【英文标准名称】:StandardTestMethodforMeasuringShrinkagefromMoldDimensionsofMoldedThermosettingPlastics
【原文标准名称】:测量由模制热固塑料的模型尺寸收缩的标准试验方法
【标准号】:ASTMD6289-2008
【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】:moldingshrinkage;post-moldingshrinkage;thermosetplastics;Compression-moldedplasticspecimens;Injectionmolding/extrusioncompounds;Molding/extrusioncompounds/materials;Moldingshrinkage;Post-moldingshrinkage;Shrinkage--plastics;Thermosettin
【摘要】:CompressionMolding8212;Incompressionmolding,thedifferencebetweenthedimensionsofamoldandofthemoldedarticleproducedthereinfromagivenmaterialvaryaccordingtothedesignandoperationofthemold.Itisprobablethatshrinkagewillapproachaminimumwheredesignandoperationaresuchthatamaximumofmaterialisforcedsolidlyintothemoldcavityorsomepartofit,orwherethemoldedarticleishardenedtoamaximumwhilestillunderpressure,particularlybycooling.Incontrast,shrinkagesarehigherwherethechargemustflowinthemoldcavitybutdoesnotreceiveandtransmitenoughpressuretobeforcedfirmlyintoallitsrecesses,orwherethemoldedarticleisnotfullyhardenedwhendischarged.Theplasticityofthematerialusedaffectsshrinkageinsofarasitaffectstheretentionandcompressionofthecharge.InjectionMolding8212;Ininjectionmolding,asincompressionmolding,thedifferencesbetweenthedimensionsofthemoldandofthemoldedarticleproducedthereinfromagivenmaterialvaryaccordingtothedesignandoperationofthemold.Thedifferencesvarywiththetypeandsizeofmoldingmachine,thethicknessofmoldedsections,thedegreeanddirectionofflowormovementofmaterialinthemold,thesizeofthenozzle,sprue,runner,andgate,thecycleonwhichthemachineisoperated,thetemperatureofthemold,andthelengthoftimethatfollow-uppressureismaintained.Asinthecaseofcompressionmolding,shrinkageswillapproachaminimumwheredesignandoperationaresuchthatamaximumofmaterialisforcedsolidlyintothemoldcavityandwherethemoldedarticleishardenedtoamaximumwhilestillunderpressureasaresultoftheuseofarunner,sprue,andnozzleofpropersize,alongwithproperdwell.Asincompressionmolding,shrinkagesarehigherwherethechargemustflowinthemoldcavitybutdoesnotreceiveandtransmitenoughpressuretobeforcedfirmlyintoalloftherecessesofthemold.Theplasticityofthematerialusedaffectsshrinkageindirectly,inthatthemorereadilyplasticizedmaterialwillrequirealowermoldingtemperature.TransferMolding8212;Intransfermolding,asincompressionorinjectionmolding,thedifferencebetweenthedimensionsofthemoldandofthemoldedarticleproducedthereinfromagivenmaterialvaryaccordingtothedesignandoperationofthemold.Itisaffectedbythesizeandtemperatureofthepotorcylinderandthepressureonit,aswellasonmoldtemperatureandmoldingcycle.Directionofflowisnotasimportantafactor.MaterialsStandards8212;Alwaysrefertomaterialstandardsforspecialtreatmentpriortomolding,moldingconditionsandspecialhandlingofthetestspecimensaftermolding.Intheeventthematerialstandardisunavailable,contactthemanufacturerfortheserecommendations.Utility8212;Measurementofbatch-to-batchconsistencyininitialshrinkagefrommoldtomoldeddimensionsisusefulforevaluatingthequalityofthermosettingplastics.1.1Thistestmethodisintendedtomeasureshrinkagefrommoldcavitytomoldeddimensionsofthermosettingplasticswhenmoldedbycompression,injection,ortransferunderspecifiedconditions.1.2Thistestmethodprovidesforthemeasurementofshrinkageofthermosettingplasticsfromtheirmoldsbothinitially(within16to72hofmolding)andastheyage(postx2013;shrinkageatelevatedtemperatures).1.3Thismethodwillgivecomparabledatabasedonstandardspecimensandcannotpredictabsolutevaluesinactualmol......
【中国标准分类号】:G31
【国际标准分类号】:83_080_10
【页数】:4P.;A4
【正文语种】:英语