【英文标准名称】:StandardPracticeforEstimatingCriticalSurfaceTensions
【原文标准名称】:临界表面张力的估算的标准办法
【标准号】:ASTMD7541-2009
【标准状态】:现行
【国别】:
【发布日期】:2009
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:D01.23
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:
【英文主题词】:criticalsurfacetension;dewetting;surfacecontamination;wettability;wetting
【摘要】:Knowledgeofthecriticalsurfacetensionofsubstrates,primersandothercoatingsisusefulforexplainingorpredictingwettabilitybypaintsandothercoatingsappliedtothosesurrfaces.Surfaceswithlowcriticalsurfacetensionsusuallyarepronetosufferdefectssuchascrawling,pictureframing,crateringandlossofadhesionwhenpainted.Loworirregularvalues,orboth,oftenareindicativeofcontaminationthatcouldreduceadhesion.Surfaceswithhighcriticalsurfacetensionsareeasytowetandusuallyprovideanexcellentplatformforpainting.Theswab,markingpenanddraw-downtestsallsimulatetheapplicationofafilmTheswabandmarkingpentechniquesaresimpleandrapidandareparticularlyusefulfortestinginthefieldoroncurved,irregularorporoussurfaceswherecontactanglescannotbemeasured.Thedroptestdoesnotworkwellonsuchsurfacesandthedraw-downmethodrequiresaflatspecimenthatisrelativelylarge.Theestimationofcriticalsurfacetensionhasbeenusefulincharacterizingsurfacesbeforeandaftercleaningprocessessuchaspowerwashesandsolventwipesinordertoevaluatetheefficiencyofthecleaning.Oneormoreofthesetechniquescouldbethebasisofago/no-goqualitycontroltestwhereifacertainliquidwets,thesurfaceisacceptableforpainting,butifthatliquidretractsandcrawls,thesurfaceisnotacceptable.Anothergo/nogotestispossiblewherethetestliquidisapaintandthesurfaceisasubstrate,primerorbasecoat.Aformofthistesthasbeenusedforcoatingsforplastics.1.1Thispracticecoversproceduresforestimatingvaluesofthecriticalsurfacetensionofsurfacesbyobservingthewettinganddewettingofaseriesofliquids(usuallyorganicsolvents)appliedtothesurfaceinquestion.1.2Anothertechnique,measurementofthecontactangles,x03B8;,ofaseriesoftestliquidsandplottingcosx03B8;versussurfacetension(Zismanplots),providesdatathatallowthedeterminationofmoreexactvaluesforcriticalsurfacetension.1.3ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:
【国际标准分类号】:25_220_01
【页数】:3P.;A4
【正文语种】: