Designation:D4620−02(Reapproved2012)StandardTestMethodforEvaluatingtheEffectiveSurfaceAreaofZincOxideinRubber1ThisstandardisissuedunderthefixeddesignationD4620;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodspecifiesthestandardmaterials,mix-ingprocedure,andtestmethodforrankingzinc-oxidesamplesaccordingtotheirspecificsurfaceareainastandardtestformulabasedonchloroprenerubber(CR).1.2TherankingisbasedonthecuretimeofthestandardCRformulation.1.3Theaccuratesurfaceareacannotbedeterminedbythistestmethod,sincefactorsotherthansurfaceareamayinfluencethecuretimestosomeextent(forexampleacidity,heavymetaltraces,etc.).1.4ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D1646TestMethodsforRubber—Viscosity,StressRelaxation,andPre-VulcanizationCharacteristics(MooneyViscometer)D2084TestMethodforRubberProperty—VulcanizationUsingOscillatingDiskCureMeterD3190TestMethodforRubber—EvaluationofChloropreneRubber(CR)D5289TestMethodforRubberProperty—VulcanizationUsingRotorlessCureMeters3.SummaryofTestMethod3.1Separateformulationsofachloroprene-rubbercom-poundarepreparedcontaining3-methyl-thiazolidine-thione-2andothercompoundingmaterials.Oneormoreformulation(s)containtheexperimentalorcandidatezinc-oxidegrade(s)tobeevaluatedandtheotherstandardformulation(s)oneormorezinc-oxidegrade(s)ofknownsurfacearea.3.2Thecuretimes(t890)oftheformulationsaremeasuredasspecifiedinTestMethodD2084orD5289andusedtoranktheunknownzinc-oxidewithrespecttothe...
