuracy. The USTER® QUANTUM 3 also delivers on this promise. Building on the proven USTER® QUANTUM 2, the USTER® QUANTUM 3 is a tough, robust clearer which will need less maintenance and repairs and therefore lower running costs.

14.1.12 What are the advantages from a maintenance point of view? The USTER® QUANTUM 3 has a mechanical design that reduces maintenance. The foreign matter sensor is taller and wider with stable yarn path. This result in less dirt deposits and therefore needs far lower cleaning than conventional clearers. This has been proven in extensive tests in challenging environments. The electronic assembly is better shielded to prevent dust and dirt and is also better decompled from the vibrations of the cutter. This ensures higher performance stability and the enhanced lifecycle. As a result of the above, s can expect a long lasting, less maintenance demanding clearer with solid performance.

14.1.13 Can the USTER® QUANTUM 3 is installed be winders of previous generations? USTER® QUANTUM 3 with its versatile design can also be used for retrofits on older automatic winders. Please refer to the Technical Data Sheet on www.uster.com to see the list of winder models. Our sales organization will be glad to assist you in all respects.

USTER® QUANTUM 3

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14.1.14 Why does the USTER® QUANTUM 3 have a bigger housing? USTER® QUANTUM 3 is USTER’s biggest clearer to date - quite simply to fit all new robust technology. Tough on the outside, it’s completely newly designed to stand up to the most demanding mill environments and provide a long life. Like a better sealed clearer core which keeps out dirt and dust, reinforced sensors, which can cope with vibration, thermal stability etc. The new air blowing arrangements reduces dirt build-up of the sensor from both the yarn and the air supply. These QUANTUM 3’s innovations will help the clearer to work better, last longer and need less cleaning and maintenance. Another major reason is the new sensor design. The capacitive sensor; optical sensor and the foreign matter sensor all occupy more space for better performance. The foreign matter sensor for example is higher and wider than before, which reduces dirt deposits and therefore needs less cleaning and maintenance.

14.1.15 What is the purpose of the arrow LEDs on the measuring head? The LEDs as in the case of USTER® QUANTUM 2 are used to display textile or technical alarms. In case of a textile alarm – both arrows light up and in the case of a technical alarm both LEDs blink continuously The arrow LEDs is also used in the test mode to collect defects. Each arrow LED can be programmed for a specific fault type. Please refer to the operating instructions for more details about the several possibilities with the test mode – called the iMH LED function.

14.2 14.2.1

Application related questions What kind of yarn clearer do I need for my application?

It depends on the type of application. Only Uster Technologies offers the knowledge and possibility of the best capacitive and optical clearer for the monitoring and elimination of seldom-occurring thick and thin places. Both types are available with the possibility of optical clearing for foreign fiber elimination. The sales staff and specialists of Uster Technologies can help you to select the best option for your application.

14.2.2

How is it possible to simplify the definition of clearing limits?

With the USTER® QUANTUM 3 Uster Technologies has developed a completely new, easy and customer oriented way of setting the clearing limits. At first the system can be started up with existing clearing limits. After a couple of minutes of production, the USTER® QUANTUM 3 analyzes the yarn and proposes smart clearing limits as a starting point for optimization . The smart limits proposed consider the yarn body and the limits. For each smart limit the system provides a forecast of the number of cuts to be expected.

14.6

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14


In case the clearing limit proposal is not consistent with the end requirements, s can choose to open or close the setting easily with the open/close buttons or of course manually enter the settings.

14.2.3

How can one find the optimal setting for basic clearing? Is it the same as before?

With the USTER® QUANTUM 3, finding the optimal setting is easier and faster like never before. After evaluating the yarn over a few kilometers, the system proposes an optimum starting point for the clearing limits considering the yarn body, experience and requirements. At the same time the system predicts the number of cuts per 100 km to be expected for the defined limit. This is available at the touch of a button. In case the default starting point has to be changed for some reasons, s can simply choose from a range of closer or more open limits each time looking at the cuts that should be expected for the setting. Thus the optimum setting is based on the smart limits within a short time According to the quality level of the end required, the settings can be selected more open or close.

14.2.4

What is the best basic setting for my yarn?

The best setting is a compromise between quality and productivity. The USTER® QUANTUM 3 proposes an optimal starting point after a couple of minutes of production. This setting fulfils most end needs.

14.2.5

How can one find the optimum setting for good fabric appearance and for optimum productivity?

The new unique feature of the yarn body display is showing the real characteristic of the yarn for the first time. After just 30 km of yarn running, the yarn body is illustrated and optimization can already be started. If higher accuracy of cut prediction is sought one can wait for 100 km. The smart limit proposal based on the yarn body analysis and USTER® experience will ensure that the clearing will result in no major defects left and good fabric appearance.

14.2.6

Which setting shall I use to make sure that no Classimat objectionable faults will remain?

The scatter plot and the yarn body are displayed according to the classes. The USTER® QUANTUM 3 considers objectionable faults according to Classimat as a criterion when proposing clearing limits. Where needed, the clearing limits can be easily adopted manually to ensure that no major defects will remain in the yarn (to date).

USTER® QUANTUM 3

14.7

14 14.2.7


What is the USTER® QUANTUM 3 advantage with respect to compact yarns?

The USTER® QUANTUM 3 offers major advantages for compact spinners. Compact yarns are very even, and small defects can be disturbing in the fabric. USTER® QUANTUM 3 shows the complete yarn body and hence it is possible to clearly identify and remove the outliers even if they are small and fine. At the same time the unjustified cuts are minimized. Since yarn faults can easily be recognized by the human eye due to missing hairiness, the USTER® QUANTUM 3 is particularly suitable to detect small faults. Therefore the USTER® QUANTUM 3 is the most powerful clearer for compact yarns. Trials with different compact yarn producers have shown that the fabric produced out of USTER® QUANTUM 3 cleared yarn is the best. As known the monitoring of the quality parameters such as hairiness, evenness, imperfections and periodic faults is also crucial with compact yarns. The USTER® QUANTUM 3 with all these possibilities and the new periodic fault (PF) channel makes it much easier to find the fault reasons. The monitoring of the hairiness must be especially emphasized, as a higher hairiness variation results in a decrease of the yarn strength and cloudy fabric appearance.

14.2.8

When should I use the vegetable clearing?

Vegetables are part of foreign matter. However with most common bleaching processes, vegetables disappear during bleaching. Therefore mostly it is not necessary to remove them. Imagine a clearer without a vegetable filter – in this clearer one would incur cuts for removing vegetables since the clearer is not able to distinguish between vegetable and other foreign matter. Since the proportion of vegetables are rather high in some cottons this results in a substantial drop in production and at the same time limit the ability to remove real disturbing foreign fibers. The USTER® QUANTUM 3 intelligently separates vegetables from other foreign matter. This offers better selectivity in F matter clearing and save cuts significantly. The reduction of cuts is reached by allowing vegetables which will not disturb the downstream process to (they will not be cut). The feature is used for articles that will go for bleached applications.

14.2.9

Why cannot all vegetables using Vegetable Matter Clearing when they are not disturbing?

In most situations vegetables are not disturbing. However long and thick vegetables have to be removed since they can cause breaks in downstream processes. In applications where the bleaching agents are milder, vegetables do not completely disappear after bleaching and need to be treated as colored foreign fibers. Therefore they have to be removed according to the quality needs. The built in intelligence of USTER® QUANTUM 3 divides the vegetables into more or less disturbing events according to the end product requirements. This is expressed by the way of setting close, medium and open setting.

14.8

USTER® QUANTUM 3


14

14.2.10 We have an USTER® QUANTUM clearer or other clearer generations - can we copy the setting because it was acceptable until now? The USTER® QUANTUM 3 has a new easy way of setting which is nevertheless different from previous generations. Therefore, the same setting cannot be directly copied. However it is very easy to get to the same or better quality and productivity levels by following the procedure below. If the existing setting was fine until now, choose the smart limit in the USTER® QUANTUM 3 which offers the same level of cuts. This smart limit should normally be able to deliver the same or better quality. In a second step it is recommended to compare this setting with the yarn body itself to see if the setting follows the yarn body. If it does not follow the yarn body it is advantageous to choose a clearing limit that follows the yarn body. On the other hand if the setting cuts into the yarn body it is beneficial to stay away from the yarn body and save cuts. the results according to the normal quality. Make yarn boards to that all cut faults need to be removed and that the not cut faults may remain.

