ASTM_D_2084_-_11_2016.pdf

Designation:D208411(Reapproved 2016)Standard Test Method forRubber PropertyVulcanization Using Oscillating Disk CureMeter1This standard is issued under the fixed designation D2084;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 This test method covers the use of the oscillating diskcure meter for determining selected vulcanization characteris-tics of vulcanizable rubber compounds.1.2 ISO 3417 is very similar to this test method.It has minortechnical differences that are not considered to be significant.1.3 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.4 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-ingD3185 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 OilD3187 Test Methods for RubberEvaluation of NBR(Acrylonitrile-Butadiene Rubber)D3190 Test Method for RubberEvaluation of ChloropreneRubber(CR)D4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries2.2 ISO Standard:ISO 3417 RubberMeasurement of Vulcanization Charac-teristics With the Oscillating Disk Rheometer33.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 The following measurements may be taken from thetorque versus time curve(see Fig.1).3.1.2 cure rate indexmeasure of rate of vulcanizationbased on the difference between optimum vulcanization andincipient scorch time.3.1.3 peak cure ratemeasure of rate of vulcanizationexpressed as the maximum slope of the torque versus timecurve.3.1.4 maximum,plateau,or highest torquemeasure ofstiffness or shear modulus of the fully vulcanized test specimenat the vulcanization temperature.3.1.5 minimum torquemeasure of the stiffness of theunvulcanized test specimen taken at the lowest point of thecurve.3.1.6 time to incipient cure(scorch time)measure of thetime at which vulcanization begins.3.1.7 time to a percentage of full curemeasure of curebased on the time to develop some percentage of the highesttorque or difference in torque from the minimum.3.1.8 torquefor an oscillating shear cure meter,the valuemeasured by a torque transducer at the peak strain amplitude ofthe oscillating cycle.3.1.9 optimum cure timemeasure of the time required toreach a percentage of full cure that corresponds to a desiredlevel of a property of the cured compound.3.1.9.1 DiscussionThe time to reach 90%cure corre-sponds to a maximum in tensile strength for some rubbercompounds.This does not apply in all cases.1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand Rubber-like Materials and is the direct responsibility of Subcommittee D11.12on Processability Tests.Current edition approved Nov.1,2016.Published December 2016.Originallyapproved in 1971.Last previous edition approved in 2011 as D2084 11.DOI:10.1520/D2084-11R16.2For 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,25 W.43rd St.,4thFloor,New York,NY 10036.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Summary of Test Method4.1 A test specimen of vulcanizable rubber compound isinserted into the cure meter test cavity and after a closureaction is contained in a sealed cavity under positive pressure.The cavity is maintained at some elevated vulcanizationtemperature.The rubber totally surrounds a biconical disk afterthe dies are closed(see Fig.2).The disk is oscillated througha small rotational amplitude(1 or 3)and this action exerts ashear strain on the test specimen.The force required to oscillateor rotate the disk to maximum amplitude is continuouslyrecorded as a function of time,with the force being propor-tional to the shear modulus(stiffness)of the test specimen atthe test temperature.This stiffness initially decreases as itwarms up;then it increases due to vulcanization.The test iscompleted when the recorded torque either rises to an equilib-rium or maximum value,or when a predetermined time h