喜歡就充值下載吧。。資源目錄里展示的文件全都有，，請(qǐng)放心下載，，有疑問咨詢QQ:414951605或者1304139763 ======================== 喜歡就充值下載吧。。資源目錄里展示的文件全都有，，請(qǐng)放心下載，，有疑問咨詢QQ:414951605或者1304139763 ======================== PertanikaJ.Sci.&Techno!. Supplement12(2):85- 99 (2004)ISSN: 0128-7680Universiti Putra Malaysia PressDesign and SimulationofPlastic Injection Moulding ProcessWong, C.T.,ShamsuddinSulaiman,NapsiahIsmail&A.M.S.HamoudaDepartmentofMechanical and Manufacturing EngineeringUniversiti Putra Malaysia, 43400UPM,Serdang,Selangor,MalaysiaE-mails:.my.suddineng.upm.edu.my.napsiaheng.upm.edu.my.hamoudaeng.upm.edu.myABSTRAKKertas inimembentangkanprosesrekabentuksatuacuansuntikan plastikuntukmenghasilkan satuproduk.Ia dibahagikankepadatigabahagianiaitu:bahagianrekabentuk,bahagiansimulasidanbahagiananalisa. Plastikprodukini direkabentukkepadaduabentukyangberlainantetapi mempunyai fungsi yang sama iaitu satuprodukmenggunakanfungsi klipdansatuproduklagimenggunakanfungsi lekat.UntukRekaBentukTerbantuKomputer(CAD), perisiankomputeryangdigunakanuntukmerakabentukprodukdalam3 dimensi (3D)danacuanialahPro/Engineer(Pro/E).Duaplastikprodukyangberlainanakan direkabentukdalaminse:rtyangbolehditukar-tukardidalam satuacuanuntukmenghasilkanduaprodukyang berlainan.UntukPembuatanTerbantuKomputer(CAM),Pro/Manufacturing(Pro/MFG)daripadaperisiankomputerProlEdigunakanuntukmenjanakanbeberapakod kawalanberangkauntukprosespemesinan.Analisisterhadappengalirancecair plastik dijalankandenganmenggunakanperisian (MoldFIow -PartAdvisor version 4).Daripadaanalisis inikedudukantempatsuntikan,suhubahandantekanansuntikandapatditentukan.Jangkaankecacatanproduksepertiweld linesdanudaraterperangkapjugaditemuidandianalisis.ABSTRACfThispaperpresentsthe designofplastic injectionmouldforproducinga plasticproduct.Theplasticpartwasdesignedintotwodifferenttypesofproduct,butinthesame usagefunction.Onepartisusingclip functionandanotherpartisusing tick function.Inthecomputer-aideddesign (CAD), two plastic parts were drawn in 3dimension(3D) view byusingPro-Engineer(Pro-E)parametricsoftware.Inthecomputer-aidedmanufacturing(CAM), Pro-Manufacturing from Pro-Eparametricsoftwarewasused to developthemachiningprogram.Formoulddesign,theproductwasdesignedintotwochangeableinserts toproducetwodifferenttypesofplasticproductinonemouldbase. Beforeproceedingto injectionmachineandmoulddesign, thispartwasanalysedandsimulatedbyusing Mold FloworPartAdvisor software.Fromtheanalysisandsimulationwecandefinethemostsuitable injection location, materialtemperatureandpressure forinjection.Thepredictedweld linesandairtrapwere alsofoundandanalysed.Keywords: Changeableinsertmould,injectionpressure,airtraps, injection location,moulddesignINTRODUCTIONNowadays,thetechnologyofthetoolanddiefabricationinplasticinjectionisoneoftheworldsfastest growing industries. Plastic is nowusedinalmostevery application,rangingfromhouseholdarticlestospacetravel, fromtransportationtopacking,frommedicinetotoys,frombridgebuildingtosports. Generally,injectionmouldingisaprocessthatformstheplasticintoadesiredshapebymeltingtheplasticmaterialandforcingtheplasticmaterialunderpressureintothemouldcavity.Theshapeoftheplasticthatisdesiredisachievedbycoolinginthermoplasticorbychemicalreactionforthermosetting.Moulddesignandfabricationisa costlyandhightechnologyprocessbecauseit usesscience-basedcomputer-aidedengineering(CAE) software to analyseandsimulatetheWong, C.T.,ShamsuddinSulaiman,NapsiahIsmail&A.M.S.Hamoudaplastic parts,computer-aideddesign (CAD)softwareto designthecomplicatedplasticproductandcomputer-aidedmanufacturing(CAM)todotheprogrammingfabricationtorunthecomputernumericcontrol(CNC)formillingorlatch. Advances incomputertechnology haveledtoanincreasingly favorablepowerto cost ratioforcomputers. Sothis advantageousandcostly technology willimproveproductivityandprocess consistency.Thus, for this fast growing industry, newtechnologiesarevital toensurethatthistechnologyreachesperfection.S.ocomputer-aidedengineering(CAE) istheassistant toprocessandcalculatetheplastic material flowinsidetheinjectionmoulding.TheoryHow Plastic