14.2.11 What is different with the continuous count channel? Is the settings process easier? With the USTER® QUANTUM 3 the CC (continuous count) clearing has made a substantial jump. The CC setting is now possible for multiple length channels. To make settings easier the system displays the yarn body and an optimal starting point for the settings. In a standard application a cut level for CC with about under 2.0 /100km is common. If there is a problem occurring from side of the spinning process, e.g. sliver count deviations, the clearer will identify these deteriorations and increase the cuts to ensure that only the yarn within the given limits will be wound on the package.

14.2.12 How can one set up the splice clearing curve? With the USTER® QUANTUM 3 splice clearing also has made a substantial jump. A smart possibility offered by the system is to synchronize the splice settings to the NSL T settings to avoid bad splices being ed The splice clearing curve could be placed ideally as same as the NSLT clearing limits. For highest quality requirements the Jp, Jm setting can even be set up to -5 to -10% below the NSLT clearing limit. If this will results in too many JP or Jm cuts then the rogue splicers should be identified and fixed.

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14.2.13 How can one find/identify rogue splicers? •

Use JR Splice failure ratio (miscellaneous, JR splice failure ratio)

•

Use JRA splice failure ratio alarm (group setting)

14.2.14 What FD setting should I keep for a cotton yarn? (In case of no specific requirement from the buyer) An attempt should still be made to understand the quality demand of the end to prevent claims later. As a general rule longer and very dark foreign fibers should be removed on priority. We propose using the default smart limit setting of the USTER® QUANTUM 3 together with the medium setting of the Vegetable Clearing in such situations. Depending on the cuts and from the buyer one might optimize the settings to more close or open settings.

14.2.15 USTER® QUANTUM 3 has more than 40 classes, but in USTER® QUANTUM 2, we only have 23 classes- What is the purpose of these additional classifications in USTER® QUANTUM 3?

Fig. 14-3

14.10

Designation of the thick and thin places classes

USTER® QUANTUM 3

14


Fig. 14-4


The USTER® QUANTUM 2 already offers extended classes in thick and thin places and extended classification in Foreign Fiber classification. USTER® QUANTUM 3 offers these classes and further newer classes in thick and thin places with the option Advanced Classification. The new classes were defined due to the reason that yarns have become more even and defects in these newly defined area have been seen to be causing quality claims. For the first time spinners can measure and therefore control these defects.

14.2.16 USTER® QUANTUM 3 has new sensor technology in basic and FM clearing – are the results comparable to the old classification? The new sensor for the detection of thick places and thin places is able to better determine the length and size of short thick places and the small thin places than the previous sensor. This more accurate determination for short thick places does not affect the fault categories which have to be eliminated. Foreign matter is detected by a sensor with multiple light sources which is able to deter-mine all colors with the same sensitivity because of improvements of the optical measuring system. However, the counts per category remain within the statistical variations which have to be expected for seldom occurring events when comparing with the previous measuring systems.

14.2.17 Can I use the QUANTUM 3 for wet splicer applications? The USTER® QUANTUM 3 optical clearer can be used with wet splicer without any restrictions. The capacitive clearer can be used with restrictions on the amount of water sprayed. Please USTER® for .

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For the capacitive clearer the combination with Foreign Matter option i.e. either C15/F30 or C20/F30 is required. There is a special setting on these clearers particularly assigned for the wet spliced applications.

14.2.18 Is it possible to classify foreign fibers? The USTER® QUANTUM 3 classifies foreign fibers and vegetables in the USTER® FOREIGN CLASS matrix. The faults are classified according to the reflection (%) and length (mm). The system also illustrates the frequency of foreign fibers and vegetables as dense areas to facilitate easy settings. The system provides numeric classification and the scatter plot of foreign fibers and vegetables including the dense area display.

Fig. 14-5


14.2.19 What are the experience values for cuts in ring spinning mills with foreign fiber clearers? Cuts will depend on the degree of contamination of the raw material and the quality requirements. With medium degree of contamination of the raw material and non bleached fabrics end use it could be expected that the foreign fiber cuts range between 10 to 40 cuts per 100 km. In case of bleached knitted or woven fabrics FF clearing is more critical and even higher cuts should be expected. With the new FF clearing concept, The USTER® QUANTUM 3 ensures the highest possible quality with the lowest possible cuts. The smart way of setting the clearing limits of the yarn clearer will ensure that the most disturbing fibers will always be eliminated first. Closer settings will eliminate finer and shorter faults.

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14.2.20 Can we compare the classification of C15 on C20 in USTER® QUANTUM 3 The USTER® QUANTUM 3 new capacitive sensor has shorter guarded measuring fields (4mm). As a result of the new technology, the classification of C15 and C20 is comparable. This means the clearing limits can be similar between these clearer types and the cuts, clearing performance for C15 or C20 is comparable. s can now choose the most appropriate iMH type for their application.

14.2.21 Is the USTER® QUANTUM 3 classification comparable to the USTER® STATISTICS? The Quality Data such as the coefficient of variation of the yarn evenness, the thick places, thin places, classification results and hairiness can be compared with the USTER® STATISTICS. It has to be taken into consideration, however, that the environmental conditions are not the same on the machine and in the laboratory, and, therefore, we have to compare the figures with more tolerance than between two laboratory systems.

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USTER® QUANTUM 3

Technical specifications

15


15.1

Basics of USTER® QUANTUM 3

15

Fig. 15-1

15.1.1 Architecture The USTER® QUANTUM 3 is a yarn clearing and monitoring system for winding machines consisting of: 1. Central Clearing Unit 6 (CCU6). One control unit per winder. All settings and operational check of each position are made from the Central Clearing Unit - Standalone on all winders except Oerlikon Schlafhorst Autoconer 5 and X5 - Integrated with winder Informator on Oerlikon Schlafhorst Autoconer 5 and X5 2. Intelligent clearer measuring heads (iMH) for each winding position. 3. Interface to the winding positions and connecting cables.

15.1.2 Scope of application Yarn types:

For all spun yarns consisting of natural fibers, blended fibers, synthetic fibers and plyed yarns.

Languages:

GB, CN, TR, VN, DE, FR, IT, ES, PT

Count range:

Nec 3 to Nec 200 / Nm 5 to Nm 340 / 2.9 to 200 tex

Maximum speed:

2200 m/min

General Ambient conditions:

- Temperature range +5 to 50°C / 41 to 122°F - Humidity up to 95%, not condensing

15.1.3 Scope of supply iMH for each position, Central Clearing Unit 6 (CCU6), Documentation, Tools, Yarn Boards, Yarn Grades

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15.1

15


15.1.4 Miscellaneous Printer:

USB Printout or via an optional portable printer

Access Rights:

Controlled through programmable s

Unit system:

Nec, New, Nm, Tex

15.2

Structure of the USTER® QUANTUM 3

15.2.1 Features of USTER® QUANTUM 3 and options Table 15-1 shows the individual features of the options. OPTIONS

FEATURES

COMMENTS

Yarn Body (N, S, L, T, CC)

Visualization of the yarn characteristics

Smart limits (N, S, L, T, CC)

A proposed starting point for clearing limits

Scatter plot (N, S, L, T, C, CC, J)

Visualization of the thick and thin places, count deviations and splices.

