ASTM_D_5169_-_98_2015.pdf

Designation:D516998(Reapproved 2015)Standard Test Method forShear Strength(Dynamic Method)of Hook and Loop TouchFasteners1This standard is issued under the fixed designation D5169;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 measures the shear strength of hookand loop touch(CRE)fasteners using a recording constant rateof extension tensile testing machine.1.2 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 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 TextilesD618 Practice for Conditioning Plastics for Testing3.Terminology3.1 Definitions:3.1.1 hook and loop fastenera touch fastener,comprisedof two flexible mating strips,the surface of one mating stripbeing covered with tiny,stiff protrusions shaped like hookswhich engage the other mating strip which is covered withpliable loops.3.1.1.1 DiscussionThis fastener comprises a non-adhesivemethod of joining two materials where ready adjustment andremoval is desirable and fastening is accomplished by pressingthe mating strips together and separation is accomplished bysimply peeling apart.Terms herein referring to hook and loopfastening systems shall be construed to include other types oftouch fasteners in which the fastening strength in the shearmode(that is,against forces applied in the plane of thefastener)substantially exceeds the fastening strength in thepeel mode(that is,against forces applied perpendicular to theplanes of the two components of the fastener).3.1.2 shear strength,nthe resistance to forces that cause,or tend to cause,two contiguous parts of a body to sliderelatively to each other in a direction parallel to their plane ofcontact.3.2 For definitions of other textile terms used in this testmethod,refer to Terminology D123.4.Summary of Test Method4.1 An area of hook surface is applied to an area of loopsurface with controlled engagement pressure.This combina-tion is subjected to a dynamic shear force acting parallel to thesurfaces of the specimens.5.Significance and Use5.1 This test method gives a measure of a key property ofhook and loop touch fasteners which is of interest to users ofsuch devices.This is a means of determining the resistance toseparation when forces are applied parallel to the plane of thefastener.5.2 In the case of a dispute arising from differences inreported test results when using this test method for acceptancetesting of commercial shipments,the purchaser and the sup-plier should conduct comparative tests to determine if there isa statistical bias between their laboratories.Competent statis-tical assistance is recommended for the investigation of bias.As a minimum,the two parties should take a group of testspecimens which are as homogenous as possible and which arefrom a lot of hook and loop of the type in question.The testspecimens should then be randomly assigned in equal numbersto each laboratory for testing.The average results from the twolaboratories should be compared using Students t-test and anacceptable probability level chosen by the two parties beforethe testing began.If a bias is found,either its cause must befound and corrected or the purchaser and the supplier mustagree to interpret future test results in the light of the knownbias.1This test method is under the jurisdiction ofASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.54 on Subassemblies.Current edition approved Feb.1,2015.Published April 2015.Originallyapproved in 1991.Last previous edition approved in 2010 as D5169 98(2010).DOI:10.1520/D5169-98R15.2For 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 6.Apparatus6.1 Rollerconsisting of a smooth steel surface,approxi-mately 434in.(21 mm)in diameter,214in.(57 mm)wide,andequipped with a handle,length 418in.(105 mm),for propellingthe roller back and forth without adding additional weight tothe specimen being rolled(see Fig.1).The weight of the roller(including the handle)is 11 lbs.614lb(4994 6 114 g).6.