1、Designation:D7269/D7269M20Standard Test Methods forTensile Testing of Aramid Yarns1This standard is issued under the fixed designation D7269/D7269M;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
2、 parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 These test methods cover the tensile testing of aramidyarns,cords twisted from such yarns,and fabrics woven fromsuch cords.The yarn or cord may be w
3、ound on cones,tubes,bobbins,spools,or beams;may be woven into fabric;or maybe in some other form.The methods include testing procedureonly and include no specifications or tolerances.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stat
4、ed ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.3 This standard includes the following test methods:SectionBreaking Force11Breaking Tenacity12Breaking Tou
5、ghness17Elongation at Break13Force at Specified Elongation(FASE)14Linear Density10Modulus15Stress at Break12Work-to-Break161.4 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-pr
6、iate 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 theDevelopm
7、ent of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D76 Specification for Tensile Testing Machines for TextilesD123 Terminology Relating to TextilesD1776 Practice for Cond
8、itioning and Testing TextilesD1907 Test Method for Linear Density of Yarn(Yarn Num-ber)by the Skein MethodD2258 Practice for Sampling Yarn for TestingD3800 Test Method for Density of High-Modulus FibersD4848 Terminology Related to Force,Deformation andRelated Properties of TextilesD6587 Test Method
9、for Yarn Number Using AutomaticTesterE23 Test Methods for Notched Bar Impact Testing of Me-tallic Materials3.Terminology3.1 Definitions:3.1.1 slippage,nwith tensile testing,insufficient quality ofclamping,resulting in movement of the test material throughthe total clamping surface.This can be visual
10、ized by themovement of markers at the clamp exit,or by sudden changesin the strain-modulus curves(1st derivative of the strain-stresscurve).3.2 The following terms are relevant to this standard:aramid,breaking force,breaking tenacity,breaking toughness,chord modulus,elongation,force at specified elo
11、ngation(FASE),industrial yarn,initial modulus,moisture equilibriumfor testing,standard atmosphere for testing textiles,work-to-break.3.3 For definitions of terms related to force and deformationin textiles,refer to Terminology D4848.3.4 For definitions of other terms related to textiles,refer toTerm
12、inology D123.1These test methods are under the jurisdiction of ASTM Committee D13 onTextiles and are the direct responsibility of Subcommittee D13.19 on IndustrialFibers and Metallic Reinforcements.Current edition approved Feb.1,2020.Published February 2020.Originallyapproved in 2006.Last previous e
13、dition approved in 2017 as D7269/D7269M17.DOI:10.1520/D7269_D7269M-20.2For 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 webs
14、ite.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 Intern
15、ational Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.4.Summary of Test Method4.1 These test methods are used to determine the tensileproperties of aramid yarns or cords.4.2 Aconditioned or oven-dried specimen of aramid yarn orc
16、ord is clamped in a tensile testing machine and then stretchedor loaded until broken.Breaking force,elongation,and force atspecified elongation(FASE)are determined directly.Modulusand work-to-break are calculated from the force-elongationcurve.The output of a constant-rate-of-extension(CRE)tensiletesting machine can be connected with electronic recording andcomputing equipment,which may be programmed to calculateand print the test results of tensile properties of interest.5.Significance and Use5