Designation:D4708−12StandardPracticeforPreparationofUniformFreeFilmsofOrganicCoatings1ThisstandardisissuedunderthefixeddesignationD4708;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thispracticecoversthepreparationoffreefilmsoforganiccoatingsforuseindeterminingthephysicalpropertiesofthecoatings.Proceduresaregivenforpreparingfreefilmsonthreealternativesubstrates.ThesesubstratesaretreatedFEP(fluorinatedethylene-propylene)sheet,siliconecoatedpaper,andhalosilanecoatedglassplates.1.2ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D823PracticesforProducingFilmsofUniformThicknessofPaint,Varnish,andRelatedProductsonTestPanelsD1005TestMethodforMeasurementofDry-FilmThick-nessofOrganicCoatingsUsingMicrometersD1653TestMethodsforWaterVaporTransmissionofOr-ganicCoatingFilmsD2370TestMethodforTensilePropertiesofOrganicCoat-ingsE96/E96MTestMethodsforWaterVaporTransmissionofMaterials3.SummaryofTestMethod3.1Freefilmsarepreparedbydepositingauniformwetcoatingofthetestmaterialonareleasesubstrate.Theappliedfilmsaredriedorbaked,cutintoappropriatesizefortheintendedphysicalpropertytest,andthenstrippedfromthereleasesubstrate.4.SignificanceandUse4.1Freefilmsarerequiredforconductingteststoevaluatephysicalandmechanicalpropertiessuchastensileandelon-gation(TestMethodsD2370andE96/E96M),moisturevaporpermeability(TestMethodsD1653),andotherphysicalprop-ertiesoforganiccoatingswherethesubstratemayinterferewiththedetermination.5.ApparatusandMaterials5.1...
