ASTM_D_623_-_07_2014.pdf

Designation:D62307(Reapproved 2014)Standard Test Methods forRubber PropertyHeat Generation and Flexing Fatigue InCompression1This standard is issued under the fixed designation D623;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.1.Scope1.1 These test methods may be used to compare the fatiguecharacteristics and rate of heat generation of different rubbervulcanizates when they are subjected to dynamic compressivestrains.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:2D395 Test Methods for Rubber PropertyCompression SetD1349 Practice for RubberStandard Conditions for Test-ingD3182 Practice for RubberMaterials,Equipment,and Pro-cedures for Mixing Standard Compounds and PreparingStandard Vulcanized SheetsD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries2.2 ASTM Adjuncts:Goodrich Flexometer Anvil Drawings33.Summary of Test Method3.1 The test consists of subjecting a specimen of rubber ofdefinite size and shape to rapidly oscillating compressivestresses under controlled conditions.Although heat is gener-ated by the imposed oscillating stress,the more convenientparameter,the temperature rise,is measured.The measuredtemperature rise is one of two types:(1)to an equilibriumtemperature or(2)the rise in a fixed time period.Additionalmeasured performance properties are the degree of permanentset or other specimen dimensional changes,or both,and forcertain test conditions,the time required for a fatigue failure byinternal rupture or blow out.3.2 Two test methods are covered,using the followingdifferent types of apparatus:3.2.1 Test Method AGoodrich Flexometer.3.2.2 Test Method BFirestone Flexometer.4.Significance and Use4.1 Because of wide variations in service conditions,nocorrelation between these accelerated tests and service perfor-mance is given or implied.However,the test methods yielddata that can be used to estimate relative service quality ofdifferent compounds.They are often applicable to research anddevelopment studies.5.Preparation of Sample5.1 The sample may consist of any vulcanized rubbercompound except those generally classed as hard rubber,provided it is of sufficient size to permit preparation of the testspecimen required for the test method to be employed.Thesample may be prepared from a compound mixed experimen-tally in the laboratory or taken from process duringmanufacture,or it may be cut from a finished article ofcommerce.5.2 If prepared in the laboratory,the procedure shouldpreferably be essentially as specified in Practice D3182,exceptthat when vulcanization is required,the sample should prefer-ably be molded in block form of sufficient size to permitcutting of the required test specimens rather than in the form ofthe standard test slab.5.2.1 The direct molding of the specimen for Test MethodAis allowed(see 9.4)but may not yield results identical tospecimens cut from a molded block.Care must be taken inpreparation on the raw stock for direct molding of specimens.1These test methods are under the jurisdiction of ASTM Committee D11 onRubber and are the direct responsibility of Subcommittee D11.15 on DegradationTests.Current edition approved May 1,2014.Published May 2014.Originallyapproved in 1941.Last previous edition approved in 2007 as D623 07.DOI:10.1520/D0623-07R14.2For 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.3Available from ASTM International Headquarters.Order Adjunct No.ADJD0623.Original adjunct produced in 1939.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.3 Samples from commercial articles shall consist of apiece slightly larger than the required test specimen and shallsubsequently be cut or buffed to size.5.4 Comparison of results shall be made only betweenspecimens of identical size and shape.TESTMETHODAGOODRICHFLEXOMETER46.Nature of Test6.1 In this test method,which uses the GoodrichFlexometer,a definite compressive load is applied to a testspecimen through a lever system having high inertia,whileimposing on the specimen an additional high-frequency cycliccompression of definite amplitude.The increase in temperatureat the base of the