ASTM_D_1646_-_07_2012.pdf

Designation:D164607(Reapproved 2012)Standard Test Methods forRubberViscosity,Stress Relaxation,and Pre-VulcanizationCharacteristics(Mooney Viscometer)1This standard is issued under the fixed designation D1646;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 procedures for measuring aproperty called Mooney viscosity.Mooney viscosity is definedas the shearing torque resisting rotation of a cylindrical metaldisk(or rotor)embedded in rubber within a cylindrical cavity.The dimensions of the shearing disk viscometer,testtemperatures,and procedures for determining Mooney viscos-ity are defined in these test methods.1.2 When disk rotation is abruptly stopped,the torque orstress on the rotor decreases at some rate depending on therubber being tested and the temperature of the test.This iscalled“stress relaxation”and these test methods describe a testmethod for measuring this relaxation.NOTE1Viscosity as used in these test methods is not a true viscosityand should be interpreted to mean Mooney viscosity,a measure ofshearing torque averaged over a range of shearing rates.Stress relaxationis also a function of the test configuration and for these test methods theresults are unique to the Mooney viscometer.1.3 When compounded rubber is placed in the Mooneyviscometer at a temperature at which vulcanization may occur,the vulcanization reaction produces an increase in torque.These test methods include procedures for measuring the initialrate of rubber vulcanization.1.4 ISO 289 Parts 1 and 2 also describes the determinationof Mooney viscosity and pre-vulcanization characteristics.Inaddition to a few insignificant differences there are majortechnical differences between ISO 289 and this test method inthat ISO 289 does not provide for sample preparation on a mill,while this test method allows milling sample preparation insome cases prior to running a Mooney viscosity test.This canresult in different viscosity values for some rubbers.1.5 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.6 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:2D1349 Practice for RubberStandard Conditions for Test-ingD1418 PracticeforRubberandRubberLaticesNomenclatureD1485 Practice for Rubber from Natural SourcesSampling and Sample PreparationD3182 Practice for RubberMaterials,Equipment,and Pro-cedures for Mixing Standard Compounds and PreparingStandard Vulcanized SheetsD3185 Test Methods for RubberEvaluation of SBR(Styrene-Butadiene Rubber)Including Mixtures With OilD3186 Test Methods for RubberEvaluation of SBR(Styrene-Butadiene Rubber)Mixed With Carbon Black orCarbon Black and OilD3896 Practice for Rubber From Synthetic SourcesSamplingD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries2.2 ISO Standard:3ISO 289 Rubber,UnvulcanizedDeterminations Using theShearing Disk Viscometer,Part 1 Determination of Mooney Viscosity,andPart 2 Determination of Prevulcanization Characteristics.3.Terminology3.1 Definitions of Terms Specific to This Standard:1These test methods are under the jurisdiction of ASTM Committee D11 onRubber and are the direct responsibility of Subcommittee D11.12 on ProcessabilityTests.Current edition approved May 1,2012.Published May 2012.Originallyapproved in 1959.Last previous edition approved in 2007 as D1646 07.DOI:10.1520/D1646-07R12.2For 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 American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.1 Mooney viscosity,nmeasure of the viscosity of arubber or rubber compound determined in a Mooney shearingdisk viscometer;viscosity is indicated by the torque required torotate a disk embedded in a rubber specimen and enclosed inthe die cavity under specified conditions.3.1.2 pre-vulcanization characteristics,nfor a vulcaniz-able compound,a measure of the time to the incipientvulcanization and the rate of cure during the early stages ofvulcanization.3.1.3 stress relaxation,nresponse of a raw or com-poun