ASTM_D_6076_-_08_2013.pdf

Designation:D607608(Reapproved 2013)Standard Test Method forShrinkage Temperature of Leather1This standard is issued under the fixed designation D6076;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 Department of Defense.1.Scope1.1 This test method covers the determination of the shrink-age temperature of all types of leather.The heating medium iswater when the shrinkage temperature is at or below 98C.Theheating medium is a glycerine-water solution when the shrink-age temperature is above 98C.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.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:2D1517 Terminology Relating to Leather3.Terminology3.1 DefinitionsFor definitions of general leather termsused in this test method,refer to Terminology D1517.3.2 Definitions of Terms Specific to This Standard:3.2.1 shrinkto contract or become smaller.3.2.2 shrinkagethe temperature at which noticeableshrinkage occurs when a leather specimen is gradually heatedin an aqueous medium.4.Summary of Test Method4.1 A leather specimen is thoroughly soaked in the aqueousmedium that will be used to heat the specimen for this testmethod.This specimen is then fastened between two clamps(one fixed and one movable)and immersed in the aqueousmedium.The aqueous medium is gradually heated until thespecified temperature is reached without shrinkage or untilshrinkage is indicated by a deflection of the dial needle whichis attached to the movable clamp.5.Significance and Use5.1 This test method is designed to determine the tempera-ture at which a thoroughly wetted leather specimen experiencesshrinkage.In this test method,shrinkage occurs as a result ofhydrothermal denaturation of the collagen protein moleculeswhich make up the fiber structure of the leather.The shrinkagetemperature of leather is influenced by many different factors,most of which appear to affect the number and nature ofcrosslinking interactions between adjacent polypeptide chainsof the collagen protein molecules.The value of the shrinkagetemperature of leather is commonly used as an indicator of thetype of tannage or the degree of tannage,or both,of thatparticular leather(especially for the more hydrothermallystable tannages such as chrome tannage).6.Apparatus6.1 Stand,for supporting the testing equipment.6.2 Indicating Device,either of the two devices listed asfollows:6.2.1 Theis Shrinkage Meter Diala dial indicator having aface divided into 360 to 380,with one revolution of the dialhand corresponding to 12.7 mm(0.5 in.)of specimenmovement,and with leeway for four revolutions of the dialhand.36.2.2 AGD(American Gage Design)Dial IndicatorAmechanical device capable of registering on a scale a reading1This 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 from Federal Test Method Standard No.311,Method7011.1,in cooperation with the U.S.Defense Personnel Support Center,Directorateof Clothing and Textiles,Philadelphia,PA and the U.S.Army Natick Research,Development and Engineering Center,Natick,MA.Current edition approved May 1,2013.Published July 2013.Originally approvedin 1997.Last previous edition approved in 2008 as D6076-08.DOI:10.1520/D6076-08R13.2For 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.3A shrinkage meter apparatus setup meeting these specific requirements wasformerly available from theArthur H.Thomas Co.,Philadelphia,PA.The minimumnumber of apparatus setups required for an order makes the cost of new apparatusof this type prohibitive.Used apparatus of this type may still be available fromtanneries or laboratories that have gone out of business or from used equipmentdealers.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 of the shrinkage or swelling movement of the specimen in aratio of at least 25 units of dial movement(or greater)to 1 unitof specimen movement,and shall accurately detect by move-ment of the dial needle the point at which shrinkage begins.The indicator shall have a spindle capable of attachment to thespecimen and to the adjustable weight asse