ASTM_D_6612_-_00_2011.pdf

Designation:D661200(Reapproved 2011)Standard Test Method forYarn Number and Yarn Number Variability Using AutomatedTester1This standard is issued under the fixed designation D6612;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the measurement of yarnnumber up to 4000 dtex(3600 denier)and related variabilityproperties of filament and spun yarns using an automated testerwith capability for measuring mass variability characteristics.1.2 Yarn number variability properties include percent den-sity spread(%DS),coefficient of variation(%CV),densityfrequency variation.NOTE1For determination of yarn number by use of reel and balance,refer to Test Method D1907.For another method of measuring variability(unevenness)in yarn,refer to Test Method D1425.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.Within the text,theinch-pound units are in parentheses.The values stated in eachsystem are not exact equivalents;therefore,each system shallbe used independently of the other.Combining values from thetwo systems may result in inaccuracies of results.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1425 Test Method for Unevenness of Textile Strands UsingCapacitance Testing EquipmentD1776 Practice for Conditioning and Testing TextilesD1907 Test Method for Linear Density of Yarn(Yarn Num-ber)by the Skein MethodD2258 Practice for Sampling Yarn for TestingD4849 Terminology Related to Yarns and Fibers3.Terminology3.1 For all terminology relating to D13.58,Yarns andFibers,refer to Terminology D4849.3.1.1 The following terms are relevant to this standard:cotton count,coefficient of variation,denier,linear density,tex,yarn number,yarn numbering system,bad/good test,densityfrequency variability,density spread.3.2 For all other textile terms used in this test method,seeTerminology D123.4.Summary of Test Method4.1 A specified length of yarn(specimen)is stripped auto-matically directly from the package,cut,and weighed.Theyarn number is calculated by interfaced computer,displayed ona monitor,and may be printed.The yarn number can bereported in tex,denier,or cotton count units.4.2 Simultaneously,by means of a capacitance cell,themass of the specimen is measured in subsections and frequencyof mass value crossovers are counted for calculation ofvariability properties:%DS,%CV,%BGT and%DFV.5.Significance and Use5.1 Test Method D6612 for yarn number and yarn numbervariability is satisfactory for acceptance of commercial ship-ments and is used in the trade.5.1.1 If there are differences of practical significance be-tween the reported test results for two or more laboratories,comparative tests should be performed by those laboratories todetermine if there is a statistical bias between them,usingcompetent statistical assistance.As a minimum,samples usedfor each comparative tests should be as homogeneous aspossible,drawn from the same lot of material as the samplesthat results in disparate results during initial testing,andrandomly assigned in equal numbers to each laboratory.Otherfabrics with established tests values are used for this purpose.The test results from the laboratories involved should becompared appropriate statistical analysis and a probabilitylevel chosen by the two parties before testing begins,at aprobability level chosen prior to the testing series.If a bias is1This test method is under the jurisdiction ofASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.58 on Yarns and Fibers.Current edition approved May 1,2011.Published July 2011.Originally approvedin 2000.Last previous edition approved in 2006 as D661200(2006)1.DOI:10.1520/D6612-00R11.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 found,either its cause must be found and corrected,or futuretest results adjusted in consideration of the known bias.5.1.2 The average results from the two laboratories shouldbe compared using appropriate statistical analysis and a prob-ability level chosen by the two parties before the testing isbegun.If a bias is found,either its cause must be found andcorrected or the purchaser and the supp