N, S, L, T

Elimination of the disturbing thick and thin places

C, CC

Count deviation clearing and monitoring

Jp, Jm

Splice Clearing

Cut forecast

A forecast of cut numbers per 100 km

Technical alarms

Alert for technical problems

Textile alarms

Alert for textile problems

Dense Area (FD, FL, VEG)

Identification of range where foreign fibers are located

Smart limit (FD)

A proposed starting point for foreign fiber clearing limits

Scatter plot (FD, FL)

Visualization of dark and light foreign fibers

Dark foreign matter (FD) Light foreign matter (FL)

Elimination of dark and light foreign fibers

On-line foreign matter classification


Identification of vegetables

Separation of vegetable matter

On-line vegetable classification

Classification of vegetable matter

Polypropylene fibers (Option)

Smart limit (PP)

A proposed starting point for polypropylene clearing limit

Scatter plot (PP)

Visualization of polypropylene fibers

Q-Data (Option)

Evenness (CV)

Determination of the yarn evenness

Imperfections

Determination of the frequent thick places, thin places and neps

Basic on-line classification (NSLT, FD, J and VEG)

Classification of disturbing thick and thin places, foreign fibers, splices and vegetables

Class alarms

Triggering of alarm if the number of disturbing faults has exceed the selected number of faults

Periodic Faults (PF)

Detection of periodic faults

Basic clearing

Foreign matter Vegetable Clearing (Option)

15.2

USTER® QUANTUM 3

15


OPTIONS Hairiness (Option) Expert (Option) Advanced Classification (Option) Lab On-line (Option) Table 15-1

FEATURES

COMMENTS

Absolute hairiness measurement

Determination of the hairiness value

Exception spindle detection

Recognition of spindles with excessive hairiness

Expert

Access to the data output for Expert System and centralized data collection and reporting

Extended Classes

Classification of additional classes in NSLT, F, VEG

Tailored classes

Classes can be selected by customers

Software pack

Software pack consists of Hairiness, Advanced Classification and Expert

Features of Basic Clearing and options

15.2.2 Features versus measuring head types Table 15-2 below describes what type of USTER® QUANTUM 3 sensor for each measuring head is appropriate for which kind of application. ®


FEATURES

MEASURING HEAD TYPES

Capacitive C15

Capacitive Capacitive C20 C15 F30

Capacitive C20 F30

Optical O30

Optical O30 F30

BASIC

X

X

X

X

X

X

FOREIGN MATTER (Option)

---

---

X

X

---

X

VEGETABLE (Option)

---

---

X

X

---

---

POLYPROPYLENE (Option)

---

---

O*

O*

---

---

Q-DATA (Option)

O

O

X

X

O

X

HAIRINESS (Option)

---

---

O

O

---

O

USTER QUANTUM EXPERT 3

O

O

O

O

O

O

ADVANCED CLASSIFICATION (Option)

O

O

O

O

O

O

LAB ONLINE (Option)

---

---

O

O

---

O

®

Table 15-2

®

The USTER QUANTUM 3 sensors and options

USTER® QUANTUM 3

15.3

15


Key: X

This feature is included in this version of the sensor

O

Product Option Key (POK) is needed to have access to the feature mentioned in the header of this column

O*

Hardware upgrade required in the Central Clearing Unit 6 (CCU6) to have access to the feature

---

Not available with this iMH type

15.3

Comparison, capacitive versus optical measuring principle for basic clearing

Table 15-3 shows the comparison capacitive versus optical measuring principle for basic clearing. In the following table there are a few remarks to the selection of the clearer type.

OPTIONS

Capacitive principle

Optical principle

Basic difference

A capacitive measuring signal is proportional to the cross-section of a yarn

An optical measuring system is proportional to the diameter of a yarn

Sensitivity

A thick place with 3 times more fibers in the cross-section than average produces a signal of +200%

A thick place with 3 times more fibers in the crosssection than average produces a signal of +73% (Exception: N, S faults)

Application range

For most of the yarns the capacitive principle can be utilized.

For all the yarns the optical principle can be utilized.

Contamination

The capacitive system needs less cleaning of the measuring zone. Particularly useful in dirty environments

The optical system needs more cleaning of the measuring zone

Exception 1: Conductive fibers

The capacitive system is affected by conductive fibers and should not be utilized for such yarns

The optical system is not affected by conductive fibers

Exception 2: Dyed yarn

The capacitive system is not affected by color variations

The optical system is affected by color variations

Exception 3: Wet splicing

It is recommended to minimize the amount of water used for splicing to protect the clearer and the machine.

The optical system is recommended

Exception 4: Wet spun linen

Not recommended

The optical system is recommended

Table 15-3

15.4

Comparison capacitive versus optical measuring principle for basic clearing

USTER® QUANTUM 3


15.4

15

Winding machines

Table 15-4 shows the winding machines on which the USTER® QUANTUM 3 can be used: Manufacturer

New machines

Retrofit

Murata

Murata PC 21

Murata PC 21

Oerlikon Schlafhorst

Oerlikon Schlafhorst Autoconer AC5 and AC X5

Oerlikon Schlafhorst Autoconer 338

Savio Orion

Savio Espero

Savio Polar

Savio Orion

Savio

Oerlikon Schlafhorst Autoconer AC5 and AC X5

Savio Polar Qingdao

Qingdao Smaro

Qingdao Smaro

Table 15-4

15.5

Count range of the USTER® QUANTUM 3

iMH-C15 iMH-C20 iMH-O30 Option F30 Option PP

Nec 3 Nm 5 200 tex

Nec 6 Nm 10 100 tex

Nec 12 Nm 20 50 tex

Nec 30 Nm 50 20 tex

Nec 60 Nm 100 10 tex

Nec 80 Nm 135 7,4 tex

Nec 100 Nm 170 5,9 tex

Nec 200 Nm 340 2,9 tex

Fig. 15-2

USTER® QUANTUM 3

15.5

15 15.6


Architecture, sensor principles and configuration

Subject Architecture of clearer

Characteristics

Technical specification

Intelligent measuring head

Comment Signal processing unit integrated in each measuring head, no separate evaluation unit anymore, high interference suppression, high accuracy due to the self-check of the system.

Sensor prinMass variation ciples for Diameter variation basic clearing

Length of measuring zone: Mass variation: 4 mm Diameter variation: 3 mm

Physical principles: Mass variation: capacitive Diameter variation: optical

Sensor principle for foreign fiber detection and monitoring of the hairiness

Length of measuring zone: 2 mm

Physical principle:

Measurement of phase shift of 2 different materials

Length measurement of polypropylene fibers is possible.

Reflectance

Sensor for Phase angle polypropylene detection Sensor configurations

Basic clearing: Capacitive or optical

optical

Physical principle: capacitive Same measuring head dimensions for all sensor configurations

Basic and foreign fiber clearing: Capacitive and optical; Optical and optical

Table 15-5

15.6

USTER® QUANTUM 3

15


15.7

Elimination of disturbing yarn faults

Subject

Elimination of disturbing thick and thin places

Quality Abbreviation characteristics Short thick places Long thick places Thin places

Wrong bobbin (count variation during start up) Elimination of wrong counts

Long thick- and thin place (count variation during winding process)

Elimination of periodical Periodical faults faults Dark foreign fibers in light yarns Elimination of foreign fibers

Vegetable material

T

Options needed

Comment

0*/1...900%

0…200 cm

Basic

The clearing curve can be optimized by means of 8 setting points for NSL faults.

0*/-1…-100%

0…200 cm

Basic

2...100 m

Basic

0*/+1...80%

Cm

0*/-1...-80%

C 1

0*/+1...+150%

C 2

0*/+1...+150% 12 m (default)

The clearing curve can be optimized by means of 8 setting points for T faults.

2 m (default)

Basic

Monitoring of long thin- and thick places

CCm 1

0*/-1...- 80%

2 m (default)

CCm 2

0*/-1...- 80%

12 m (default)

PF

0*/50...100%

---

Q

Furthermore, setting of the number of periods: 5 – 500

FD

0*/3...100%

0...10 cm

F

There are 8 setting points each for the FD channel

F

There are 4 different modes: Close, medium, open and ‘as FD’

VEG

Close, medium, open and ‘as FD’


PP

0*/3 … 100%

Avoidance of thick ts

Jp

0*/-20…+30%

Basic

Adjust to NSL

Avoidance of thin ts

Jm

0*/-20…+30%

Basic

Adjust to T

Jp

0*/1…900%

0…10 cm

Basic

There are 8 setting points each for Jp

Jm

0*/-1…-100%

0…10 cm

Basic

There are 8 setting points each for Jm

CY

0*/5…80%

Elimination of bad ts Avoidance of thick ts Avoidance of thin ts Core missing

NSL

Reference length

Sensitivity

Core Yarn

0...10 cm

PP

Available with both C15F30PP and C20F30PP clearers

Basic

Table 15-6

Abbreviation: Q = Q-Data

F = Foreign fibers

USTER® QUANTUM 3

PP = Polypropylene

0* = Inactive (off)

15.7

15 15.8


Supervision of the machine operations

The supervision of the machine operations depends on the requirements of the machine manufacturers.

