会员注册 | 登录 | 微信快捷登录 支付宝快捷登录 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

   首页 人人文库网 > 资源分类 > PDF文档下载

外文翻译--注塑成型中颗粒填充物聚丙烯的冷却情况 英文版.pdf

  • 资源星级:
  • 资源大小:341.97KB   全文页数:7页
  • 资源格式: PDF        下载权限:注册会员/VIP会员
您还没有登陆,请先登录。登陆后即可下载此文档。
  合作网站登录: 微信快捷登录 支付宝快捷登录   QQ登录   微博登录
友情提示
2:本站资源不支持迅雷下载,请使用浏览器直接下载(不支持QQ浏览器)
3:本站资源下载后的文档和图纸-无水印,预览文档经过压缩,下载后原文更清晰   

外文翻译--注塑成型中颗粒填充物聚丙烯的冷却情况 英文版.pdf

ofstryacceptedAbstractTherefore,polypropylenesampleswithdifferentcomCompositesPartA36Theeffectsofthermalpropertiesofvariousfillersmagnetite,barite,copper,talc,glassfibresandstrontiumferriteinvariousproportionsonthecoolingbehaviourofpolypropylenematrixcompositesareinvestigatedinaninjectionmouldingprocess.Athermocoupleinthecavityofthemouldrecordsthetemperaturesatthesurfaceofthecompositeduringinjectionmoulding.Fromtheslopeofthecoolingcurvesthethermaldiffusivitiesofthecompositesareestimatedandcomparedwiththermaldiffusivitiesatroomtemperatureandelevatedtemperaturesmeasuredwithatransienttechnique.Thecoolingcurvesshowdifferentmergingsectionsaffectedbytheafterpressure,thediffusivityofthecompositeandthediffusivityofpolypropylenematrix.Thecoolingbehaviourdependsontheanisotropicthermaldiffusivityoftheusedcomposite,whichiscausedbythealignmentoffillermaterialduetotheinjectionmouldingprocessandtheinterconnectivityofthefillerparticles.Thethermaldiffusivityshowsthehighestvaluefor30voltalcfilledpolypropylene,whereastheshortestcoolingtimewasfoundfor35volcopperfilledpolypropylene.Theknowledgeofthesystematicvariationofthermaltransportpropertiesofcompositesduetodifferentfillermaterialandfillerproportionsallowstooptimizethemouldprocessandtocustomizetheheatflowproperties.Furthermore,thestronglyanisotropicthermaltransportpropertiesoftalcfilledpolypropyleneallowthedesignofcompositeswithapredefinedmaximumheatflowcapabilitytotransportheatinapreferreddirection.KeywordsA.Polymer–matrixcompositesPMCsB.ThermalpropertiesE.InjectionmouldingParticulatefiller1.IntroductionCommonlyusedplastics,suchaspolypropyleneandpolyamide,havealowthermalconductivity.However,newapplications,mainlyinautomotiveindustries,e.g.forsensorsoractuators,requirenewmaterialswithanenhancedorhighthermalconductivity1.Bytheadditionofsuitablefillerstoplastics,thethermalbehaviourofpolymerscanbechangedsystematicallyuptosignificanthigherthermaldiffusivityofO1.2mm2/sfrom0.2mm2/sforunfilledpolypropylene2,3.Suchfilledpolymerswithhigherthermalconductivitiesthanunfilledonesbecomemoreandmoreanimportantareaofstudybecauseofthewiderangeofapplications,e.g.inelectronicpackaging4–6.Thehigherthermalconductivitycanbeachievedbytheuseofasuitablefillersuchasaluminium1,carbonfibresandgraphite7,aluminiumnitrides6,8ormagnetiteparticles2.Also,thecoolingbehaviourinthemouldoftheinjectionmouldingmachineisinfluencedbythethermalpropertiesofthepolymerfillercomposite.However,publishedvaluesofthermalconductivitiesofthesamefillermaterialsindifferentpolymermatricesvarydrasticallyandacomparisonofdifferentmaterialsisdifficultoratleastimpossible2.CoolingbehaviourofparticleinjectionmouldingBerndWeidenfellera,