classimat.doc

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USTER CLASSIMAT: The appearance of a fault in the nished product, i.e. a woven or knitted fabric, is largelydetermined by its size. A yarn fault classication according to cross-section and length is thereforethe basis for the assessment of yarn faults.!T"# classimat is used for thedetection and classication of faults in theyarn. $e can also cut the yarn faults, but this is notdone for production point

of view.HISTORY: The !T"# %&A!!'(AT ) consisted of an analog computer and was sold in)*+ for therst time. The installation soon became the standard for thetetile industry. &arge knitters andweavers introduced the %&A!!'(AT valuesto the yarn suppliers with the intention to specifythe classes in which theywould no longer accept faults. (any spinning mills used the%&A!!'(AT forsetting the clearing curve and for checking the clearing with spot checks onthecleared yarn. The !T"# %&A!!'(AT ) was capable of counting faults in)+ thick place classes.Thick places were registered when the mass increasewith respect to the yarn meanvalue reached )/. 0or tetile specialists who

had been using the !T"#%&A!!'(AT for yarn analyses, the !T"#%&A!!'(AT 1#A2"! were introduced already in)*+*. These images of yarnfaults were representative of the )+ fault classes. 3n the one hand,thesegrades made it easier for spinners to decide which faults had to beeliminated. 3n theother hand, they served as a common basis foragreements between spinners andweavers4knitters.

The !T"# %&A!!'(AT 5 was a digital computer that was introduced to themarket in)*6. The system was capable of classifying yarn faults in threeadditional thick place classesand four thin place classes, because thegeneration of the !T"# %&A!!'(AT ) could no longermeet the customers

requirements. The additional classes were called E, F, G, H1, H2, I1 and I2 0urthermore, it



was possible to print out the results of the !T"# %&A!!'(AT 5.The !T"#%&A!!'(AT7 , nally, came on the market in )**8. 't was the rst testing unit that was based on a standard personalcomputer. Again, the system was further etended to meet the needs of plyyarn producers as well. This re9uired the introduction of 8 additional thickplace classes between 6; and )/, which were called A, <, % and

2. 'n addition, another + thin place classes, T<), T%), T2), T<5, T%5 and T25, were introduced, because the tetile industry had become more andmore sensitive to thin places.!T"# %&A!!'(AT generations and their functions!%3=" 30 %&A!!'(AT:0rom a statistical point of view, it is di>cult to determine the fre9uency ofyarn faults by testing random samples. 0irstly, we are dealing with seldom-occurring events, which mean that a large amount of testing material isre9uired for a statistically reliable measurement result. !econdly, yarn faultsare not evenly distributed within a lot. 'f a yarn normally shows onedisturbing fault per bobbin, for eample, there will always be individual

bobbins with ), ; or even more disturbing faults. This means that thefaults are not normally distributed within a yarn lot and that the rules for thecalculation of the condence limits based on the normal

distribution are therefore not applicable. $ith the application of the centraltheorem of limits, we can get around this di>culty, because the theoremsays that the mean values of partial groups of a population are normallydistributed even if that population as a whole is not normally distributed. 't istherefore advisable to divide the test sample of a classication into at leastve partial samples of the same size ?e.g. ) km of yarn@. "ach partialsample is tested separately. The statistical evaluation is carried outautomatically by the !T"# %&A!!'(AT ABT(.



't is advisable to combine the sampling for a yarn classication with anotherlaboratory test. $ith a large range of products, you can use partial bobbinsof sorted yarns, which are usually tested in the laboratory anyway, eitherperiodically or after changes have been made at the ring spinning machine. These partial bobbins and, depending on the size of a test, full bobbins aswell, are to be stored in an air-conditioned location and are tested if enough

material ?) km for each partial sample@ is available. At least four partialsamples of ) km each are re9uired for a statistical evaluation with the!T"# %&A!!'(AT ABT( 0re9uency of tests: once a month!ample size: 8 to + km ?8 to + partial samples@!mall orders, which often run for a relatively short time, re9uire a diCerentway of sampling. =artial samples of ) km of yarn are taken directly from aspinning machine and then tested. A sample can consist of yarn from onemachine or from several machines with the same material. This samplingmethod is appropriate for yarn fault analyses as well. The sample size has to

be adDusted depending on the importance of a test or the available amountof material. 'f the !T"# %&A!!'(AT ABT( is operated online at anautomatic winder, there is a constant supply of material that usually ensuresa proper sample size. To improve there liability of the evaluations, the size ofpartial samples can be increased up to ; km. Eowever, it must beconsidered that a test has to be monitored whenever possible. T"!T'B1 %3B2'T'3B!: The optimum ambient conditions are provided in a closed room with astandard atmosphere, i.e. with a temperature of 5F G 5F% and a relativehumidity of +;/ G 5/. The standard atmosphere in tropical areas ?'!3 )7*@is dened as a temperature of 56F G 5F% and a relative humidity of +;/ G

5/.The classication system has to be protected from warm ehaust air andfast-moving air currents, and the measuring heads have to be protected fromdirt. The environment has to be kept as clean as possible to preventunnecessary faulty measurements.



CLASSIMAT



!hort Thick =laces: &ong Thick =laces:

Fault Groups:

nacceptable faults A8, <8, %8, 28, %7, 27, 25(aDor faults A7, <7, %5, 2), ", 0, 1, E5, '), '5(inor faults A5, <5, A), <), %), E)

Fault Type:



Beps A7!hort thick place A), A5, A7, A8, <), <5, <7, <8, %)%5, %7, %8, 2), 25, 27, 28&ong thick place 0, 1! pinners double " Thin place E), E5&ong thin place '), '5

Reasons Chart:

A8 #ing front zone dirty, 0ly, $aste in trumpetA7 Beps, 0luC, 0oreign matter, 2irty drafting zoneA5 <ad condition of carding, <low room, Trash in yarnA) <ad condition of carding, <low room, Trash in yarn<8 !lub from ring department<7 0luC in ring traveller, unsuitable traveller and bad piecing<5 0ibre damage during process, spindle without aprons

<) 0ibre damage during process, spindle without aprons%8 0loating bres, 0ly,!lub%7 #ing piecing%5 <ad piecing in cans, !liver entanglement%) <ad piecing in cans,!liver entanglement28 (ore HuC in ring department27 (ore HuC in ring department25 !imple gauge problem,!pacer, Apron2) 0loating bres" 2ouble yarn0 <ad piecing in ring, simple and back process

1 <ad piecing in ring, simple and back processE) "ccentric bobbins of simple, ring, and eccentric spindlesE5 =oor handling of material') &ong thin places due to separation of sliver or roving prior to spinning'5 &ong thin places due to separation of sliver or roving prior to spinning

SUMMARY: The !T"# %&A!!'(AT ABT( is a comple testing system that oCers thecustomera multitude of applications and evaluation possibilities. 't can beused for productionmonitoring or as an analysis instrument for the clearersetting and for the preparation of supplyagreements or 9ualitycerticates.!T"# %&A!!'(AT if used in a proper way can increase the9uality of the product andalso the faulty process can be identied and eventhe fault producing part can be determinedwhich was not possible a fewyears ago.

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