Subject

Quality Abbreviation characteristics

Supervision Avoidance of of the splice splice failures failure ratio Supervision of upper yarn during t operation

Avoidance of double yarns from the cone side

Supervision of the drum wrap

Avoidance of yarn wounds on the guide drum

Sensitivity

Reference length

Options needed

JRA

0*/1…100%

---

Basic

U

0*/10...200%

---

Basic

DWM

---

---

Basic

Comment

All winding machine types if needed

Table 15-7

0* = Inactive (off)

15.8

USTER® QUANTUM 3

15


15.9

Determination of quality characteristics

All quality characteristics are monitored continuously at every production position. These quality characteristics can be monitored at any time.

Subject


Abbreviation


Options needed

Comment

Coefficient of variation, per group

CV-MV

50 ... 10'000 m, 0*/0.1…99%

Q

No substantial variation when changing the evaluation length. Measurement can be started at bobbin change or can be done continuously.

Coefficient of variation per position

CV-SP

50 ... 10'000 m, 0*/1… 99%

Q

No substantial variation when changing the evaluation length.

Imperfections:

IPI

Evaluation length: 50…2000m

Alarm limit: 0*/1…64’000

Setting thresholds • frequent thin places

-30/-40/-50/-60%

Q

• frequent thick places

35/50/70/100%

Q

• frequent neps

140/200/280/400%

Q

Length classes A to G: 0.2 – 1 cm, 1 – 2 cm 2 – 4 cm, 4 – 8 cm, 8 – 16 cm, 16 – 32 cm 32 – 64 cm, > 64 cm

Determination of quality characteristics Classification of thick and thin places

CMT

Thick place classes: 30 – 45%, 45 – 75%, 75 – 100%, 100 – 150%, 150 – 250%, 250 – 400%, > 400%

Imperfections are always displayed per 1000 m (reference length)

Total number of yarn faults per class (absolute) and relative per 100 km 30 thick place classes and 15 thin place classes.

Q, A

Thin place classes: H0, H1, H2, I0, I1, I2, TB1, TB2, TC1, TC2, TD2, TD1, TD”: -20..-30%, -30...-45%, < -45% Periodic faults Number of disturbing thick and thin places Wrong count

USTER® QUANTUM 3

PF

As defined in chapter 15.7

Q

Total number of yarn faults per class (absolute) and relative per 100 km

N, S, L, T


Basic

Total number of eliminated yarn faults per class (absolute) and relative per 100 km

, Cm


Basic

Total number of eliminated yarn faults(absolute) and relative per 100 km

15.9

15



Abbreviation


Options needed

Comment

Count deviation and monitoring of uneven long thick and thin places

C, CCm


Q

Total number of eliminated yarn faults (absolute) and relative per 100 km

FD

Length classes A to F: 0.1-0.6cm, 0.6-1cm, 1-1.4cm, 1.4-2cm, 2-3cm, 3-5cm, 5-7cm, >7cm

Subject


F

Total number of foreign fibers per class (absolute) and relative per 100 km 32 displayed foreign fiber classes.

Reflectance classes: 5-7%, 7 – 10%, 10 – 20%, 20 – 30%, 30 – 100%

1 table for FD,

Foreign fibers, grey or colored yarns

FD


F

Total number of eliminated yarn faults per class (absolute) and relative per 100 km


PP


PP

Available with both C15F30PP and C20F30PP clearers

Length classes A to F: 0.1-0.6cm, 0.6-1cm, 1-1.4cm, 1.4-2cm, 2-3 cm, 3-5cm, 5-7 cm, >7cm Vegetable clearing

VEG

F

Total number of vegetable matter per class (absolute) and relative per 100 km 32 displayed vegetable matter classes.

Reflectance classes: 5-7%, 7-10%, 10-20%, 20-30%, 30-100% Hairiness per group

H-MV/

50 ... 10'000 m, 0*/0.1...20

H

Hairiness per winding position

H-SP

50 ... 10'000 m, 0*/0.1...20

H

Measurement can be started at bobbin change or can be done continuously. The test length per bobbin can be selected.

Q

Deviation in length and percent from the nominal value are displayed.

Splice classification

J

0...10 cm -100…900%

J-Classes as NSLT

Table 15-8

Abbreviations: Q = Q-Data

H

= Hairiness

A

= Advanced Classification

F = Foreign fibers

PP

= Polypropylene

0*

= Inactive (off)

15.10

USTER® QUANTUM 3

15


15.10 Cut alarms, Quality alarms, Special Counters and Logbook Choices

Subject

Abbreviation

Settings

Reference length

Options Comment needed

Yarn fault alarms

Short thick places

NSA

0*/1...99

1...999 km

Basic

Long thick places

LA

0*/1...99

1...999 km

Basic

Thin places

TA

0*/1...99

1...999 km

Basic

Wrong count

CA

0*/1...99

1...999 km

Basic

Count deviation and uneven, long thick and thin places

CCA

1...999 km

Basic

Foreign matter

FA

1...999 km

F


PPA

1...999 km

PP

iMH C15F30 and C20F30 with option PP

Periodic faults

PFA

1...999 km

Q

Monitoring of the fault frequency

Splice failure ratio alarm

JRA

0*/1…100%

---

Basic

Monitoring of the frequency

Coefficient of variation, CV-MV mean of entire machine or article

upper: 0*/0.1...99%

0,05...10 km

Q

Absolute monitoring of the CV-MV; upper and lower limit.

Coefficient of variation per position

upper: 0*/1...99%

0,05...10 km

Q

Relative deviation of the CV-MV value

0,05...10 km

H

Absolute monitoring of the H-MV value; upper and lower limit.

0,05...10 km

H

Absolute deviation of the HMV value

(ALARM)

QRegistration Q-Blocking Q-Cut (Ejection) Q-Blocking / Sucking

Monitoring of the fault frequency

0*/1...99

CV-SP

0*/1...99 0*/1...99 0*/1...99

lower: 0*/0.1...99%

lower: 0*/1...99% Hairiness, mean value of the group

H-MV

Hairiness per winding position

H-SP

upper: 0*/0.1...20 lower: 0*/0.1...20 upper: 0*/0.1...20% lower: 0*/0.1...20%

Special Counters

Class Alarm

CMT

Up to 5 classes Alarm limit 0*/1...64'000

1...300 km

Q

5 individual classes for alarm monitoring can be selected

Frequent neps

IP

0*/1...64000

0.05...10 km

Q


Frequent thick places

IP

0*/1...64000

0.05...10 km

Q


Frequent thin places

IP

0*/1...64000

0.05...10 km

Q


Tailored classes (NSL) tNSL

0*/5…900%

0.1…200 cm

A


Tailored classes (T)

tT

0*/-5…-100%

0.1…200 cm

A


Tailored classes (FD)

tFD

0*/5…100%

0.1…10 cm

A


Tailored classes (FL)

tFL

0*/5…100%

0.1…10 cm

A


Upper yarn cuts

U

0*/10...200%

Machine-associated

A

---

Basic Monitoring of the frequency

USTER® QUANTUM 3

---

Basic

15.11

15


Choices

Subject

Abbreviation

Settings

Reference length

Options Comment needed

additional cuts

Logbook

Yarn jump monitoring / registration/ alarm

JPM / JPM reg --/ JPA

---

Basic

Drum wrap monitoring / registration/ alarm

DWM DWM reg /DWA

---

---

Basic

Drum signal monitoring

DSM

---

---

Basic

Special cuts

SPC

---

---

Basic

Recording of all changes and alarms

Logbook ---

---

Basic

/

Monitoring of the logbook entries

Table 15-9

Abbreviations: Q

= Q-Data

F

= Foreign fibers

H

= Hairiness

PP = Polypropylene A

= Advanced Classification

0* = Inactive (off)

