【英文标准名称】:StandardTestMethodforWaterAbsorptionofPlastics
【原文标准名称】:塑料吸水率的标准试验方法
【标准号】:ASTMD570-1998(2010)e1
【标准状态】:现行
【国别】:美国
【发布日期】:1998
【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】:D20.50
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:absorption;immersion;plastics;water;Immersion--plastics;Wateranalysis--plasticsprocessing
【摘要】:Thistestmethodforrateofwaterabsorptionhastwochieffunctions:first,asaguidetotheproportionofwaterabsorbedbyamaterialandconsequently,inthosecaseswheretherelationshipsbetweenmoistureandelectricalormechanicalproperties,dimensions,orappearancehavebeendetermined,asaguidetotheeffectsofexposuretowaterorhumidconditionsonsuchproperties;andsecond,asacontroltestontheuniformityofaproduct.Thissecondfunctionisparticularlyapplicabletosheet,rod,andtubearmswhenthetestismadeonthefinishedproduct.Comparisonofwaterabsorptionvaluesofvariousplasticscanbemadeonthebasisofvaluesobtainedinaccordancewith7.1and7.4.Idealdiffusionofliquidsintopolymersisafunctionofthesquarerootofimmersiontime.Timetosaturationisstronglydependentonspecimenthickness.Forexample,Table1showsthetimetoapproximatetimesaturationforvariousthicknessofnylon-6.Themoisturecontentofaplasticisveryintimatelyrelatedtosuchpropertiesaselectricalinsulationresistance,dielectriclosses,mechanicalstrength,appearance,anddimensions.Theeffectuponthesepropertiesofchangeinmoisturecontentduetowaterabsorptiondependslargelyonthetypeofexposure(byimmersioninwaterorbyexposuretohighhumidity),shapeofthepart,andinherentpropertiesoftheplastic.Withnonhomogeneousmaterials,suchaslaminatedforms,therateofwaterabsorptionmaybewidelydifferentthrougheachedgeandsurface.Evenforotherwisehomogeneousmaterials,itmaybeslightlygreaterthroughcutedgesthanthroughmoldedsurfaces.Consequently,attemptstocorrelatewaterabsorptionwiththesurfaceareamustgenerallybelimitedtocloselyrelatedmaterialsandtosimilarlyshapedspecimens:Formaterialsofwidelyvaryingdensity,relationbetweenwater-absorptionvaluesonavolumeaswellasaweightbasismayneedtobeconsidered.1.1Thistestmethodcoversthedeterminationoftherelativerateofabsorptionofwaterbyplasticswhenimmersed.Thistestmethodisintendedtoapplytothetestingofalltypesofplastics,includingcast,hot-molded,andcold-moldedresinousproducts,andbothhomogeneousandlaminatedplasticsinrodandtubeformandinsheets0.13mm[0.005in.]orgreaterinthickness.1.2ThevaluesgiveninSIunitsaretoberegardedasstandard.Thevaluesstatedinbracketsareforinformationonly.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.Note18212;ISO62istechnicallyequivalenttothistestmethod.
【中国标准分类号】:G31
【国际标准分类号】:83_080_01
【页数】:4P.;A4
【正文语种】:英语