Fills a MouldTheinjectionmouldingprocesscanbebrokenintothreephases:1.Fillingphase2.Pressurizationphase3.CompensatingphaseFilling PhaseWhendesigning plasticpartsfortheinjectionmouldingprocess,theimportantelementtounderstandishowtheplasticisfillinginthemould.Inthemouldinjection fillingphase,moltenplasticisinjectedintothecavityuntilthecavityisjustfilled.Asplasticflowsintothecavity,theplasticincontactwiththemouldwall quickly freezesandthiswillcreatea frozen layerofplasticbetweenthemouldandthemoltenplastic.Plate1 showshowtheflowfrontexpandsasmaterialfrombehindispushedforward.Theedgeoftheflowfrontcomesintocontactwiththemouldandfreezes.Themoleculesinthefrozen layerarethereforenothighlyorientated,andoncefrozen,theorientationwillnotchange.Plate1:MolJ.enplasticflowinsidethemouldTheredarrows showtheflowdirectionofthemoltenplastic.Thedarkbluelayersagainstthemouldwalls showthelayersoffrozenplastic.Thegreenarrows indicate thedirectionofheatflowfromthepolymermeltintothemouldwalls.Thefrozen layer gainsheatasmoremoltenplastic flowsthroughthecavity,andlosesheattothemould.Whenthefrozen layerreachesacertainthickness,equilibriumisreached.Thisnormallyhappensearlyintheinjectionmouldingprocess,afterafewtenthsofa second.Pressurization PhaseThepressurizationphasewillhappenafterthefillingphasecompletely fillsthecavityarea. At this stage, alltheflowpathswillbefilledupbymoltenplastic,theedgesand86PertanikaJ.Sci.&Techno!.SupplementVa!. 12o. 2, 2004DesignandSimulationofPlastic InjectionMouldingProcesscornersofthefillingareainthecavity maynotcontainplastic.Tocompletely filloutthegeometry,extraplasticispushedintothecavityduringthepressurization phase.Plate2 showsthedifferencebetweentheendofthefillingphase(left image)andtheendofthepressurizationphase(rightimage).oticetheunfilledcorners (insidethebluecircles)thatareleftattheendofthefilling phase.Theyellowconeindicatesthepolymerinjectionlocationandtheplasticisred.FillinR PhasePlate2:DifferencebetweenjiUing and pressurization phasePressurization PhaseCompensatingPhasePlasticmaterialhas ahighvolumetric shrinkage,formthemeltingplastic to solid,itwillshrinkageaverageof25%.Thereforeafterthepressurization phase,morematerial mustbeinjectedintothecavity tocompensatefortheplasticshrinkingafteritcools. Thisisthecompensatingphase(MoldFlowHelpFiles).Mould Basic ConstructionMoulddesignandmouldmakingcanbeconsideredthemostcritical processesoftheinjectionmouldingsystem.Thisisbecausethemoulddesignandmouldmakinghavetremendousimpactonproductivityandproductquality. Basically,thefunctionofthemouldistwo fold.Thefirst isimpartingthedesiredshapetotheplasticized polymer,thesecondis coolingtheinjectionmouldedparts.Themould,which containsoneormorecavities, consistsoftwo basic parts:A stationarymouldhalfonthesidewheretheplasticisinjectedA movinghalfontheclosingorejectorside.Theseparationofthetwo mouldsiscalledthepartingline.Themouldwilldeterminethefinalproductpropertiessuchas size, shape, dimensionandfinishing surface. Usually,themeltedplastic materialisfilledthroughthecentralfeedchannelcalledspruetothecavity.Themouldwill coincide withtheinjectionmachinecylinder nozzle.Table1isthesummarylist formouldcomponentandthefunctionrespectively.Mould DesignTostartupa newmoulddesign,thedesignershouldknowsomeimportantpoints toavoidsomemistakesbeforegoingfurtherLe.productoutlookdesign, material usage,correctshrinkageofthematerial,numberofcavitiesandselectionofthemouldbase.Making a mistakecancauseanill-fittingmouldatthefinal assemblyandalsomaketheplasticproductoutoftoleranceandberejectedbythecustomer.Fig.1 showsthemoulddesignerschart.PertanikaJ.Sci.&Techno.SupplementVo.12No.2,200487/Wong, C.T.,ShamsuddinSulaiman,NapsiahIsmail&A.M.S.HamoudaCreate amodelinCADsoftware (convertinSTL)J.l.