ASTM_D_2594_-_D_2594M_-_21.pdf

Designation:D2594/D2594M21Standard Test Method forStretch Properties of Knitted Fabrics Having Low Power1This standard is issued under the fixed designation D2594/D2594M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the measurement of fabrics thatexhibit high stretch and good recovery from low tension.Fabric stretch is measured when a known load is applied.Fabric growth is evaluated after a known extension is appliedand subsequently removed.1.2 The procedures for fabric stretch and fabric growth canbe used together,or individually.1.3 While this test method can be used for a knit fabric,fabrics intended for support or other applications are betterevaluated using other test methods:D3107,D4964,D6614.1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system are not necessarily exact equivalents;therefore,toensure conformance with the standard,each system shall beused independently of the other,and values from the twosystems shall not be combined.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 TextilesD1776 Practice for Conditioning and Testing TextilesD2904 Practice for Interlaboratory Testing of a Textile TestMethod that Produces Normally Distributed Data(With-drawn 2008)3D2906 Practice for Statements on Precision and Bias forTextiles(Withdrawn 2008)3D3107 Test Methods for Stretch Properties of Fabrics Wo-ven from Stretch YarnsD4849 Terminology Related to Yarns and FibersD4850 Terminology Relating to Fabrics and Fabric TestMethodsD4964 Test Method for Tension and Elongation of ElasticFabrics(Constant-Rate-of-Extension Type Tensile TestingMachine)D6614 Test Method for Stretch Properties of Textile Fabrics CRE Method3.Terminology3.1 Definitions:3.1.1 For definition of textile terms used in this test method:bench marks,refer to Terminology D4849.3.1.2 For definitions of textile terms used in this testmethod:fabric growth;fabric stretch;low-power stretch andtension,refer to Terminology D4850.3.1.3 For definitions of other textile terms used in this testmethod,refer to Terminology D123.4.Summary of Test Method4.1 Fabric GrowthTension is applied to a looped fabricspecimen until it is extended to a specified elongation.The testspecimen is held in place for 2 h.The percent change in the testspecimen length is measured immediately after removal of thetension.The test specimen is then allowed one hour to recoverwithout tension.The percent change in test specimen length ismeasured again after this recovery period.4.2 Fabric StretchA specified tension is applied to andremoved from a looped fabric specimen for five cycles.On thefifth time tension is applied,the tension is held and the percentchange in the test specimen length is measured.1This test method is under the jurisdiction ofASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.59 on Fabric Test Methods,General.Current edition approved July 1,2021.Published August 2021.Originallyapproved in 1969.Last previous edition approved in 2020 as D2594 20.DOI:10.1520/D2594_D2594M-21.2For 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 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.15.Significance and Use5.1 Fabric stretch and fabric growth are useful in selectionof fabrics that are required to stretch,but also recover to theiroriginal shape.5.1.1 In apparel,fabric stretch can be caused by a variety offactors.Amomentary stress occurs when a