ASTM_D_4031_-_07_2012.pdf

Designation:D403107(Reapproved 2012)Standard Test Method forBulk Properties of Textured Yarns1This standard is issued under the fixed designation D4031;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 the changein length of a tensioned skein of textured yarn due to change incrimp characteristics brought about by exposure to wet or dryheat.The change in length,depending on procedure,is ameasure of skein shrinkage,crimp contraction,bulk shrinkage,or crimp recovery.1.2 This test method applies to crimped,continuous multi-filament yarns ranging from 1.7 to 88.9 tex(15 to 800 denier).1.3 Three conditions are provided for crimp developmentmediums,and loading routines are provided to be used on theyarn skeins to allow determination of yarn bulk by severaldifferent procedures.1.4 The values stated in either SI units or inch-pound unitsare to be regarded as standard.Within the text,the inch-poundunits are shown in parentheses.The values stated in eachsystem are not exact equivalent;therefore,each system shall beused independently of the other.Combining values from thetwo systems may result in nonconformance with the specifi-cation.1.5 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ASTM Standards:2D123 Terminology Relating to TextilesD1059 Test Method for Yarn Number Based on Short-Length Specimens(Withdrawn 2010)3D1776 Practice for Conditioning and Testing TextilesD1907 Test Method for Linear Density of Yarn(Yarn Num-ber)by the Skein MethodD2258 Practice for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:bulkshrinkage,crimp contraction,crimp development medium,crimp recovery,skein shrinkage.3.2 For all other terms are related to textiles,refer toTerminology D123.4.Summary of Test Method4.1 A skein of yarn of a prescribed size(linear density)issubjected to a crimp development medium using a specifiedloading routine.As the crimp is developed or shrinkage occursin the yarn,the skein changes in length.The lengths of theskein under specified tension forces are used to calculate thevalue of bulk shrinkage,crimp contraction,skein shrinkage,orcrimp recovery.4.2 The test method offers three options for loading routineof the yarn skeins.Loading routines consist of using low-tension forces(light loads of 0.04 to 0.98 mN/tex(0.5 to 11mgf/den)that extend without removing crimp,and high-tension forces(heavy loads of 8.8 mN/tex(100 mgf/den)thatremove crimp without elongating the yarn.A list of weights tobe used is given in Table 1.Weight option combinations aredetailed in Table 2.5.Significance and Use5.1 The values obtained by this test method should not beused to predict similar properties in fabricated structures exceptin narrow well-defined comparisons,such as 16.7 tex(150-denier)polyester from the same feed yarn merge and texturedon the same machine type.Attempts to relate yarn performanceto fabric performance might result in poor correlations unlessother factors affecting bulk such as yarn shrinkage and fabricfinishing are eliminated.5.2 Elapsed time between processing and testing has amarked effect on the results of this test especially during thefirst 72 h.Therefore,specimens should only be compared if1This 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 July 1,2012.Published August 2012.Originallyapproved in 1981.Last previous edition approved in 2007 as D4031 07.DOI:10.1520/D4031-07R12.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 tested after the same elapsed time.This effect is caused bystress decay which is known to be minimal beyond the seventhday and after which time the sample remains relatively stable.Comparisons are preferably made after the seventh day.5.3 In the case of yarns having a linear density near theupper limit of the skein size directed in Table 3,an error isintroduced when rounding off t