ASTM_D_7744_-_D_7744M_-_11.pdf

Designation:D7744/D7744M11Standard Test Methods forTensile Testing of High Performance Polyethylene Tapes1This standard is issued under the fixed designation D7744/D7744M;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 The test method covers the tensile testing of highperformance polyethylene tapes.The method includes testingprocedure only and includes 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 stated 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 Strength(Force)11Breaking Tenacity12Breaking Toughness17Elongation at Break13Force at Specified Elongation(FASE)14Linear Density10Modulus15Work-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-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D76 Specification for Tensile Testing Machines for TextilesD123 Terminology Relating to TextilesD1776 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 TestingD4848 Terminology Related to Force,Deformation andRelated Properties of TextilesD5947 Test Methods for Physical Dimensions of SolidPlastics SpecimensE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions:3.1.1 high-performance polyethylene,na polyethyleneyarn or tape with a tenacity at break of minimally 1000 mN/tex11 gpd.3.1.2 tape,nin high performance end-uses,a flat,highly-oriented strip of polymer material.3.2 Definitions:For definitions of terms related to force anddeformation in textiles,refer to Terminology D4848.3.3 The following terms are relevant to this standard:breaking force,breaking strength,breaking tenacity,breakingtoughness,modulus,force-extension curve,force-elongationcurve,elongation,force at specified elongation(FASE),tensilestrength,and work-to-break.3.4 For definitions of other terms related to textiles,refer toTerminology D123.4.Summary of Test Method4.1 A conditioned polyethylene tape is clamped in a con-stant rate of extension tensile testing machine(CRE)and thenstretched or loaded until broken.4.2 Breaking force,elongation,and force at specified elon-gation(FASE)are determined directly.Modulus and work-to-break are calculated from the force-elongation curve.5.Significance and Use5.1 The levels of tensile properties obtained when testinghigh performance polyethylene tapes are dependent on the ageand history of the specimen and on the specific conditions usedduring the test.Among these conditions are rate of stretching,type of clamps,gauge length of specimen,temperature andhumidity of the atmosphere,rate of airflow across thespecimen,and temperature and moisture content of the speci-men.Testing conditions accordingly are specified precisely toobtain reproducible test results on a specific sample.1This test method is under the jurisdiction ofASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.19 on Industrial Fibers andMetallic Reinforcements.Current edition approved July 15,2011.Published September 2011.DOI:10.1520/D7744_D7744M11.2For 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 States1 5.2 Breaking strength is used in engineering calculationswhen designing various types of products.When needed tocompare intrinsic strength characteristics tapes of differentsizes or different types of tape,breaking tenacity is very usefulbecause,for a given type of tape,breaking force is approxi-mately proportional to linear density.5.3 Elongation of tape is taken into consideration in thedesign and engineering of reinforced products because of itseffect on uniformity of the finished product and its dimensionalstability during service.5.4 The FASE is used to monitor changes in characteristicsof the material during the various stages involved in theprocessing.5.5 Modulus is a measure of the resistance of tape toexten