15.12

USTER® QUANTUM 3


15

15.11 Reports Table 15-10 shows various reports. Reports can be transferred to an USB stick or to an optional printer. Per position

Per group

Display

Printout

Display

Printout

Necessary options

Winding speed

---

---

---



Basic

Produced yarn length



*





Basic

Settings

Setting of the clearing- and alarm parameters

---

---





Basic

Yarn Faults

Number of all yarn faults YF absolute



---





Basic

Number of all yarn faults YF / 100 km



*





Basic

Number of all yarn ts YJ / absolute



---





Basic

Number of all yarn ts YF / 100 km



*





Basic

Number of N, S, L, T, , Cm, C, CCm absolute



---





Basic

Number of N, S, L, T, , Cm, C, CCm / 100 km



*





Basic

Periodic Faults absolute



---





Q

Periodic Faults / 100 km



*





Q

Foreign fibers, grey or colored yarns, FL, FD absolute



---





F

Foreign fibers, grey or colored yarns, FL, FD / 100 km



*





F

Polypropylene fibers PP, absolute



---





PP

Polypropylene fibers PP / 100 km



*





PP

Faulty yarn t Jp, Jm absolute



---





Basic

Faulty yarn t Jp, Jm / 100 km



*





Basic

Cuts U, JPM, SPC, DSM, DWM absolute



---





Basic

Cuts U, JPM, SPC, DSM, DWM / 100 km



*





Basic

Yarn fault alarms NS, L, T, F, C, CC absolute



---





Basic

Yarn fault alarms NS, LT, F, C, CC /100km



*





Basic

Periodic Faults alarm PF absolute



---





Q

Periodic Faults alarm PF / 100 km



*





Q

Groups Machine data

Yarn Fault Alarms

Yarn Fault Alarms

Feature

USTER® QUANTUM 3

Comment

List of reports: Per shift, per day, per article Intermediate report / present shift Last shift (can also be configured as automatic report)

15.13

15


Per position

Q Alarms

Printout

Display

Printout

Necessary options

Number of CV alarms CVp, CVm absolute



---





Q

Number of CV alarms CVp, CVm / 100km



*





Q

Number of Hairiness alarms Hp, Hm absolute



---





H

Number of Hairiness alarms Hp, Hm / 100km



*





H

Number of Class-alarms absolute



---





Q

Number of Class-alarms / 100 km



*





Q

Number of Imperfection alarms absolute



---





Q

Number of Imperfection alarms / 100 km



*





Q



*

---

---

Basic

Exceptions: F, VEG, PP



*

---

---

F

Exceptions: CV, IP, Class, (H)



*

---

---

Q

Coefficient of variation per group CV-MV

---

---





Q

Coefficient of variation per position CV-SP



*

---

---

Q

Mean imperfection counts 12 in different classes / 1 km









Q

Classification of NSLT faults / 100 km, absolute



---





Q, A

Classification of FD-faults / 100 km, absolute



---





Q, F

Classification of FL-faults / 100 km, absolute



---





Q, F

Classification of VEG-faults / 100 km, absolute



---





Q, F

Hairiness, mean value of the group H-MV

---

---





H

Last value of the hairiness per winding position H-SP



*

---

---

H

Yarn faults (N, S, L, T, C/CC, F, VEG, PP, PF)

 **

 **

 **

 **

Basic, F, PP

Textile alarms (NS, L, T, C/CC, F, Q, PF) Blockings/Cuts/Registrations)

 **

 **

 **

 **

Other

 **

 **

 **

 **

Feature

Exceptions Exceptions: yarn faults, textile alarms, J, JR, yarn length SP

Q Data

Event reports

Per group

Display

Groups

Comment

Yarn faults are also displayed Basic, F, Q, showing size, H, A intensity and classification. Basic

Table 15-10

15.14

USTER® QUANTUM 3

15


Abbreviation: Q = Q-Data

F = Foreign fibers

H = Hairiness

PP = Polypropylene

A = Advanced Classification



Available

*

Available if exceptions are defined and “Print all SP (spindle positions)” is selected in the menu “Configuration- Exceptions”.

 ** Available if events are defined and selected in the menu “Configuration-Event report”. ---

Not available

15.12 Clearing of various yarn types

Cotton, carded, combed, compact ring

X*

X

Blended, short staple

X

X

Synthetics, short staple,100%

X

X

Cellulosics,100%

X

X

Woolen

X

X

Worsted

X

X

Blended, long staple

X

X

Synthetics, long staple,100%

X

X

Flax,linen, hemp

X

X

Wet spun linen

X

Spun Silk

X

X

Technical yarns, non-conductive

X

X

Technical yarns, conductive

O30/ F30

Optical, O30

*PP option

C15/ F30 C20/F30

®


Capacitive C15,C20

Table 15-11 shows the application range of the clearer types according to various yarn types:

X

Table 15-11

* For cotton yarns the polypropylene feature can be applied with clearer types C15/ F30 and C20/F30.

USTER® QUANTUM 3

15.15

15


15.13 Recommendations how to use clearers 15.13.1

Sensor systems versus end use of yarn

The following tables shall give some guidelines what kind of iMH should be recommended. The asterisks in the tables have the following significance: ***** Highly recommended ****

Recommended

***

Recommended. Limitations for some applications.

**

Can be used for this application, but expertise of an Uster specialist recommended

*

Should not be used for this application without the expertise of an Uster specialist

---

Should not be used for this application

Important note: Guidelines for selling USTER® QUANTUM 3: Most of our customers want to keep the type of sensors which are installed on their machines because they may have achieved the best results with this type of sensor. Therefore, it makes sense to continue with the same sensor principle.

Type of yarn

Cotton yarns

Count range Ne All yarn counts

1 Ply yarns

2

3

Blended yarns

End use

IMH-C

IMH-O

IMH with F

Weaving / Knitting

*****

*****

*****

Same color / 2 ply

*****

*****

***

Different colors / 2 ply

*****

***

---

3 ply and more

*****

****

---

*****

*****

***

*****

*****

***

Grey

*****

*****

***

Dyed

*****

***

***

All yarn counts

100% Synthetic yarns Worsted yarns worsted/ synthetics blended yarns

15.16

Recommendation for sales engineers For all winders with wet splicers (ask Uster specialists) Detection of foreign fibers in ply yarns causes more ply-ts

USTER® QUANTUM 3

15


Type of yarn

4

Melange (Blended yarns with long staple fibers of different colors)

Count range Ne

All yarn counts and blends

End use

Blending of colored fibers at drawframe

Blending of colored fibers at spinning machine Sewing threads

5

Core yarns

All yarn counts

*****

IMH-O

*****

IMH with F

Recommendation for sales engineers

****

Short yarn defects are mostly of the same color and appear as small spots The mass deviation of the missing colored fibers are very small but the visual impact can be significant

**

***

****

*****

*****

*****

Yarns for industrial use and with a core of more than 14 % of the total mass

*****

---

***

With Lycra as core

*****

***

*****

****

****

***

Challenges depend on the end use

***

Mostly the missing slubs are a problem and, therefore, the visual appearance is most important.

---

Capacitive sensors are unable to measure metallic fibers or highly conductive fibers correctly.

DREF yarns

All yarn counts

7

Slub yarns

All yarn counts

Fancy fabrics

8

Antistatic yarns, yarns containing metallic fibers

All yarn counts

Technical fabrics as well as safety cloth

6

IMH-C

*****

---

*****

****

The biggest problem is the missing core since the yarn does not break. Such defects can only be detected with iMH-C.

