Designation:D4976−12aStandardSpecificationforPolyethylenePlasticsMoldingandExtrusionMaterials1ThisstandardisissuedunderthefixeddesignationD4976;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheDepartmentofDefense.INTRODUCTIONThisspecificationisnotintendedfortheselectionofmaterials,butonlyasameanstocalloutplasticmaterialstobeusedforthemanufactureofparts.Theselectionofthesematerialsistobemadebypersonnelwithexpertiseintheplasticsfieldwheretheenvironment,inherentpropertiesofthematerials,performanceoftheparts,partdesign,manufacturingprocess,andeconomicsareconsidered.Thisspecificationdoesnotspecifythesourceoftheresintobeusedforthefabricationofanygivenarticle.1.Scope*1.1Thisspecificationprovidesfortheidentificationofpolyethyleneplasticsmoldingandextrusionmaterialsinsuchamannerthatthesupplierandtheusercanagreeontheacceptabilityofdifferentcommerciallotsorshipments.Thetestsinvolvedinthisspecificationareintendedtoprovideinformationforidentifyingmaterialsinaccordancewiththegroups,classes,andgradescovered.Itisnotthefunctionofthisspecificationtoprovidespecificengineeringdatafordesignpurposes.1.2Otherrequirementsnecessarytoidentifyparticularchar-acteristicsimportanttospecializedapplicationsshallbeagreeduponbetweentheuserandthesupplier,byusingthesuffixesgiveninSection1.3.1.3Ethyleneplasticmaterials,beingthermoplastic,arereprocessableandrecyclable(seeNote1).Thisspecificationallowsfortheuseofthoseethyleneplasticmaterials,providedthatanyspecificrequirementsasgovernedbytheproducerandtheenduseraremet.NOTE1—SeeGuideD7209forinformationanddefinitionsrelatedtorecycledplastics.1.4ThevaluesstatedinSIunitsareregardedasstandard.1.5Thefollowingprecautionarycaveatpertainstothetestmethodportiononly,Section12,ofthisspecification.Thisstandardd...
