Designation:D4946−89(Reapproved2012)StandardTestMethodforBlockingResistanceofArchitecturalPaints1ThisstandardisissuedunderthefixeddesignationD4946;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversanacceleratedprocedureforevaluatingtheface-to-faceblockingresistanceoftradessalespaints.ThisisnottobeconfusedwithblockingresistanceTestMethodD3003,whichisconcernedwithblockingofindustrialcoatingsonmetalsubstrates,norwithTestMethodD2793whichisconcernedspecificallywithwoodproductfinishesandreportsresultsonasatisfactoryornotsatisfactorybasis,ratherthanbythedegreeofblockingtendencyasinthistestmethod.1.2ThevaluesstatedintheSIunitsofmeasurementaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D16TerminologyforPaint,RelatedCoatings,Materials,andApplicationsD2793TestMethodforBlockResistanceofOrganicCoat-ingsonWoodPanelSubstratesD3003TestMethodforPressureMottlingandBlockingResistanceofOrganicCoatingsonMetalSubstrates3.Terminology3.1Definitions:3.1.1blocking,n—theundesirablestickingtogetheroftwopaintedsurfaceswhenpressedtogetherorplacedincontactwitheachotherforanextendedperiodoftime,asreferencedinTerminologyD16.4.SummaryofTestMethod4.1Driedpaintfilmsareplacedface-to-faceandapressureofabout127g/cm2(1.8psi)isapplied.Thesepaintfilmsareputintoanovenfor30mintomakethetestmorestringent.Aftercooling,theblockedpanelsarepeeledapart.ThedegreeofblockingisratedsubjectivelyfortackorsealusingaseriesofstandarddescriptivetermscorrespondingtonumericalASTMvalue...
