Designation:D3768−16StandardTestMethodforMicrocellularUrethanes—FlexuralRecovery1ThisstandardisissuedunderthefixeddesignationD3768;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoverstheprocedureandapparatusformeasuringtheflexuralrecoveryofmicrocellularurethanes.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.NOTE1—ThereisnoknownISOequivalenttothisstandard.2.ReferencedDocuments2.1ASTMStandards:2D883TerminologyRelatingtoPlasticsD3040PracticeforPreparingPrecisionStatementsforStan-dardsRelatedtoRubberandRubberTesting(Withdrawn1987)3D3489TestMethodsforMicrocellularUrethaneMaterialsE691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethod3.Terminology3.1Fordefinitionsoftermsusedinthistestmethodandassociatedwithplasticsissues,refertoterminologycontainedinTerminologyD883.3.2ThefollowingdefinitionisfromTestMethodsD3489:3.2.1microcellularurethane,n—anelastomericmaterialmadebytheinteractionofapolyolandanorganicisocyanate,havingcelldiametersintherangefrom0.0001to0.001mm,withaminimumdensityof160kg/m3(10lb/ft3).4.SignificanceandUse4.1Thistestmethodisusedtoindicatetheabilityofamaterialtorecoveraftera180°bendarounda12.7-mm(0.5-in.)diametermandrelatroomtemperature.4.2Beforeproceedingwiththistestmethod,referenceshallbemadetoanyspecificationforthematerialbeingtested.Anytestspecimenpreparation,conditioning,ordimensions,orcombinationthereof,andtestingparameterscoveredinthematerialsspecificationshalltakeprecedenceoverthosemen-tionedinthesetestmethods.Iftherearenomaterialspecifica...
