ASTM C1303/C1303M-2010 预测闭孔绝缘泡沫的长期热电阻的标准试验方法

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【英文标准名称】:StandardTestMethodforPredictingLong-TermThermalResistanceofClosed-CellFoamInsulation
【原文标准名称】:预测闭孔绝缘泡沫的长期热电阻的标准试验方法
【标准号】:ASTMC1303/C1303M-2010
【标准状态】:现行
【国别】:美国
【发布日期】:2010
【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】:C16.30
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:aging;long-termthermalresistance;LTTR;rigidclosed-cellplasticfoams;scalingfactors;thermalinsulation;thermalresistance;time-averagedthermalresistance;Agingresistance;Controlledtestingconditions/environments;Foamed-in-placethermalin
【摘要】:Rigidgas-filledclosed-cellfoaminsulationsincludeallcellularplasticinsulationswhichrelyonablowingagent(orgas),otherthanair,forthermalresistancevalues.Atthetimeofmanufacture,thecellsofthefoamusuallycontaintheirhighestpercentageofblowingagentandthelowestpercentageofatmosphericgases.Astimepasses,therelativeconcentrationsofthesegaseschangedueprimarilytodiffusion.Thisresultsinageneralreductionofthethermalresistanceofthefoamduetoanincreaseinthethermalconductivityoftheresultantcellgasmixture.Thesephenomenaaretypicallyreferredtoasfoamaging.Forsomerigidgas-filledclosed-cellfoaminsulationproductsproducedusingblowingagentgasesthatdiffuseveryrapidlyoutofthefull-thicknessfoamproduct,suchasexpandedpolystyrene,thereisnoneedtoacceleratetheagingprocess.5.1.2Physicalgasdiffusionphenomenaoccurinthreedimensions.Theone-dimensionalformofthediffusionequationsusedinthedevelopmentofthispracticearevalidonlyforplanargeometries,thatis,forspecimensthathaveparallelfacesandwherethethicknessismuchsmallerthanthewidthandmuchsmallerthanthelength.Note28212;PleaseseeAppendixX3foradiscussionofthetheoryofacceleratedagingviathinslicing.Note38212;Theoreticalandexperimentalevaluationsoftheagingofinsulationinradialforms,suchaspipeinsulation,havebeenmade.(6)However,thesepracticeshavenotevolvedtothepointofinclusionintheteststandard.Thechangeinthermalresistanceduetothephenomenadescribedin5.1usuallyoccursoveranextendedperiodoftime.Informationregardingchangesinthethermalresistanceofthesematerialsasafunctionoftimeisrequiredinashorterperiodoftimesothatdecisionsregardingformulations,production,andcomparisonswithothermaterialscanbemade.SpecificationsC578,C591,C1029,C1126andC1289onrigidclosed-cellfoamsmeasurethermalresistanceafterconditioningat23x00B1;1x00B0;C[73x00B1;2x00B0;F]for180x00B1;5daysfromthetimeofmanufactureorat60x00B1;1x00B0;C[140x00B1;2x00B0;F]for90days.Thisconditioningcanbeusedforcomparativepurposes,butisnotsufficienttodescribelong-termthermalresistance.Thisrequirementdemonstratestheimportanceoftheagingphenomenawithinthisclassofproducts.ThePrescriptiveMethodinPartAprovideslong-termthermalresistancevaluesonaconsistentbasisforavarietyofpurposes,includingproductevaluation,specifications,orproductcomparisons.Theconsistentbasisforthesepurposesisprovidedbyaseriesofspecificproceduralconstraints,whicharenotrequiredintheResearchMethoddescribedinPartB.ThevaluesproducedbythePrescriptiveMethodcorrespondtothethermalresistanceatanageoffiveyears,whichcorrespondscloselytotheaveragethermalresistanceovera15-yearservicelife(7,8).Itisrecommendedthatanymaterialstan......