ASTM_D_2210_-_13.pdf

Designation:D221013Standard Test Method forGrain Crack and Extension of Leather by the Mullen Test1This standard is issued under the fixed designation D2210;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.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 resis-tance of leather to grain cracking and for measuring theextension of the leather.It is limited to light leathers such asshoe uppers,garment,gloves,and upholstery.This test methoddoes not apply to wet blue.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:2D1610 Practice for Conditioning Leather and Leather Prod-ucts for TestingD1813 Test Method for Measuring Thickness of LeatherTest Specimens3.Terminology3.1 Definitions:3.1.1 extensionthe amount of stretch of leather over thediaphragm under pressure.3.1.2 grain crackingthe appearance of cracks on thesurface of the leather as the leather is extended over adiaphragm under pressure to form a sphere.4.Significance and Use4.1 The test method is designed to measure the forcerequired to crack the grain of leather by steady hydraulicpressure on a diaphragm of definite diameter applied to theflesh side of the specimen to form a sphere.The cracking of thegrain is a result of failure under elongation or stretch.Theelongation or stretch of the leather can be measured at differentloads or at the failure of the grain to determine if the stressleather will withstand under lasting conditions.Cuts,scratches,and other defects will cause considerable variation in theresults by concentration of the applied force to the weak points.This test method is excellent for manufacturing control,speci-fication acceptance,and service evaluation in the lastingproperty of leather.This test method may not apply when theconditions of the test employed differ widely from thosespecified in the test method.5.Apparatus5.1 Testing Machine,3as shown in Fig.1.The machine shallbe hand-or power-driven.The machine shall hold the speci-men firmly,without slippage,between two annular,plane,unpolished(matte)surfaces that may have fine,spiral toolmarks not over 0.010 in.(0.25 mm)in depth.5.2 Upper Clamping SurfaceThe upper clamping surface(clamping ring)shall have a circular opening 1.240 6 0.010 in.(31.50 6 0.25 mm)in diameter and shall be connected to theclamping mechanism through a swivel joint to ensure an evenclamping pressure.5.3 Lower Clamping SurfaceThe lower clamping surface(diaphragm plate)shall be 0.219 6 0.003 in.(5.56 6 0.08 mm)thick and have an opening of 1.240 6 0.01 in.(31.50 6 0.52mm)in diameter.The circular edges of the openings that comein contact with the specimen and the rubber diaphragm shall berounded to a radius of not over 0.025 in.(0.64 mm)to preventany cutting action.During the test,the circular edges of the1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.03 on Footwear.This testmethod was developed in cooperation with the American Leather Chemists Assn.(Standard Method E58 1965).Current edition approved Nov.1,2013.Published November 2013.Originallyapproved in 1963 as D2210 63T.Last previous edition approved in 2012 asD2210 00(2012).DOI:10.1520/D2210-13.2For 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.3The sole source of supply of the apparatus known to the committee at this timeis B.F.Perkins,939 Chicopee St.,Chicopee,MA 01013-2797,(413)536-1311.Ifyou are aware of alternative suppliers,please provide this information to ASTMHeadquarters.Your comments will receive careful consideration at a meeting of theresponsible technical committee,which you may attend.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 openings in the two clamping plates shall be substantiallyconcentric with no overlapping of any point.5.4 Diaphragm,of rubber,0.034 6 0.002 in.(0.86 6 0.05mm)thick,clamped under the lower clamping plate so that,before the diaphragm is stretched by pressure underneath it,thecenter of its upper