会员注册 | 登录 | 微信快捷登录 QQ登录 微博登录 | 帮助中心 人人文库renrendoc.com美如初恋!
站内搜索 百度文库

热门搜索: 直缝焊接机 矿井提升机 循环球式转向器图纸 机器人手爪发展史 管道机器人dwg 动平衡试验台设计

外文翻译--PBT玻璃纤维增强复合材料水辅注塑成型的实验研究 英文.pdf外文翻译--PBT玻璃纤维增强复合材料水辅注塑成型的实验研究 英文.pdf -- 5 元

宽屏显示 收藏 分享

资源预览需要最新版本的Flash Player支持。
您尚未安装或版本过低,建议您

form7NovemberFig.1.Waterassistedinjectionmoldingcanproducepartsincorporatingboththickandthinsectionswithlessshrinkinvolved.Watermayalsocorrodethesteelmold,andsomematerialsincludingthermoplasticcompositesaredifficulttomoldsuccessfully.Theremovalofwateraftermoldingisalsoachallengeforthisnoveltechnology.Table1liststheadvantagesandlimitationsofwaterassistedinjectionmoldingtechnology.Correspondingauthor.Address259,WenHwa1stRoad,KweiSan,TaoYuan333,Taiwan.Emailaddressshihjungmail.cgu.edu.twS.J.Liu.CompositesScienceandTechnologyCOMPOSITES1.IntroductionWaterassistedinjectionmoldingtechnology1hasproveditselfabreakthroughinthemanufactureofplasticpartsduetoitslightweight,fastercycletime,andrelativelylowerresincostperpart.Inthewaterassistedinjectionmoldingprocess,themoldcavityispartiallyfilledwiththepolymermeltfollowedbytheinjectionofwaterintothecoreofthepolymermelt.Aschematicdiagramofthewaterassistedinjectionmoldingprocessisillustratedinageandwarpageandwithabettersurfacefinish,butwithashortercycletime.Thewaterassistedinjectionmoldingprocesscanalsoenablegreaterfreedomofdesign,materialsavings,weightreduction,andcostsavingsintermsoftoolingandpresscapacityrequirements2–4.Typicalapplicationsincluderodsandtubes,andlargesheetlikestructuralpartswithabuiltinwaterchannelnetwork.Ontheotherhand,despitetheadvantagesassociatedwiththeprocess,themoldingwindowandprocesscontrolaremorecriticalanddifficultsinceadditionalprocessingparametersareAbstractThepurposeofthisreportwastoexperimentallystudythewaterassistedinjectionmoldingprocessofpolybutyleneterephthalatePBTcomposites.Experimentswerecarriedoutonan80toninjectionmoldingmachineequippedwithalabscalewaterinjectionsystem,whichincludedawaterpump,apressureaccumulator,awaterinjectionpin,awatertankequippedwithatemperatureregulator,andacontrolcircuit.ThematerialsincludedvirginPBTanda15glassfiberfilledPBTcomposite,andaplatecavitywitharibacrosscenterwasused.Variousprocessingvariableswereexaminedintermsoftheirinfluenceonthelengthofwaterpenetrationinmoldedparts,andmechanicalpropertytestswereperformedontheseparts.XraydiffractionXRDwasalsousedtoidentifythematerialandstructuralparameters.Finally,acomparisonwasmadebetweenwaterassistedandgasassistedinjectionmoldedparts.Itwasfoundthatthemeltfillpressure,melttemperature,andshortshotsizewerethedominantparametersaffectingwaterpenetrationbehavior.Materialatthemoldsideexhibitedahigherdegreeofcrystallinitythanthatatthewaterside.Partsmoldedbygasalsoshowedahigherdegreeofcrystallinitythanthosemoldedbywater.Furthermore,theglassfibersnearthesurfaceofmoldedpartswerefoundtobeorientedmostlyintheflowdirection,butorientedsubstantiallymoreperpendiculartotheflowdirectionwithincreasingdistancefromtheskinsurface.C2112006ElsevierLtd.Allrightsreserved.KeywordsWaterassistedinjectionmoldingGlassfiberreinforcedpolybutyleneterephthalatePBTcompositesProcessingparametersB.MechanicalpropertiesCrystallinityA.PolymermatrixcompositesProcessingAnexperimentalstudyofthewaterassistedglassfiberfilledpolybutyleneterephthalateShihJungLiu,MingJenPolymerRheologyandProcessingLab,DepartmentofMechanicalReceived12September2005receivedinrevisedAvailableonline02663538/seefrontmatterC2112006ElsevierLtd.Allrightsreserved.doi10.1016/j.compscitech.2006.09.016injectionmoldingofPBTcompositesLin,YiChuanWuEngineering,ChangGungUniversity,TaoYuan333,Taiwan29June2006accepted11September20062006www.elsevier.com/locate/compscitech6720071415–1424SCIENCEANDTECHNOLOGYTable2AcomparisonofwaterandgasassistedinjectionmoldingWaterGas1.CycletimeShortLong2.MediumcostLowHigh3.InternalfoamingNoYes4.ResidualwallthicknessSmallLarge5.OutsidesurfaceroughnessLowHigh6.OutsidesurfaceglossHighLow1416S.J.Liuetal./CompositesScienceandTechnology6720071415–1424Waterassistedinjectionmoldinghasadvantagesoveritsbetterknowncompetitorprocess,gasassistedinjectionmolding5,becauseitincorporatesashortercycletimetosuccessfullymoldapartduetothehighercoolingcapacFig.1.Schematicdiagramofwaterassistedinjectionmoldingprocess.ityofwaterduringthemoldingprocess.Theincompressibility,lowcost,andeaseofrecyclingthewatermakesitanidealmediumfortheprocess.Sincewaterdoesnotdissolveanddiffuseintothepolymermeltsduringthemoldingprocess,theinternalfoamingphenomenon6thatusuallyoccursingasassistedinjectionmoldedpartscanbeeliminated.Inaddition,waterassistedinjectionmoldingprovidesabettercapabilityofmoldinglargerpartswithasmallresidualwallthickness.Table2listsacomparisonofwaterandgasassistedinjectionmolding.Withincreasingdemandsformaterialswithimprovedperformance,whichmaybecharacterizedbythecriteriaoflowerweight,higherstrength,andafasterandcheaperproductioncycletime,theengineeringofplasticsisaprocessthatcannotbeignored.Theseplasticsincludethermoplasticandthermosetpolymers.Ingeneral,thermoplasticpolymershaveanadvantageoverthermosetpolymersinTable1AdvantagesanddisadvantagesofwaterassistedinjectionmoldingAdvantagesDisadvanta1.Shortcycletime2.Lowassistingmediumcostwaterismuchcheaperandcanbeeasilyrecycled3.Nointernalfoamingphenomenoninmoldedparts1.2.3.4.termsofhigherimpactstrength,fractureresistanceandstrainstofailure.Thismakesthermoplasticpolymersverypopularmaterialsinstructuralapplications.PolybutyleneterephthalatePBTisoneofthemostfrequentlyusedengineeringthermoplasticmaterials,whichisformedbypolymerizing1.4butyleneglycolandDMTtogether.Fiberreinforcedcompositematerialshavebeenadaptedtoimprovethemechanicalpropertiesofneatplasticmaterials.Today,shortglassfiberreinforcedPBTiswidelyusedinelectronic,communicationandautomobileapplications.Therefore,theinvestigationoftheprocessingoffiberreinforcedPBTisbecomingincreasinglyimportant7–10.ThisreportwasmadetoexperimentallystudythewaterassistedinjectionmoldingprocessofpolybutyleneterephthalatePBTmaterials.Experimentswerecarriedoutonan80toninjectionmoldingmachineequippedwithalabscalewaterinjectionsystem,whichincludedawaterpump,apressureaccumulator,awaterinjectionpin,awatertankequippedwithatemperatureregulator,andacontrolcircuit.ThematerialsincludedavirginPBTanda15glassfiberfilledPBTcomposite,andaplatecavity7.FingeringGreaterLess8.AsymmetricalpenetrationMorestableUnstable9.MaterialcrystallinityLowHigh10.ParttransparencyHighLow11.InternalsurfacesemicrystallinematerialsSmoothLesssmooth12.InternalsurfaceamorphousmaterialsRoughSmoothwitharibacrosscenterwasused.Variousprocessingvariableswereexaminedintermsoftheirinfluenceonthelengthofwaterpenetrationinmoldedparts,whichincludedmelttemperature,moldtemperature,meltfillingspeed,shortshotsize,waterpressure,watertemperature,waterholdandwaterinjectiondelaytime.Mechanicalpropertytestswerealsoperformedonthesemoldedparts,andXRDwasusedtoidentifythematerialandstructuralgesCorrosionofthesteelmoldduetowaterLargerorificesfortheinjectionpinrequiredeasiertogetstuckbythepolymermeltSomematerialsaremoredifficulttomoldespeciallyamorphousthermoplasticsRemovalofwateraftermoldingisrequiredparameters.Finally,acomparisonwasmadebetweenwaterassistedandgasassistedinjectionmoldedparts.2.Experimentalprocedure2.1.MaterialsThematerialsusedincludedavirginPBTGrade1111FB,NanYaPlastic,Taiwananda15glassfiberfilledPBTcompositeGrade1210G3,NanYaPlastic,Taiwan.Table3liststhecharacteristicsofthecompositematerials.polymermelt.Table4liststheseprocessingvariablesaswellasthevaluesusedintheexperiments.2.4.GasinjectionunitInordertomakeacomparisonofwaterandgasassistedinjectionmoldedparts,acommerciallyavailablegasinjectionunitGasInjectionPPC1000wasusedforthegasassistedinjectionmoldingexperiments.DetailsofthegasinjectionunitsetupcanbefoundintheRefs.11–15.TheprocessingconditionsusedforgasassistedinjectionmoldingwerethesameasthatofwaterassistedinjectionmoldingtermsinboldinTable4,withtheexceptionofgastemperaturewhichwassetat25C176C.2.5.XRDInordertoanalyzethecrystalstructurewithinthewaterassistedinjectionmoldedparts,wideangleXraydiffractionXRDwith2DdetectoranalysesintransmissionmodewereperformedwithCuKaradiationat40kVand40mA.Morespecifically,themeasurementswereperformedonthemoldsideandwatersidelayersofthewaterassistedinjectionmoldedparts,withthe2hanglerangingfrom7C176to40C176.ThesamplesrequiredfortheseanalysesweretakenfromthecenterportionoftheseFig.2.Layoutanddimensionsofmoldcavityunitmm.S.J.Liuetal./CompositesScienceand2.2.WaterinjectionunitAlabscalewaterinjectionunit,whichincludedawaterpump,apressureaccumulator,awaterinjectionpin,awatertankequippedwithatemperatureregulator,andacontrolcircuit,wasusedforallexperiments3.Anorificetypewaterinjectionpinwithtwoorifices0.3mmindiameteronthesideswasusedtomoldtheparts.Duringtheexperiments,thecontrolcircuitofthewaterinjectionunitreceivedasignalfromthemoldingmachineandcontrolledthetimeandpressureoftheinjectedwater.Beforeinjectionintothemoldcavity,thewaterwasstoredinatankwithatemperatureregulatorfor30mintosustainanisothermalwatertemperature.2.3.MoldingmachineandmoldsWaterassistedinjectionmoldingexperimentswereconductedonan80tonconventionalinjectionmoldingmachinewithahighestinjectionrateof109cm3/s.Aplatecavitywithatrapezoidalwaterchannelacrossthecenterwasusedinthisstudy.Fig.2showsthedimensionsofthecavity.Thetemperatureofthemoldwasregulatedbyawatercirculatingmoldtemperaturecontrolunit.Variousprocessingvariableswereexaminedintermsoftheirinfluenceonthelengthofwaterpenetrationinwaterchannelsofmoldedpartsmelttemperature,moldtemperature,meltfillpressure,watertemperatureandpressure,waterinjectiondelaytimeandholdtime,andshortshotsizeoftheTable3Characteristicsoftheglass–fiberreinforcedPBTcompositePropertyASTMPBT15G.F.PBTYieldstrengthkg/cm2D6386001000Bendingstresskg/cm2D5709001500HardnessRscaleD785119120HeatdistortiontemperatureC176C18.6kg/cm2D64860200MeltflowindexMFID12384025ImpactstrengthKgcm/cmD25655MeltingtemperatureC176CDSC224224Technology6720071415–14241417moldedparts.ToobtainthedesiredthicknessfortheXRDsamples,theexcesswasremovedbypolishingthesamplesonarotatingwheelonarotatingwheel,firstwithwetsiliconcarbidepapers,thenwith300gradesiliconcarbidepaper,followedby600and1200gradepaperforabettersurfacesmoothness.2.6.MechanicalpropertiesTensilestrengthandbendingstrengthweremeasuredonatensiletester.TensiletestswereperformedonspecimensobtainedfromthewaterassistedinjectionmoldedpartsseeFig.3toevaluatetheeffectofwatertemperatureon20mm10mm1mm.BendingtestswereperformedinamicrotensiletesteraccordingtotheASTMD256test.A200Nloadcellwasusedandthecrossheadspeedwas50mm/min.2.7.MicroscopicobservationThefiberorientationinmoldedspecimenswasobservedunderascanningelectronmicroscopeJeolModel5410.SpecimensforobservationwerecutfrompartsmoldedbywaterassistedinjectionmoldingacrossthethicknessTable4TheprocessingvariablesaswellasthevaluesusedintheexperimentsABCDEFMeltpressureMpaMelttemperatureC176CShortshotsizeWaterpressureMpaWatertemperatureC176CMoldtemperatureC176C140280270768808012627526577975751142702607810707098265255801165658426025081126060ThevaluesintheparenthesesarethemelttemperaturesusedforvirginPBTmaterials.1418S.J.Liuetal./CompositesScienceandTechnology6720071415–1424thetensileproperties.Thedimensionsofspecimensfortheexperimentswere30mm10mm1mm.TensiletestswereperformedinaLLOYDtensiometeraccordingtotheASTMD638Mtest.A2.5kNloadcellwasusedandthecrossheadspeedwas50mm/min.Bendingtestswerealsoperformedatroomtemperatureonwaterassistedinjectionmoldedparts.ThebendingspecimenswereobtainedwithadiecutterfrompartsFig.3subjectedtovariouswatertemperatures.ThedimensionsofthespecimenswereFig.3.Schematically,thepositioningofthesamplescutfromthemoldedFig.3.Theywereobservedonthecrosssectionperpendiculartotheflowdirection.Allspecimensurfacesweregoldsputteredbeforeobservation.3.ResultsanddiscussionAllexperimentswereconductedonan80tonconventionalinjectionmoldingmachine,withahighestinjectionrateof109cm3/s.Aplatecavitywithatrapezoidalwaterchannelacrossthecenterwasusedforallexperiments.partsfortensileandbendingtestsandmicroscopicobservations.
编号:201311171103185670    大小:432.45KB    格式:PDF    上传时间:2013-11-17
  【编辑】
5
关 键 词:
教育专区 外文翻译 精品文档 外文翻译
温馨提示:
1: 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
2: 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
3.本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 人人文库网仅提供交流平台,并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
  人人文库网所有资源均是用户自行上传分享,仅供网友学习交流,未经上传用户书面授权,请勿作他用。
0条评论

还可以输入200字符

暂无评论,赶快抢占沙发吧。

当前资源信息

4.0
 
(2人评价)
浏览:11次
英文资料库上传于2013-11-17

官方联系方式

客服手机:17625900360   
2:不支持迅雷下载,请使用浏览器下载   
3:不支持QQ浏览器下载,请用其他浏览器   
4:下载后的文档和图纸-无水印   
5:文档经过压缩,下载后原文更清晰   

相关资源

相关资源

相关搜索

教育专区   外文翻译   精品文档   外文翻译  
关于我们 - 网站声明 - 网站地图 - 友情链接 - 网站客服客服 - 联系我们
copyright@ 2015-2017 人人文库网网站版权所有
苏ICP备12009002号-5