ASTM_D_1646_-_19a.pdf

Designation:D164619aStandard 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.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 SourcesSampling1These test methods are under the jurisdiction of ASTM Committee D11 onRubber and Rubber-like Materials and are the direct responsibility of SubcommitteeD11.12 on Processability Tests.Current edition approved Nov.1,2019.Published November 2019.Originallyapproved in 1959.Last previous edition approved in 2019 as D1646 19.DOI:10.1520/D1646-19A.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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 D4483 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