Linen, flax, hemp yarns

***

*****

---

Should customer already successfully use C-type clearers, iMH-C can be offered

Linen (wet spun)

---

*****

----

Use only optical clearer for wet spun yarns

10

Spun silk

****

****

*****

11

Filament yarns

***

***

---

9

Ask Uster specialists before offering and send samples for investigation

Table 15-12

USTER® QUANTUM 3

15.17

15


15.13.2

Poor environmental conditions

The demand for detecting yarn count deviations is raising constantly. The conditions for the clearers must be constant in order to guarantee the quality requirements. The choice of the correct measuring system is very important. Especially when using the USTER® QUANTUM 3 as a retrofit solution the environmental condition plays a key role in order to exploit all the features of this clearer. Take into consideration that the customer expects a better performance when changing to a new clearer. Room conditions

IMH-C

IMH-O

IMH with F

Recommendation for sales engineers

****

*****

*****

When the winding room is separated from the spinning department the air humidity can fluctuate rapidly

Water spraying only

**

*****

*****

The moisture of the yarn and the humidity can fluctuate rapidly

Floor watering only

***

*****

*****

The humidity can fluctuate rapidly

1

Bad or no airconditioning

2 3

Table 15-13

15.18

USTER® QUANTUM 3

Appendix

16

Appendix

16.1

Standard settings

16

The following standard settings should assist when setting clearer for short staple yarns and their blends.

16.1.1 Standard settings for the capacitive clearer – Capacitive Default

Fig. 16-1

Standard settings

USTER® QUANTUM 3

16.1

16

Appendix

16.1.2 Standard settings for the optical clearer – Optical Default The following standard settings should assist when setting clearer for short staple yarns and their blends.

Fig. 16-2

16.2

Standard settings

USTER® QUANTUM 3

Appendix

16.2

16

Abbreviations

A

Machine-related additional cut

A0...A4

Classimat classes

V

Analog Digital Mean Value

B0...B4

Classimat classes

BC

Board Computer

BI

Built in

C

Yarn Count deviation during start-up (wrong bobbin)

C0...C4

Classimat classes

CA

Yarn Count Alarm during start-up

CC

Yarn count fault during operation (Continuous Count)

CCA

Yarn count alarm during operation (Continuous Count Alarm)

CCm

(CC-) Lower tolerance limit for yarn count faults during operation

C

(CC+) Upper tolerance limit for yarn count deviations during operation

C1..2

Setting point for CC

CCU 6

Central Clearing Unit 6

Cm

(C-) Lower tolerance limit for yarn count faults during start-up (m = minus)

CMT

Yarn fault classification

CMTA

(4 cm fault classification Alarm) named as “Class Alarm”

(C+) Upper tolerance limit for yarn count faults during start-up (p = plus)

CSA

Clearer Spindle Adapter (interface to machine)

CSG

Communication central clearing unit (iMH bus connection)

CTM

Cut Monitoring

CV

Coefficient of Variation of yarn evenness

CVA

Coefficient of Variation of yarn evenness Alarm

CV-MVAm

CV Mean Value Alarm -

CV_MVAp

CV Mean Value Alarm +

CY

Core Yarn

D0...D4

Classimat classes

DEF

Defined (Status of the article)

DSM

Drum Signal Monitoring

DWA

Drum Wrap Alarm

DWM

Drum Wrap Monitoring

DYD

Dynamic Yarn Detector

USTER® QUANTUM 3

16.3

16

Appendix

E

Classimat class

EHR

Machine (unit) computer (Schlafhorst)

F

Foreign matter

F, P21 .. 22

Classimat classes

FA

Foreign matter Alarm

FD

Foreign matter Dark (dark fiber in light yarn)

FD1... FD8

Setting Points for Foreign matter Dark (dark fiber in light yarn)

FL

Foreign matter Light (light fiber in dark yarn)

FL1... FL8

Setting Points for Foreign matter Light (light fiber in dark yarn)

FMA

Foreign matter sensor Monitor Alarm

G, GP21 .. 22

Classimat classes

GR

Group

GUI

Graphic interface

H

Hairiness

HA

Hairiness Alarm

H-MVAm

H Mean Value Alarm -

H-MVAp

H Mean Value Alarm +

H0...H2

Classimat classes

I0...I2

Classimat classes

iCSA

Intelligent Clearer Spindle Adapter

iMH

Intelligent Measuring Head

iMH-C

Measuring head, Capacitive

iMH-F

Measuring head with Foreign matter detection

iMH-O

Measuring head, Optical

INF

Informator (Schlafhorst)

IPI

Imperfections

J

(Splice Clearing), t (yarn splice/knot/piecing/connection)

Jm

Lower tolerance limit for yarn ts

Jm1... Jm 8

Setting Points for Lower tolerance limit for yarn ts

Jp

Upper tolerance limit for yarn ts

Jp1... Jp 8

Setting Points for Lower tolerance limit for yarn ts

JPA

Jump Alarm (yarn)

JPM

Jump Monitoring (yarn)

JR

Splice failure Rate

JRA

Splice failure Rate Alarm

K1...K3

Slub yarn auxiliary setting point

16.4

USTER® QUANTUM 3

Appendix

L

Long thick place ≥ 8 cm

LA

Long thick place Alarm

LED

Light Emitting Diode

...m

Minus

MA

Machine

MMI

Man Machine Interface (keyboard, display, printer)

MV

Mean Value

N

Very short thick places (N) < 1 cm

NS

Very short thick places (N) and Short thick places

NSA

Very short thick places (N)and Short thick places Alarm

NSL

Very short thick places (N) and Short thick places and Long thick places

16

NSL1... NSL 8 Setting points for very short thick places (N)and Short thick places (NSL) ...p

Plus

P1...P8

Setting Points

PF

Periodic yarn Fault

PFA

Periodic yarn Fault Alarm

PP

Polypropylene clearing

POK

Product Option Key

PPA

Polypropylene Alarm

PP1... PP 8

Setting Points for Polypropylene clearing

PROD

Production (State of the article)

Q-Data

Quality data

S

Short Thick place 1 cm, < 8 cm

SEED

Seed coat fragments

SP

Spindle/Spinning Position/Winding position

SPC

Special cut

SP-CTR

Spindle controller (Savio)

STAT

Status

SW

Software

SYD

Static Yarn Detector

T

Thin place

T1... T 8

Setting Points for Thin places

TA

Thin place Alarm

TB1…2

Classimat classes

TC1…2

Classimat classes

TD0…2

Classimat classes

USTER® QUANTUM 3

16.5

16

Appendix

TM

Top Mounted

tNSL

tailored class for NSL

tFD

tailored class for FD

tFL

tailored class for FL

tT

tailored class for T

U

Upper Yarn

UQC

USTER® QUANTUM 3

VEG

Vegetable matter clearing

YA

Yarn fault Alarm

YB

Natural Yarn Breaks

YD

Yarn Detector

YF

Yarn Fault

YJ

Yarn t (Splice)

ZPM

Zero Point Monitoring

Nec

English cotton count

Nm

Metric cotton count

tex

Metric cotton count (SI unit)

16.6

USTER® QUANTUM 3

16

Appendix

16.3

Explanation of

Advanced classification Article

Article change

Board computer Bobbin C-channel Clearer

The option which includes extended classes and tailored classes. The article is an identification of the yarn. It is identified by: Article number, article name and yarn count. From the point of view of the yarn clearer manufacturer, the article is also defined by the combination of all clearing settings. Operation-specific function, which involves one or several of the following items: - delete the collected article data; set the counters to zero - adjust the basic sensitivity to the new yarn of the group - enter the new settings in the USTER® QUANTUM 3. Computer of the winding machine. Type of yarn package used in ring spinning. Fault channel for the detection of yarn count deviation. Sensor and evaluation electronics of a winding position.

Clearer cut

Cutting of the running yarn to eliminate a disturbing yarn fault or a disturbing foreign fiber.

Clearer cut blocking

A signal generated by the winder, which prevents a clearer cut, e.g.: - during the splicing/knotting cycle, - when the cone is full and being changed.

Clearer group

See group

Clearing limit

Separation line between yarn faults which may remain in the yarn and those which have to be cut by the clearer. The clearing limit is defined by the setting of the sensitivity and the reference length for the respective fault channel. For the setting of the fault channels, the clearing limit is shown in the display of the USTER® QUANTUM 3 unit. For technical reasons, the clearing limit is subject to a certain tolerance.

CMT matrix Cone

Representation of the yarn faults in the 23 fault classes of the USTER® CLASSIMAT system. Cylindrical or conical yarn package produced at each winding position of a winding machine.

Central Clearing unit

Component of the yarn clearing installation. Some functions: - centralized operation of the installation - data exchange with the iMHs - output of information and results by display and USB-connection

Cross-sectional deviation

Deviation of the yarn cross-section from the mean yarn value.

