Designation:D6226−15StandardTestMethodforOpenCellContentofRigidCellularPlastics1ThisstandardisissuedunderthefixeddesignationD6226;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoverscellularplastics,whicharecomposedofmembranesorwallsofpolymerseparatingsmallcavitiesorcells.Thesecellsmaybeinterconnecting(opencell),non-connecting(closedcell),oranycombinationofthesetypes.Thistestmethoddeterminesnumericalvaluesforopencells.Itisaporositydetermination,measuringtheaccessiblecellularvolumeofamaterial.Theremainingvolumeisthatoccupiedbyclosedcellsandcellwalls.Sinceanyconvenientlysizedspecimenistypicallyobtainedbysomecuttingoperation,afractionoftheclosedcellswillbeopenedbyspecimenpreparationandwillbeincludedasopencells,(seeNote2).1.2Thistestmethodprovidesgoodaccuracyonpredomi-nantlyhighlyopen-celledmaterials.Bynotaccountingforclosedcellsthatwereopenedduringspecimenpreparation,theaccuracydecreasesastheclosedcellcontentincreasesandasthecellsizeincreases.1.3ThevaluesasstatedinSIunitsaretoberegardedasthestandard.Thevaluesinparenthesesaregivenforreferenceonly.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.NOTE1—ThistestmethodandISO4590usethesamebasicprinciplesbutaresignificantlydifferentinexperimentaldetail.NOTE2—TwoproceduresforcorrectingforcellsopenedduringspecimenpreparationaredescribedinAppendixX1.1.2.ReferencedDocuments2.1ASTMStandards:2D883TerminologyRelatingtoPlasticsD2842TestMethodforWaterAbsorptionofRigidCellularPlasticsD3576TestMethodforCellSizeofRigidCellularPlasticsE691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMe...