ASTM_D_434_-_95.pdf

Designation:D 434 95An American National StandardStandard Test Method forResistance to Slippage of Yarns in Woven Fabrics Using aStandard Seam1This standard is issued under the fixed designation D 434;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(e)indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1.Scope1.1 This test method covers the determination of the resis-tance to slippage of filling yarns over warp yarns,or warpyarns over filling yarns,using a standard seam.1.2 The test method is not intended for upholstery fabrics.2.Referenced Documents2.1 ASTM Standards:D 76 Specification for Tensile Testing Machines for Tex-tiles2D 123 Terminology Relating to Textiles2D 1682 Test Methods for Breaking Load and Elongation ofTextile Fabrics2D 1776 Practice for Conditioning Textiles for Testing2D 1905 Test Method for Dimensional Changes in Launder-ing of Woven or Knitted Textiles3D 2721 Test Method for Effects of Drycleaning on Perma-nence of Durable Water-Repellent Finish22.2Federal Standard:751a Stitch Seam and Stitching43.Terminology3.1 Definitions:3.1.1 resistance to yarn slippage n.the force required toseparate the parts of a standard seam assembly by a specifiedamount.3.2 For definitions of other textile terms used in this method,refer to Terminology D 123.4.Summary of Test Method4.1 The load-elongation curve of the fabric is superimposedover a load-elongation curve of the same fabric with a standardseam sewn parallel to the yarns being tested.Resistance to yarnslippage is reported as the load at which a slippage of aspecified size is seen.5.Significance and Use5.1 This method is considered satisfactory for acceptancetesting because the method has been used extensively in thetrade for acceptance testing.In case of disagreement arisingfrom differences in values reported by the purchaser and theseller when using this test method for acceptance testing,thestatistical bias,if any,between the laboratory of the purchaserand the laboratory of the seller should be determined with eachcomparison being based on testing specimens randomly drawnfrom one sample of material of the type being evaluated.5.2 This test method is used as an indication of the tendencyof yarns to slip at a seam.Such slippage results in garmentfailure at a seam,which is not readily repairable by reseaming.5.3 The force at which the load-elongation curve of thefabric with the seam is a predetermined distance greater thanthe load-elongation curve of the fabric without a seam isreported as the pounds-force per inch(newtons per metre)resistance to yarn slippage.Generally,a14-in.(6.4-mm)separation is used,but for some fabrics a smaller opening ispreferred.If desired,the force to affect complete separationmay be obtained by continuing the load-elongation curve untilcomplete separation is obtained.A 1-lbf(4.45-N)compensa-tion is deducted to allow for elongation of the seam.5.4 Currently interlaboratory tests are being made to deter-mine accuracy and precision.This method can also be used toevaluate the correlation between the CRE and CRI testingmachines.6.Apparatus6.1 Tensile Testing Machine(CRT)(Preferred)CRT(pen-dulum)type with an autographic recorder conforming to therequirements of Method D 76.The machine shall be equippedwith clamps having frontjaws 1 in.(25 mm)in width andbackjaws 2 in.(50 mm)or more in width,except as otherwiseprovided.The clamps shall be set in 3 in.(8.0 mm)apart.Thespeed of the lower clamp shall be 12 612in.(300 6 10mm)/min.NOTE1In comparing results with those from another laboratory,both1This test method is under the jurisdiction of ASTM Committee D-13 onTextiles,and is the direct responsibility of Subcommittee D13.59 on Fabric TestMethods,General.Current edition approved April 15,1995.Published August 1995.Originallypublished as D 434 36 T.Last previous edition D 434 75.2Annual Book of ASTM Standards,Vols 07.01.3DiscontinuedSee 1977 Annual Book of ASTM Standards,Part 32.4Available from Standardization Documents Order Desk,Bldg.4 Section D,700Robbins Ave.,Philadelphia,PA 19111-5094,Attn:NPODS.1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.laboratories should use the same type of tensile testing machine,or haveestablished the relationship between test results obtained using a CRTmachine and those obtained using a CRE machine when testing fabrics ofthe type being evaluated.6.2 Tensile Testing Machine(CRE)A constant-rate-of-extension type machine equivalent to the CRT machine speci-fied in 6.1.6.3 Dividers,one pair.6.4 Metal Rule,graduated in132-in.or 1-mm subdivisions.6.5 Metal Clamp,auxiliary,6-oz(170 g),at least 4 in.(102mm)in width.7.Number of Specimens7.1 For preliminary testing,two specimens are required,onewith the lo