Designation:D3770–91StandardSpecificationforFlexibleCellularMaterials—High-ResiliencePolyurethaneFoam(HR)andCombustionModifiedHighResilience(CMHR)PolyurethaneFoam1ThisstandardisissuedunderthefixeddesignationD3770;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thisspecificationcoverstheminimumphysicalproper-tiesandotherrequirementsforhigh-resiliencepolyurethanefoam(HR)andcombustionmodifiedhighresiliencepolyure-thanefoams(CMHR).1.2Combustionmodifiedhighresiliencepolyurethanefoamsarehighresiliencefoamsthathavebeenmodifiedtomeetspecificflammabilityrequirements.1.3Thisspecificationincludesreferencestogovernmentregulationsforburningcharacteristicsofflexiblecellularmaterialsusedinspecificapplications(seeTable1).2.ReferencedDocuments2.1ASTMStandards:D3453SpecificationforFlexibleCellularMaterials—UrethaneforFurnitureandAutomotiveCushioning,Bed-ding,andSimilarApplications2D3574TestMethodsforFlexibleCellularMaterials—Slab,Bonded,andMoldedUrethaneFoams2D3675TestMethodforSurfaceFlammabilityofFlexibleCellularMaterialsUsingaRadiantHeatEnergySource22.2OtherDocuments:DOTMVSS3023DOCFF4–723CAL.TB1174CAL.TB1334NFPA2605BSI58526FAAPart25.853,Paragraph6,AppendixF3FAAOilBurnerTest33.Classification3.1Thisspecificationcoverstwogradesofflexiblehigh-resiliencepolyurethanefoammaterialthatmaybeselectedforuseaccordingtoload-bearingandotherminimumphysicalproperties(seeTable2).Generally,GradeHR-IisusedforfurnitureapplicationsandGradeHR-IIisusedforfurnitureapplicationsandmattresses.4.OrderingInformation4.1Anyproductrepresentedascomplyingwiththisspeci-ficationshallmeetalltherequirementslistedhereinforitsparticularclassification.4.2Ordersformaterialunderthisspecificationshallincludethefollowinginformation:4.2.1TypeIorIIofHRrequiredaslistedinthisspecifica-tion,4.2.2Gradenumberand...