Cut forecast

USTER® QUANTUM 3

A forecast of the number of cuts per 100 km.

16.7

16

Appendix

Dense Area Diameter deviation Display Double thread Extended classes Evaluation unit

Identification of range where foreign fibers are located. Deviation of the yarn diameter from the mean yarn diameter. Display at the USTER® QUANTUM 3 central clearing unit. Shows the dialog between the and the operating program. Two single threads or a faulty yarn spun from two rovings with approximately double the cross-section of the single thread. Classification of additional classes in NSLT, F, VEG -

Fault channel Group

Guide drum signal

iMH intelligent measuring head

Interface L-channel Lab On-Line Machine computer Mass deviation Material Measuring field

16.8

evaluation of the yarn signals for the yarn fault detection, provided by the measuring head issue of a cut command to the measuring head (or the winding machine) in the event of a disturbing yarn fault signal exchange with the winding position, e.g.: cut blocking, electronic yarn detector, etc.

The yarn faults are detected according to the reference length and the sensitivity in different fault channels. (setting group, clearer group) Consecutive number of spindles which have - the same measuring head type - producing the same yarn and use the same settings Electrical signal consisting of a pulse sequence. The pulse frequency is equivalent to a multiple of the circumferential speed of the guide drum. The guide drum signal is used, among other things, for the calculated adjustment of the fault reference length to the yarn count. Part of the USTER® QUANTUM. Some of the functions are: - conversion of the yarn mass or yarn diameter in a proportional electrical signal - evaluation of the yarn signals for the yarn fault detection, provided by the measuring head - issue of a cut command to the cutter (or the winding machine) in the event of a disturbing yarn fault - signal exchange with the winding position, e.g.: cut blocking, electronic yarn detector, etc. Permits the exchange of data between different systems. Fault channel for the detection of long thick places. Software pack consists of Hairiness, Advanced Classification and Expert. See board computer Deviation of the yarn mass from the mean yarn value. Raw material of the yarn. Material in pure form or as a blend of different materials used for the production of yarns. Part of the measuring head which converts the yarn measurement into an electrical signal.

USTER® QUANTUM 3

16

Appendix

N-channel Nep OEM

Periodic Faults Reference length Release Reset

Fault channel for the detection of very short thick places or neps. Thick place which is shorter than 1 cm. OEM = Original Equipment Manufacturer The USTER® QUANTUM 3 installation is delivered to the customer by the machine manufacturer who acts as OEM partner for Uster Technologies. Detection of periodic faults at multiple wave length. Set length over which a clearing feature is evaluated. See software release Resetting an electronic circuit to a preset initial state.

Retrofit

On a winding machine, an already existing clearer installation is exchanged by a new USTER® QUANTUM 3 installation.

Scatter plot

Graphic representation of the detected events within a classification matrix. One event = 1 point.

S-channel

Fault channel for the detection of short thick places.

Sensitivity

Set %-value for the determination of the clearing limit.

Smart limits Software pack

Software release Spinning cop Splice Splice check T-channel Tailored classes Thick place, long Thick place, short

A proposed starting point for clearing limits. A package consists of various software parts (see also Software release). Released USTER® QUANTUM 3 software package consisting of a CCU and an iMH software version. Is indicated by Rel and five digits (X.XX.XX, e.g. 1.01.05) and shows the level of development of the installed software. See bobbin Yarn t based on the interlacing of the two yarn ends. Checking of a splice with regard to its mass or diameter increase and length in the splice channel of the installation. Fault channel for the detection of thin places. Classes can be selected by customers. Faulty yarn mass increase which is at least than 8 cm. Faulty yarn mass increase which is between 1 and shorter than 8 cm long.

Thick place, very short

Faulty yarn mass increase (nep) which is shorter than 1 cm.

Thin place, short

Faulty thin yarn section

Upper yarn check

Vegetable Clearing

USTER® QUANTUM 3

Check the yarn drawn from the package during splice cycle. Prevent from ing two or more yarns from the package to the yarn from the bobbin (lower yarn). Separation of vegetable matter.

16.9

16

Appendix

Winding position Yarn body Yarn clearing Yarn fault Yarn fault channel Yarn fineness

Yarn measurement value Yarn t

16.10

Winding unit of a winding machine, which winds the yarn of several bobbins to a cone. The yarn body is defined as the nominal yarn with its tolerable, frequent yarn faults. The detection and removal of disturbing yarn faults. Faulty yarn section which is detected by the yarn clearing. Collective term for all thick and thin places. See fault channel. (Yarn count) System of units for yarn: Nm, Nec, New

Ratio: Length/mass

Tex

Ratio: Mass/length

Electrical signal, which is continuously determined from the yarn mass or the yarn diameter in the measuring field. ing of two yarn ends by a splice or knot.

USTER® QUANTUM 3

Appendix

16.4

16

International Systems of units

16.4.1 International system During the last decades, most countries have revised the laws referring to measurement determinations. The motivation for this was the introduction of an internationally-recognized system of measuring units which is known under the name of "Système International d'Unités" (abbreviation: SI) or Internationale System of Units. In the European Commuity (EC), the deadline for introducing the SIsystem was already reached at the end of 1977, and in Switzerland, this deadline ran until the end of 1982. Also in the East European countries, a forerunner to this SI-system, the MKSA-system was legally embodied quite early on, and in Eastern , for instance, even as early as 1958.

16.4.2 'SI' system Confusion in the system of units during the last decades has often led to quite considerable difficulties in science and technology, and more particularly in commerce. This resulted, even many years ago, in various forward-thinking scientists suggesting a reorganization of the system of units. An important foundation stone, in this respect, was laid by the Italian physicist Giorgi as far back as the year 1901. His suggestion led, in 1948, to the international recognition of the MKSA-system (meter-kilogramsecond-ampere). All physical units used in science and technology could be related to these four basic units. In the year 1960, at a general conference on weights and measures, the SI-system was officially accepted. The SI-system differs from the MKSA-system in that the four referred to fundamental units of meters, kilograms, seconds and amperes were extended by the Kelvin (temperature), the Mol (amount of substance) and the Candela (intensity of light) as further basic units. Although, according to present-day knowledge, every physical size which can be measured can be related to a combination of these 7 basic units, it is quite frequent to find that certain used combinations have their own name. For instance, in the SI-system, the force unit of kg • m/s² is allowed to be referred to as the "Newton" [N]. For work done, which in the SI-system has the unit kg • m/s² • m, the reference Newton-meter [Nm] or Joule [J] can be used. As the physical sizes, in some cases, extend over a quite wide range of figures, it is allowed that, for a decimal multiple or a part of a basic unit, derived units such as milli, deci, kilo, etc., can be applied. Table 16-1 shows the seven base units of the SI System of Units. All the additional units are derived from these 7 base units. Physical parameter

Unit

Abrevation

Length

Meter

m

Mass

Kilogram

kg

Time

Second

s

Electric current

Ampere

A

Temperature

Kelvin

K

Amount of substance

Mole

mole

Intensity of light

Candela

cd

USTER® QUANTUM 3

Table 16-1 Seven base units

16.11

16

Appendix

With the SI-system, there are two special properties which are to be given preference: •

In the SI-system, the derived units are coherent, i.e., all derived units are a combination of basic units in which only the numerical factor 1 is encountered.

•

The SI-system is characterized by 'freedom from contradiction', i.e., every physical size can only be described in one manner with the help of the basic units.

The units allowed and those which are obsolete when applying the SI-system for fiber, sliver, roving and yarn testing are summarized in the following table: Physical parameter

SI-units and other legally-allowed units

Conversion

Obsolete units

km, cm, mm

1 m = 1,099 yard

Inch, yard, mile

kg/m

ktex, tex (1 ktex = 1 g/m) (1tex = 1 g/km)

1 tex = 1000/Nm 1 tex = 590,5/Nec

Nm, Nec, New, den, grains/yd, etc.

kilogram

kg

g, mg, µg

1 kg = 2,204624 lbs

Grain (gr), ounce (oz), pound (lb)

Newton

N

mN, cN

1N = 0.102 kgf

kg, kg*, kgf, gf, lb, lbf

Newton/tex

N/tex

cN/tex

1 cN/tex = 0,9807 • Rkm

g/tex, Rkm, CSP

Newton • meter (Joule)

N•m

cN • cm

1 cN • cm = 0.9807 gf • cm 1 N • m = 0.09807 kgf • m

g • cm, kg • m

Base unit

Abbreviation

Derived units

meter

m

kilogram/meter

Mass

Force

Length Length-related mass

Tenacity

Work done

Table 16-2

Unfortunately the textile industry still uses obsolete unit systems. The following tables are conversion tables.

