ASTM_D_575_-_91_2012.pdf

Designation:D57591(Reapproved 2012)Standard Test Methods forRubber Properties in Compression1This standard is issued under the fixed designation D575;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 These test methods cover two test procedures for deter-mining the compression-deflection characteristics of rubbercompounds other than those usually classified as hard rubberand sponge rubber.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:2D3183 Practice for RubberPreparation of Pieces for TestPurposes from ProductsD3767 Practice for RubberMeasurement of DimensionsD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesE4 Practices for Force Verification of Testing Machines3.Summary of Test Methods3.1 These tests constitute one kind of compression stiffnessmeasurement.Deflection is the change in thickness of thespecimen upon application of a compressive force.The twodifferent procedures are as follows:3.1.1 Test Method ACompression Test of SpecifiedDeflectionA compression test in which the force required tocause a specified deflection is determined.3.1.2 Test Method BCompression Test at SpecifiedForceA compression test in which the specified mass orcompressive force is placed on the specimen and the resultingdeflection is measured and recorded.4.Significance and Use4.1 These test methods are useful in comparing stiffness ofrubber materials in compression.They can be used by rubbertechnologists to aid in development of materials for compres-sive applications.5.Apparatus5.1 Compression Testing MachineA compression testingmachine conforming to the requirements of Practices E4,andhaving a rate of head travel of 12 6 3 mm/m(0.5 6 0.1in./min),may be used for either type of test.Any other typemachine that will meet these requirements may be used.Forexample,a platform scale equipped with a yoke over theplatform and a hand-operated screw to apply the force willserve if it will conform to the requirements prescribed foraccuracy and rate of travel.Compression tests at specifiedforces may be performed on any machine that applies minorand major forces gently,without impact,or by placing speci-fied masses gently on the specimen.The machine shall beequipped to permit measurement of the deflection caused bythe increase from minor force to major force.5.2 Deflection GageThe deflection shall be read on a gageof dial type graduated in hundredths of millimetres(or thou-sands of an inch).5.3 MicrometerThe thickness of the specimen shall bemeasured in accordance with Test Method A of PracticeD3767.6.Test Specimens6.1 The test may be performed either on rubber products oron standard test specimens,as specified.NOTE1Comparable results are obtained only when tests are made onspecimens of exactly the same size and shape,tested to the samepercentage deflection,or tested under the same force.6.2 Standard test specimens shall be 28.6 6 0.1 mm(1.1296 0.005 in.)in diameter(650 mm2(1.000 in.2)in area)and1These test methods are under the jurisdiction of ASTM Committee D11 onRubber and are the direct responsibility of Subcommittee D11.10 on PhysicalTesting.Current edition approved Jan.1,2012.Published March 2012.Originallyapproved in 1940.Last previous edition approved in 2007 as D575 91(2007).DOI:10.1520/D0575-91R12.2For 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 12.5 6 0.5 mm(0.49 6 0.02 in.)in thickness,from which allmolded surface layers have been removed.7.Preparation of Specimens7.1 The standard test specimens may be prepared as fol-lows:A slab approximately 13 mm(0.51 in.)in thickness maybe cut from a product or may be molded from the samecompound used in the preparation of the product and ground onboth sides to obtain smooth parallel surfaces and the standardthickness of 12.5 6 0.5 mm(0.49 6 0.02 in.).The grindingshall be carried out as prescribed in Section 5 of PracticeD3183 and shall be done without overheating the rubber.Thespecimens may then be cut from t