1、Designation:D220900(Reapproved 2015)Standard Test Method forTensile Strength of Leather1This standard is issued under the fixed designation D2209;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 p
2、arentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This test method covers the determination of the loadrequired to
3、rupture a leather test specimen having a12-in.(12.7-mm)width.The load to rupture divided by the originalunstretched cross-sectional area gives the tensile strength.Itmay be used for all types of leather that are smooth and firmenough to permit accurate thickness measurements.This testmethod does not
4、 apply to wet blue.1.2 The values stated in inch-pound units are to be regardedas the standard.The values given in parentheses are forinformation only.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 st
5、andard 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:2D1517 Terminology Relating to LeatherD1610 Practice for Conditioning Leather and Leather Prod-ucts for TestingD1813 Test Meth
6、od for Measuring Thickness of LeatherTest SpecimensD2211 Test Method for Elongation of Leather3.Terminology3.1 For definitions of leather terms used in this standardrefer to Terminology D1517.4.Summary of Test Method4.1 The width and thickness are measured in the center ofthe narrow area of the leat
7、her specimen.The specimen isclamped in the testing machine as described in 9.3.The forcerequired to rupture the leather at a jaw separation of 10 6 2in./min.is measured.The tensile strength is calculated in psi orin kPa by dividing the force by the area of the original crosssection of its narrow sec
8、tion.The percent elongation at ruptureis also measured.5.Significance and Use5.1 The tensile strength test gives a reliable indication of thequality of the leather.Improperly lubricated and partiallydegraded leathers give low values for tensile strength.Theorientation of the specimen in relation to
9、the backbone and thelocation of the specimen on the hide influence the resultssignificantly.This test method is excellent for development,control,specification acceptance,and service evaluation ofleather.This test method may not apply when the conditions oftest employed differ widely from those spec
10、ified in the testmethod.6.Apparatus6.1 Testing Machine,Power-Driven The applied loadshall be indicated on a dial,scale,or chart.The load indicatorshall record or indicate the maximum load at the time ofrupture of the specimen.The machine shall be equipped with aset of grips for clamping the specimen
11、s.The faces of the gripsshould be knurled or otherwise roughened to prevent slippingof the specimen.The gripping surfaces shall be at least 1 by 112in.(25.4 by 38 mm).The grips shall be mounted with thelonger dimension perpendicular to the direction of the appli-cation of the load.The speed of the p
12、ower-activated grip shallbe uniform speed of 10 6 2 in./min(254 6 50 mm/min)whenrunning free.The error of the machine up to a load of 50 lbf(222 N)shall not exceed 2%;at loads of more than 50 lbf theerror shall not exceed 1%.6.2 Thickness GageAdead-mass type of thickness gage asdescribed in Test Met
13、hod D1813.6.3 Steel Scale,graduated to read in 0.02 in.(0.5 mm).6.4 Steel Die,to cut test specimens designed as shown inFig.1.6.5 Cutting Block,which shall consist of a flat hardwoodsupport upon which is placed a flat,smooth sheet of firmmaterial that will not injure the cutting edge of the die.1Thi
14、s test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.07 on Physical Properties.Thistest method was developed in cooperation with the American Leather ChemistsAssn.(Standard Method E15 1965).Current edition approved May 1,2015.Pu
15、blished July 2015.Originally approvedin 1963.Last previous edition approved in 2010 as D2209 00(2010).DOI:10.1520/D2209-00R15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refe
16、r 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 7.Test Specimen7.1 The specimen shall be dumbbell in shape,cut from thetest unit of leather by means of a die as shown in Fig.1.Thedirection of the long dimension in relation to the backboneshall be noted.8.Conditioning8.1 All specimens shall be conditioned in accordance withPractice D1610.Conditioning other than that prescribed
