monitoring and automation in spinning mills

R. Furter October 2008 SE 627

APPLICATION REPORT QUALITY MANAGEMENT Monitoring and automation in spinning mills

THE STANDARD FROM FIBER TO FABRIC


Copyright 2008 by Uster Technologies AG All rights reserved. No part of this publication may be reproduced, stored in a re-trieval system, translated or transmitted in any form or by any means, electroni-cally, mechanically, photocopying, recording or otherwise, without the prior permis-sion in writing of the copyright owner. veronesi\TT\Schulung_Dokumente\QualityManagement\SE_SD-627_Monitoring and automation\SE_627.doc

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Contents

1 Introduction ................................................................................ 4

2 Clearers on winding machines ................................................. 4

3 Clearers on OE rotor spinning machines ................................ 5

4 Classifying Systems .................................................................. 5

5 Conclusions................................................................................ 6

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1 Introduction The year 2008 is a milestone in the history of Uster Technologies. This company has started the first development of yarn clearers for winding ma-chines in the year 1960. The year 2008 marks 3 events:

• We have installed 4 million yarn clearers on winding machines • We have installed 2 million yarn clearers on OE rotor spinning machines • We have installed 3000 Classifying Systems

Therefore, there are good reasons to look back over 5 decades and de-scribe the pioneering role which Uster Technologies played in this particular domain. It is also an opportunity to look forward and to describe some ex-pectations among textile specialists for the next five years with respect to quality and quality management. 2 Clearers on winding machines The change from manual to automatic processes in the textile industry has often boosted new developments in textile electronics because automatic machines require various sensors to control individual functions. In the early Sixties the first automatic winding machines were introduced in the market. An automatic winding machine had to replace disturbing thick places automatically by a knot. This had to be done with a mechanical knot-ter on the machine. The “sensor” which had to detect the thick places was the “Uster Slub Catcher”. This was a small mechanical apparatus with an adjustable slot. The slot width was set in such a way that it came to a yarn break at the arrival of a disturbing thick place. This kind of sensor did not fulfil the requirements of an automatic winding machine. Therefore, Uster Technologies started the development of an electronic yarn clearer. This electronic system played an important role on the winding machines in the past 48 years. It represents the last monitoring system in the spinning process where remaining disturbing yarn faults can be elimi-nated and replaced by a splice. It also represents a filter where off-quality bobbins can automatically be separated from the yarn batch. The USTER® QUANTUM is the 6th generation of yarn clearers. The clearer for winding machines is a sophisticated sensor which is able to eliminate disturbing thick places, thin places, foreign fibers and separate bobbins which do not fulfil the conditions with respect to evenness, imperfections, hairiness, count deviations, etc. Fig. 1 shows an electronic yarn clearer on a winding machine.



Fig. 1 Electronic yarn clearer installed on the winding machine

3 Clearers on OE rotor spinning machines In 1967 the first OE rotor spinning machine was demonstrated to the textile community. In 1982 the OE rotor spinning machine was automated, i.e. yarn breaks caused by remaining disturbing faults could automatically be repaired by a piecer. The automation of this machine has boosted the utili-zation of a sensor on this machine in order to detect disturbing yarn faults and to eliminate such faults. The replacement of the yarn faults by a piecer was taken over by a robot. With the invention of the robot the OE rotor spinning machine became the first fully-automatic spinning machine. The USTER® QUANTUM for OE rotor spinning machines is the forth gen-eration of clearers for this machine. This clearer is capable to detect and eliminate disturbing thick places, thin places, foreign fibers, and it can also determine the quality level of the yarn package with respect to evenness, imperfections, hairiness, count deviations, etc. 4 Classifying Systems The correct settings of the yarn clearers of the first generation was rather complex because it was unknown what kind of yarn faults had to be elimi-nated and how many cuts per 100 km had to be executed. Therefore, an analyzing system was developed which served for a previous analysis of the number and size of disturbing yarn faults. In 1968 Uster Technologies has introduced this classifying system, the USTER® CLASSIMAT, with which disturbing thick places could be analyzed in detail. With this system the thick places could be determined which had to be cut by the winding machine.



With the classified faults and the “clearing curve” the head of the winding room could also determine the number of cuts required per 100 kilometers to eliminate the most disturbing faults, and, therefore, the efficiency of the machine.

Fig. 2 USTER® CLASSIMAT GRADES of 1970 Fig.2 shows how the disturbing faults could be categorized in 16 thick place classes. These grades were used to determine what kind of thick places had to be eliminated by the clearer and which faults could remain in the yarn to keep the efficiency of the machine on a high level. 5 Conclusions The history of textile electronics is a fascinating example how improve-ments in measuring technology can be converted in higher quality and higher productivity. The better quality of yarns did not only influence the productivity of spinning machinery but also the subsequent processes such as weaving and knitting. The spinning technology of today does not yet allow the production of fault-free yarns. Most of the spinning mills have installed monitoring systems either on the OE rotor or winding machines to eliminate such faults.




A spinning mill of average size has between 20’000 and 40’000 production positions. Due to mechanical problems or contamination of the production positions we have to expect outlier bobbins or packages every day which do not fulfill the expectations with respect to count, count variation, even-ness, imperfections, hairiness, strength, elongation, etc. Since one single bobbin which is out of tolerance can destroy a considerable amount of a textile fabric, it will be an important task of the textile electronics industry in

e next five years to recognize such bobbins and to eliminate them from

system on the OE rotor spinning machine in the mid Eighties a onitoring system could be placed on all the last machines in the spinning rocess.

ththe spinning process. Uster Technologies was a pioneer with the development of the electronic clearing system in the early Sixties and with the introduction of an analyzing system, the USTER® CLASSIMAT, a few years later. With the installation of a clearer mp

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Uster Technologies AG Wilstrasse 11

H-8610 Uster / Switzerland C Phone +41 43 366 36 36

ax +41 43 366 36 37 F www.uster.com [email protected]

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monitoring and automation in spinning mills

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