Designation:D3768−22StandardTestMethodforMicrocellularUrethanes—FlexuralRecovery1ThisstandardisissuedunderthefixeddesignationD3768;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoverstheprocedureandapparatusformeasuringtheflexuralrecoveryofmicrocellularurethanes.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.NOTE1—ThereisnoknownISOequivalenttothisstandard.1.4Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D883TerminologyRelatingtoPlasticsD3040PracticeforPreparingPrecisionStatementsforStan-dardsRelatedtoRubberandRubberTesting(Withdrawn1987)3D3489TestMethodsforMicrocellularUrethaneMaterialsE456TerminologyRelatingtoQualityandStatisticsE691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethodE2935PracticeforEvaluatingEquivalenceofTwoTestingProcesses3.Terminology3.1TermsusedinthisstandardaredefinedinaccordancewithTerminologyD883,unlessotherwisespecified.Fortermsrelatingtoprecisionandbiasandassociatedissues,thetermsusedinthisstandardaredefinedinaccordancewithTerminol-ogyE456.3.2ThefollowingdefinitionisfromTestMethodsD3489:3.2.1microcellularurethane,n—anelastomericmaterialmadebytheinteractionofapolyolandanorganicisocyanate,havingcelldiametersintherangefrom0.0001to0.001mm,withaminimum...
