ASTM_D_6774_-_22.pdf

Designation:D677422Standard Test Method forCrimp and Shrinkage Properties for Textured Yarns Using aDynamic Textured Yarn Tester1This standard is issued under the fixed designation D6774;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 determination of crimpcontraction,residual fiber shrinkage and their variability of alltypes of filament yarns(partially oriented yarn(POY),fullyoriented yarn(FOY),flat yarns,textured and bulked continu-ous filament(BCF)carpet yarns)using an automated tester.NOTE1For another method of testing crimp in textured yarns,refer toTest Method D4031.1.1.1 This method may also be used for non-textured yarns.1.2 This test method is limited to crimped,multi-filamentyarns ranging from 22.0 dtex to 890 dtex(15 denier to 800denier)and for BCF yarns from 890 dtex to 4200 dtex(800denier to 3800 denier).1.3 The values stated in SI units are to be regarded asstandard.Inch-pound units in parentheses after SI units areprovided for information only and are not considered standard.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD2258 Practice for Sampling Yarn for TestingD4031 Test Method for Bulk Properties of Textured YarnsD4849 Terminology Related to Yarns and Fibers3.Terminology3.1 For definitions of textile terms in this test method,referto Terminology D4849.For other textile terms used in this testmethod,refer to Terminology D123.4.Summary of Test Method4.1 The specimen passes through a pretension device toremove crimp.The specimen then passes,at a constant speed,around an input roller,to a calibrated sensor which maintains aspecific tension.4.1.1 Subsequently,the specimen passes through a heatingelement,at a low tension,where the specimen shrinks andagain is crimped.4.1.2 The crimped specimen then goes to an intermediateroll,at a low tension.4.1.3 The specimen then travels to a second sensor,whichmaintains a tension equal to the pretension applied,to removedeveloped crimp.4.2 Residual fiber shrinkage,crimp developed,and maxi-mum total contraction are calculated by the computer softwareusing speeds of the input,intermediate and output rolls.5.Significance and Use5.1 Test Method D6774,for determining maximum totalcontraction,crimp,and residual fiber shrinkage in texturedfilament yarns is suitable for acceptance testing of commercialshipments.5.1.1 If there are differences of practical significance be-tween reported test results for two laboratories(or more),comparative tests should be performed to determine if there isa statistical bias between them,using competent statisticalassistance.As a minimum,use the samples for such a com-parative tests that are as homogeneous as possible,drawn fromthe same lot of material as the samples that resulted in disparateresults during initial testing and randomly assigned in equalnumbers to each laboratory.The test results from the labora-tories involved should be compared using a statistical test forunpaired data,a probability level chosen prior to the testing1This 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 March 1,2022.Published March 2022.Originallyapproved in 2002.Last previous edition approved in 2010 as D6774 02(2010)which was withdrawn January 2019 and reinstated March 2022.DOI:10.1520/D6774-22.2For 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1series.If a bias is found,either its cause must be found andcorrected,or fut