标准名称：	建筑石油沥青
英文名称：	Petroleum bitumens for architecture
中标分类：	石油 >> 石油产品 >> 石油沥青
替代情况：	被GB/T 494-1998代替
发布日期：	1985-08-23
实施日期：	1986-05-01
首发日期：
作废日期：	1998-12-01
出版日期：
页数：	2页

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【英文标准名称】:StandardTestMethodofMeasuringShrinkagefromMoldDimensionsofThermoplastics
【原文标准名称】:热塑塑料的模型尺寸收缩率测量的标准试验方法
【标准号】:ASTMD955-2008
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【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】:D20.09
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:moldshrinkage;shrinkage;thermoplastics;Molding/extrusioncompounds/materials;Moldshrinkage;Shrinkage--plastics;Thermosettingplastics
【摘要】:p>InjectionMolding8212;Ininjectionmolding,thedifferencebetweenthedimensionsofamoldcavityandofthemoldedspecimenmayvaryaccordingtothedesignofthemoldandoperationofthemoldingprocess.Factorssuchasmoldandmelttemperature,filltimes,andpackingconditionsareknowntoaffectshrinkagesignificantly.Adherencetothespecifiedmolddesign(see7.1)andspecificationsoutlinedinPracticeD3641orISO294-4ortheappropriatematerialspecificationwillimprovethereproducibilityofthetest.CompressionMolding8212;Incompressionmolding,thedifferencebetweenthedimensionsofamoldcavityandofthemoldedspecimenmayvaryaccordingtothedesignofthemoldandoperationofthemoldingprocess.Factors,suchastheamountofmaterialincharge,coolingtime,andpressureapplicationareknowntoaffectshrinkagesignificantly.Adherencetothespecifiedmolddesign(see7.2)andspecificationsoutlinedinPracticeD4703orISO293ortheappropriatematerialspecificationswillimprovethereproducibilityofthetest.1.1Thistestmethodisintendedtomeasureshrinkagefrommoldcavitytomoldeddimensionsofthermoplasticswhenmoldedbycompressionorinjectionprocesseswithspecifiedprocessconditions.1.2Thistestmethodcoversshrinkagemeasurementsat24and48h.1.3Thismethodwillgivecomparabledatabasedonstandardspecimensandcannotpredictabsolutevaluesinactualmoldedpartswithvaryingflowpaths,wallthicknesses,pressureandtemperaturegradientsandprocessconditions.Differencesinmoldshrinkagemayalsobeobservedamongthethreespecimengeometriesdescribedinthistestmethod.1.4ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesaregivenforinformationonly.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.Note18212;ThisstandardandISO294-3areequivalentinthedesignofspecimenD2.ThistestmethodisequivalenttoISO294-4whereTypeD2specimensandtheprocedureinAppendixX2areused.
【中国标准分类号】:G31
【国际标准分类号】:83_140_10
【页数】:5P.;A4
【正文语种】:英语