16.12

USTER® QUANTUM 3

Appendix

16

16.4.3 Conversion table for yarn count systems In the textile industry, it is often the case that in the same spinning mill both English and metric systems of count determination are used with fiber assemblies. The following table enables the conversion into one or the other of the count systems. The use of this table is illustrated based on an example: For a particular yarn the English cotton count Nec = 32 is known. The yarn count in tex is to be determined. One looks fist of all in the column "GIVEN" for the section Nec. In this section one moves downwards until one reaches tex in the "TO DETERMINE" column. Now one carries out the calculation referred to in this field. tex =

590.5 590.5 = = 18.45 Ne c 32

Metric

tex

dtex

den

grains yard

tex

1

dtex ⋅0.1

den ⋅ 0.111

grains 70.86 yard

dtex

tex ⋅ 10

1

den ⋅1.11

den

tex⋅ 9

dtex ⋅ 0.9

tex 70.68

μg inch

μg inch

Nm

Nec

Nel

New

Y.S.W.

μg inch 25.4

1'000 Nm

590.5 Ne c

1653.5 Ne l

885.8 Ne w

1937.7 Y.S.W.

grains ⋅ 708.6 yard

μg inch 2.54

10'000 Nm

5905.4 Ne c

16'535 Ne l

8858 Ne w

19'377 Y.S.W.

1


μg inch 2.82

9'000 Nm

5314.9 Ne c

14'882 Ne l

7972.3 Ne w

17'439 Y.S.W.

dtex 708.6

den 637.7

1

μg inch 1801.4

14.1 Nm

8.33 Nec

23.33 Nel

12.5 Ne w

27.34 Y.S.W.

tex ⋅ 25.4

dtex ⋅ 2.54

den ⋅ 2.82


1

25'400 Nm

15'000 Ne c

42'000 Nel

22'500 Ne w

49'218 Y.S.W.

Nm

1'000 tex

10'000 dtex

9'000 den

14.1 grains yard

25'400 μg inch

1

Nec ⋅ 1.693

Nel ⋅ 0.605

New ⋅1.13

Y.S.W. • 0.516

Nec

590.5 tex

5'905.4 dtex

5314.9 den

8.33 grains yard

15'000 μg inch

Nm 1.693

1

Nel 2 .8

Ne w 1 .5

Y.S.W. 3.28

Nel

1'653.5 tex

16'535 dtex

14'882 den

23.33 grains yard

42'000 μg inch

Nm 0.605

Nec ⋅ 2.8

1

New ⋅ 1.87

Y.S.W. 1.172

New

885.8 tex

8'858 dtex

7972.3 den

12.5 grains yard

22'500 μg inch

Nm 1.13

Nec ⋅ 1.5

Nel 1.87

1

Y.S.W. 2.187

Y.S.W.

1'937.7 tex

19'377 dtex

17'439 den

27.34 grains yard

49'218 μg inch

Nm 0.516

Nec ⋅ 3.28

Nel ⋅ 1.172

New ⋅ 2.187

1

grains yard

English

Metric

English

←TO DETERMINE

GIVEN →

Table 16-3

USTER® QUANTUM 3

16.13

16

Appendix

Explanation of the abbreviations dtex

=

Decitex

Nec

=

Cotton hank number

den

=

Denier

Nel

=

Linen lea number

μg/inch (approx)

=

Fiber count system (can be determined with Micronaire type instruments)

New

=

Worsted hank number

Nm

=

Metric count

Y.S.W.

=

Yorkshire skeins woollens

16.4.4 Conversion of English units into metric units The units referred to in this handbook are primarily metric units In order to be able to convert all the figures into English units, the more important conversions as used in the textile industry are provided here. Name of the unit

Length units

Area units

Mass units

Force units

Tenacity

Symbol

Metric unit

1 inch

in

2.54 cm

1 foot (= 12 in)

ft

0.3048 m

1 yard (= 3 ft)

yd

0.9144 m

1 mile

mile

1609.344 m

1 lea (120 yds), cotton

lea

109 m

1 hank (840 yds), cotton

hank

768 m

1 square inch

sq in

6.4516 cm

1 square foot

sq ft

929.030 cm

1 square yard

sq yd

0.836127 m

1 square mile

sq mile

2.58999 km

1 grain

gr

0.064799 g

1 ounce

oz

28.3495 g

1 pound

lb

0.453592 kg

1 gram-force

gf

0,0098 N

1 ounce-force

ozf

0.278014 N

1 pound-force (=16 ozf)

lbf

4.44822 N

1 kgf • Nec

0.579 cN / tex

1 kilogram-force • Nec 1 gram-force per denier

Pressure units

1 gf / den

2 2 2

2

8.838 cN /tex 2

6894.76 N/m

2

2

47.8803 N/m

2

1 pound-force per square inch (p.s.i)

lbf/in

1 pound-force per square foot

lbf/ft

Table 16-4

16.14

USTER® QUANTUM 3

Appendix

16.5

16

Bibliography

1.

Lawrence, C.,A., “Fundamentals of Spun Yarn Technology”, CRC Press LLC, 2003.

2.

Lord, P. R., “Handbook of Yarn Production: Technology, Science and Economics”, Woodhead Publishing Limited, 2005.

3.

Schindler C., ITMF COTTON CONTAMINATION SURVEY 2007, 29th International Cotton Conference, Proceedings, Bremen, April 2 - 5, 2008.

4.

Ajgaonkar, D.B.,”Principles of Knitting XXXIII”, The Indian Textile Journal,163-170, October 1975.

5.

ITMF COTTON CONTAMINATION SURVEY 2009

6.

The Textile Institute Textile and definitions 8th Edition”, Manara Printing Services, London, 1986.

7.

USTER® QUANTUM 3 Operational Handbook: “The yarn quality assurance system -Winding”, 316 052-10010, December 2010.

8.

USTER® QUANTUM 2 Application Handbook: “On-line quality management on winding machines”, V2.2, 304 000-89720, December 2008.

9.

USTER® TESTER 5 Application Handbook: “Laboratory system for the measurement of yarns, rovings and slivers”, V1.3, 410 106-04020, December 2008.

10.

USTER® News Bulletin No 47: “Origins of fabric defects – and ways to reduce them: Recommendations for Spinning Mills”, July 2010.

11.

USTER® News Bulletin No 45: “Think Quality: Opportunities to improve the quality in the textile supply chain”, July 2008.

12.

USTER® CLASSIMAT QUANTUM Application Handbook, “Classification of thick and thin places, classification of foreign fibers”, V1.1, 304 100-89720, May 2005.

13.

USTER® CLASSIMAT QUANTUM Application Manual, “Analysis of yarns by a sophisticated classifying system”, Se 620, May 2008.

14.

USTER® ZWEIGLE SPLICE TESTER 4 Application Report: “Determination of the strength and elongation of splices”, SE 633, February 2010.

15.

USTER® ZWEIGLE SPLICE TESTER 4 Application Handbook, “Determination of the strength and elongation of splices”, V1.0, 623 106-04020, October 2009.

16.

Behery H., Thomas, R.K.T., “Understanding the Short Staple Manufacturing Process and the Sources of its Yarn Faults”.

USTER® QUANTUM 3

16.15

16

16.16

Appendix

USTER® QUANTUM 3

Uster Technologies AG Sonnenbergstrasse 10 CH-8610 Uster / Switzerland Phone +41 43 366 36 36 Fax +41 43 366 36 37 www.uster.com Local sales and service organizations under: www.uster.com → USTER /Tools → Customer SW 461 040-10020 Printed in Switzerland © Copyright 2011 Uster Technologies AG

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