ASTM_D_2591_-_07_2020.pdf

Designation:D259107(Reapproved 2020)Standard Test Method forLinear Density of Elastomeric Yarns(Short LengthSpecimens)1This standard is issued under the fixed designation D2591;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 the lineardensity of short lengths of“as produced”elastomeric yarnsmade from rubber,spandex or other elastomers.NOTE1For the determination of linear density of elastomeric yarnsusing skeins,refer to Test Method D6717.1.2 This test method is not applicable to covered,wrapped,or core-spun yarns,or yarns spun from elastomeric staple,orelastomeric yarns removed from fabrics.1.3 This test method is applicable to elastomeric yarnshaving a range of 40 to 3200 dtex(36 to 2900 denier).1.4 The values stated in either SI units or U.S.Customaryunits are to be regarded separately as standard.Within the testthe US Customary units are in parentheses.The values stated ineach system are not exact equivalents;therefore,each systemshall be used independently of the other.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 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 TestingD6717 Test Method for Linear Density of Elastomeric Yarns(Skein Specimens)D4849 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:denier,elastomeric yarn,linear density,tex.3.2 For all other terminology related to textiles,refer toTerminology D123.4.Summary of Test Method4.1 A pre-relaxed specimen is fastened in verticallymounted apparatus under a specified tension.Aspecified lengthis cut from the specimen and weighed,and the linear densitycalculated.5.Significance and Use5.1 This test method is considered satisfactory for accep-tance testing of commercial shipments because current esti-mates of between-laboratory precision are acceptable and themethod is used extensively in the trade for acceptance testing.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 samples for such comparativetests that are as homogeneous as possible,drawn from the samelot of material as the samples that resulted in disparate resultsduring initial testing,and randomly assigned in equal numbersto each laboratory.The test results from the laboratoriesinvolved should be compared using a statistical test forunpaired data,at a probability level chosen prior to the testingseries.If bias is found,either its cause must be found andcorrected,or future test results for that material must beadjusted in consideration of the known bias.5.2 Linear density of elastomeric yarns is used in somecalculations for tensile and elastic properties.5.3 The test method is based on elastomeric yarns in lthe“as-produced”condition,but may be used for treated elasto-meric yarns provided the treatment is specified.The method1This 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 Feb.1,2020.Published February 2020.Originallyapproved in 1967.Last previous edition approved in 2013 as D2591 07(2013).DOI:10.1520/D2591-07R20.2For 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.does not cover the removal of finish for