,MichaelaInstituteofPolymerScienceandPlasticsProcessing,TechnicalUniversitybGeoForschungsZentrumPotsdam,Section4.1ExperimentalGeochemiReceived25June2004filledpolypropyleneduringprocessHo¨ferb,FrankR.SchillingbClausthal,Agricolastrasse6,D38678ClausthalZellerfeld,GermanyandMineralPhysics,Telegrafenberg,D14473Potsdam,Germany4July20042005345–351talcandSrFe12O19werepreparedbyextrusionandinjectionmouldingusingvariousvolumefractions0–50.MagnetiteandbaritearegenerallyusedtoincreasetheweightofKochStr.42,D38678ClausthalZellerfeld,Germany.Tel.C495323723708faxC495323723148.Emailaddressbernd.weidenfellertuclausthal.deB.Weidenfeller.Correspondingauthor.PresentaddressInstituteofMetallurgy,RobertmerciallyavailablefillersFe3O4,BaSO4,Cu,glassfibres,3.ExperimentalTalc,Mg3Si4O10OH2Strontiumferrite,SrFe12O19Copper,CuGlassfibresl111.76G0.00,l3310.69G1.35,a2.97,a3.00G0.10,a6.10G0.90l11401l1.2–1.51314152.01.51511PlateletIrregularIrregularFibre2.785.118.942.58aretesPartA362005345–3512.TheoreticalconsiderationsTheFourierlawofheattransportinonedimensionisgivenbyvTvtZav2Tvx21withtemperatureT,timet,positionxandthermaldiffusivitya.Inanhomogeneousbody,thermaldiffusivityaandthermalconductivitylareinterrelatedbyspecificdensityrpolypropylene,e.g.forbottleclosurescosmeticsindustry,cf.Ref.10,strontiumferriteisusedinpolymerbondedmagnets,glassfibresareusedforthereinforcementofmaterials,andtalcisanantiblockingagent.However,copperwaschosenasadditionalfillerbecauseofitshighthermalconductivitycomparedtotheothermaterials.Thethermalpropertiesoftheseinjectionmouldedsamplesandtheinjectionmouldingbehaviourwereinvestigatedandcorrelatedtotheamountandthekindoffillermaterial.Table1SelectedpropertiesoffillermaterialsMagnetite,Fe3O4Barite,BaSO4ThermalconductivityW/mKa4.61G0.42,a5.10,l119.7l112.07G0.02,l332.92G0.07,a1.72G0.04Reference1313Meanparticlediametermm91.5ParticleshapeIrregularIrregularDensityg/cm35.14.48adenotesmeasurementsonmonomineralicaggregates.Directionsofanisotropyandl33areparalleltothecrystallographicaxesa,bandc,respectively.B.Weidenfelleretal./Composi346andspecificheatcapacitycpaccordingtolZcpra2AssuminganinjectionmouldingprocesswithanisothermalfillingstageforapolymerwithatemperatureTPandaconstanttemperatureofthemouldTMaswellasatemperatureindependentthermaldiffusivitya,ananalyticalsolutionofEq.1resultsin9TZTMC4pðTPKTMÞXNnZ012nC1expKað2nC1Þ2p2ts2C26C27sinð2nC1ÞpxsC18C193InEq.3,sdenotesthewallthicknessoftheinjectionmouldedpartandTthetemperatureofthemouldingafter3.1.MaterialsTestmaterialsweresuppliedbyMinelcoB.V.TheNetherlands.MinelcoB.V.preparedincooperationwithRTPs.a.r.lFranceseveralpolypropylenePPcompoundswithvariousfillersFe3O4,BaSO4,Cu,glassfibres,talcandSrFe12O19inanextrusionprocesssimilartothatdescribedinRef.2.Thefillermaterialsarecommonlyusedmaterialsinindustrialproducts.Thefillerparticlesdonothaveatimetafterinjection.Neglectinghigherorderterms,Eq.3canbereducedforthepositionxZs/2toTZTMC4pðTPKTMÞexpKap2ts2C18C19C26C274Eq.4givesarelationbetweencoolingrateandthermaldiffusivityinaninjectionmouldingprocess,wherehighthermaldiffusivitiesresultinahighercoolingrateandshorterprocesscycles.specifiedbythethermalconductivitytensorl11,l22,l33,wherel11,l22surfacecoatingwhichcanaffectthermalproperties.SomeselectedpropertiesofthefillermaterialsarelistedinTable1.Fig.1.Photographoftheusedmouldfortheinjectionmouldingexperiments.Themouldconsistsofastandardtensiletestsampleandatestbarforthemeasurementofthermaldiffusivity.timecurvesthesameinjectionmouldingparametersforallcompositematerialswerechosen.Theusedinjectionmachine.ThepositionofthethermocouplefortemperaturemeasurementsisPartA362005345–3513473.2.ThermaldiffusivitymeasurementsThethermaldiffusivityofthepolymersismeasuredbyatransientmethod12,closelyrelatedtolaserflashexperiments11.Theusedtransienttechniqueisespeciallyoptimizedformeasurementsofpolyphaseaggregates.Atemperaturesignalistransferredtotheuppersideofthesampleandregisteredbyathermocouple.Thetransferredtemperaturesignalstartsathermalequilibrationprocessinthespecimen,whichisrecordedbyathermocoupleasthedifferencebetweensamplesrearsurfaceandaconstanttemperatureinafurnaceandwhichisusedfortheevaluationofthermaldiffusivity.Aleastsquaresalgorithmisusedtodeterminethethermaldiffusivity,whilevaryingsystematicallythethermaldiffusivityvalueinanespeciallyFig.2.Moldwithcavityforpreparingtestsamplesinaninjectionmouldingmarkedbyanarrow.B.Weidenfelleretal./Compositesdesignedfinitedifferencescheme.AdetaileddescriptionoftheapparatusisgivenbySchilling12.Theaccuracyofthemeasurementsofthepolyphaseaggregatesis3.Forthermaldiffusivitymeasurements,smallcylindersof10mmdiameterand5–6mmheightwerecutoutoftheinjectionmouldedrodscf.Fig.1.3.3.InjectionmouldingWithaninjectionmouldingmachineAllrounder320C600250,Arburg,Germanystandardsamplesformeasuringtensilepropertiestogetherwitharodforthermalmeasurementsof10mmdiameterand130mmlengthwerepreparedinonemouldcf.Fig.1.InthecavityofthetensiletestbarachromelalumelTypeKthermocouplewasapplied.Duringinjectionmouldingexperimentsthetemperaturewasrecordedevery0.5sbyadigitalmultimeterandstoredinapersonalcomputer.ThepositionofthethermocoupleatthesamplesurfaceanditspositioninthecavityoftheejectorareshowninFigs.1and2,respectively.Thethermocouplesubmergesapproximately0.2mmintomouldingparametersarelistedinTable2.TheresultantcharacteristictimesoftheinjectionmouldingcyclearetabledinTable3.4.ResultsanddiscussionInFig.3,thecoolingbehaviourofpolypropylenewithoutandwithvariousfractionsofmagnetitefillerarepresented.thecavity.Therefore,agoodthermalcontactbetweenpolymerandthermocoupleevenaftershrinkage10ofthemouldingisensured.Forabettercomparisonoftherecordedtemperature–Table3CharacteristictimesinoneinjectionmouldingcyclestartingwiththeinjectionofthepolymerintothecavityattimetiZK8.5suntiltheejectionofthemouldattfZ68sInjectiontimesK8.5–2Dwelltimes2–9Coolingtimes9–54Open/closetimeejectiontimes54–68Totalcycletimes76.5ThesetimesdefinethetimeaxisabscissaofFigs.3and6.Table2InjectionmouldingparametersduringpreparationofsamplerodsformeasurementsofthermaldiffusivitybytransienttechniqueMasspolymertemperature8C200Mouldtemperature8C20Cycletimes76.5Injectiontimes10.5Dosingtimes12.4Holdingpressuretimes7.0InjectionpressurePa6107ylenecompositeswithvariousfillerfractionsofFe3O4.ThesymbolsaremeasuredtesPartA362005345–351Atatimet0Z0sthetemperaturemeasuredbythethermocouplereachesamaximumvaluearound2008C.Withincreasingtimetheobservedtemperaturedecreases.AftertZ54sthemouldopensandthecoolingbehaviourrecordedwiththethermocouplechangesbecauseitisnolongerincontactwiththeinjectionmouldedmaterial.Duetothelargediameteroftherod,thetime54suntilthemouldisopenedandtheinjectionmouldedpartsareejectedischosenrelativelyhightoensurethatthepartsaresurelysolidified.ItcanbeseeninFig.3thattheslopeofthecurvechangessignificantlyaftertz9s,whichcorrespondstothetimeFig.3.Comparisonofcoolingcurvesofunfilledpolypropylenewithpolypropvaluesthelinesareregressionlinescf.text.B.Weidenfelleretal./Composi348wheretheafterpressureisremoved.Additionally,Fig.3pointsoutthatthecompositeinthecavitycoolsdownfasterwithincreasingmagnetitefraction.ToreachatemperatureofTZ608CatemperaturefarbelowthesolidificationofthesamplethepolypropyleneneedsinthedescribedexperimentatimeoftZ50.5s,whereascoolingtimeofpolypropylenewith50volFe3O4isreducedtotZ30.9scf.Table4.Thereducedcoolingtimeisingoodagreementwiththeincreasedthermaldiffusivityofmagnetitefilledcompositesduetothehighthermaldiffusivityoftheparticlescf.Table1whichleads,regardingEq.4,toanincreasedcoolingrate.ThetemperaturetimedependenceinFig.3doesnotfollowasimplelinearbehaviourexpectedfortemperature–timecurvesbyEq.4inalogarithmicplot.Onlyfortheunfilledpolypropylenethemeasuredvaluescanbefittedwithasinglestraightlinebetweenapproximately15and54s.Theslopeofthislineleadstoadiffusivityofaz0.21mm2/scf.Eq.4.Theothermeasuredcoolingcurvesofthepolypropylenemagnetitecompositesarefittedineachcasewithtwostraightlines,forthehightemperaturea1andlowtemperaturea2region.Thethermaldiffusivitiesestimatedfromtheslopesoftheregressionlinesarea115st40sz0.24mm2/sanda241st54sz0.19mm2/sforPPwith15volFe3O4,a112st33sz0.29mm2/sanda234st54sz0.19mm2/sforPPwith30volFe3O4,anda19st22sz0.33mm2/sanda228st54sz0.16mm2/sforPPwith50volFe3O4cf.Table5.Itisremarkablethatthecalculatedthermaldiffusivitiesa1ofthehighertemperaturepartsofthecoolingcurvesarealittlebitlowerthanthediffusivitiesmeasuredwiththetransienttechnique,whilethecalculatedthermaldiffusivitiesa2ofthelowertemperaturepartsofthecoolingcurvesmeetthemeasureddiffusivityvaluesTable4TimettocooldownapolypropylenefillercompositefromamasspolymertemperatureofTMZ200downto608CCompositeFillerfractionvoltfrom200to608CsPP050.5PPCFe3O41546.4PPCFe3O43040.5PPCFe3O44534.6PPCFe3O45034.9PPCBaSO41544.3PPCBaSO43040.7PPCBaSO44535.6PPCCu1540.5PPCCu3033.8PPCCu3529.0PPCglassfibres1546.0PPCglassfibres3041.8PPCglassfibres3540.8PPCtalc1545.7PPCtalc3042.5PPCSrFe12O193040.9ThecoolingismeasuredinsituwithinacavityofthemouldbyaKtypethermocouple.

注意事项

本文(外文翻译--注塑成型中颗粒填充物聚丙烯的冷却情况 英文版.pdf)为本站会员(英文资料库)主动上传,人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知人人文库网([email protected]),我们立即给予删除!

温馨提示:如果因为网速或其他原因下载失败请重新下载,重复下载不扣分。

copyright@ 2015-2017 人人文库网网站版权所有
苏ICP备12009002号-5