-OpenthemodelinSelect a plastic materialPartAdvisorandsupplier.Ifa single injection locationisrequired,goontothenextstepIfmultipleinjection locations wanted, skipthenextstepandgototheoneafterIRunthegatelocatorIJ.IRuntheanalysisLCreateoneormoreIinjection locations-Lookattheanalysis result, decideifthemodelwill fill easilyandcreategoodqualityparts-Iftheresults arenotsatisfactory, goontothenextstep-Iftheresultsareacceptable, skipthenextstepandgo totheoneafterChangeoneoftheparametersandthenCreate areportonthere-analyze-.analysis result, usingtheTheseparametersare:reportgeneratorPositionornumberofinjectionlocationJ.MaterialMouldtemperatureSendthereporttotheMelttemperaturepeoplewhoneedtosee itInjection timePartgeometryFig.2:Procedure diagram for Part Advisor simulationMoldflow software.Plate5 showsthesolidmodelwithgatelocation placingontopofthemodel.Theyellowcolourconeshapeshowstheiectionlocationinthis analysis.Ininjectionandtransfermoulding,thegateisconsideredtheportionofthemouldedpiecethatallowsthemoltenresin to flowtherunnerorfromthesprueintothecavity.Thegatemaybethesamesizeandshapeastherunner,butgenerallyitismuchsmaller.Thereisanoptimumgatesize.Itshouldbelargeenoughfor suitable fillrateandsmallenoughtosealoffandpreventbackfloworoverpacking.Product Simulation ResultBefore startingthesimulationprocess,someinformationhas tobesetup,such asmaterialsupplierandmaterialgrade.Thisisnormally already setintheMoldflowdatabaseandtheuserjustselectsthespecificmaterialspecification.Table2 shows theelementused.forthis analysis:90PertanikaJ.Sci.&Techno!.SupplementVol. 12No.2,2004DesignandSimulationofPlasticInjectionMouldingProcessPlate5:Solid modelWithgate locationTABLE 2Moulding process specificationPartNameMaterialGradeMouldTemperatureMeltTemperatureMax Injection PressureTNGCLIP VERSIONABS65050deg.C235deg.C60 MPaFill TimeFill timeisthetimetakentofillupthepartinsidethecavity,itisalso to show howtheplasticmaterialflows to fillthemould.Fromthatweknowthattheshortshot(partofthemodelwhichdidnotfill)partwillbedisplayed.Fromthatresultonecanalsounderstandhowtheweld lineandairtrapwill form.Plate6 showsthematerialfillingintothemould.filTMlltAJlIII.A2D.31.,!isttlJIII.JlIPlate6:100%materials fillofplastic partConfidenceofFillTheconfidenceoffillresultdisplaystheprobabilityoftheregionwithinthecavity withplastic.Thisresultisderivedfromthepressureandtemperatureresults.Theconfidenceoffill will displayinthreecolours:green,yellow,redandtranslucent. Showingingreenwill definitely fill,inyellow maybedifficult to fillormay have qualityproblem,inredwillbedifficult to fillorwill have qualityproblemandintranslucentwillnotfill(shortshot).PertanikaJ.Sci.&Techno!.SupplementVo!.12No.2,200491Wong, C.T.,ShamsuddinSulaiman,apsiahIsmail&A.M.S.HamoudaIfthecavitydoesnotfill, somechangesmustbemadetoeitherdesign, gate location,choiceofplasticorprocessing conditions.However,toensurethefinishedpartisofgoodquality,thecavitymustalsobeadequatelypackedwith plastic.Plate7 showsconfidenceoffillinthis analysis.udd.ceotlillPlate7:ConfidenceofflUInjectionPressureThecolourateachplaceonthemodelrepresentsthepressureattheplaceonthemodel.Two colours showthehighestpressure(red)andlowest pressure (blue).Theinjectionpressurecanbeusedinconjunctionwithpressuredropresult.Forexample,evenifa sectionofaparthasanacceptablepressuredrop,the actual injection pressureinthesameareamaybetoohigh.Highinjectioncancause overpacking.Toreducethechanceofthishappening,follow these steps:1.Increasethemaximuminjection pressure2.Alterthepolymerinjection location3.Alterpartgeometry4.Select adifferentmaterialPlate8 showstheresultofinjectionpressurefrom0 MPa to 47.02Mpa.,Plate8:Injectionpressure.1UII.tII-lU1JI.lIJUlJ1.I1CUleTl2PressureDropPlate9 showsthepressuredropresult.Whentheplaceisfilled,thepressurewilldropfromtheinjectionlocationtotheendofthefilled part.Thepressuredropsresult uses92PertanikaJ.Sci.&Techno.SupplementVo. 12No.2,2004DesignandSimulationofPlasticInjectionMouldingProcessarangeofcolourstoindicatetheregionofhighest-pressuredrop(colouredred)throughtotheregionoflowestpressuredrop(colouredblue).Thepressuredropisonefactorusedtodeterminetheconfidenceoffillresult.111:,001PJ.D,Plate9:Pressure drapIMP-I .JO.0.,n.5.21.232.9.31.8U,31Jl2AirTrapsPlate10showstheairtrapsresultafteranalysis.Thesmallbluebubblesareshowingtheairtrapsintheparts. Airtrapsresultshowstheregionswherethemeltstopsataconvergenceofatleast 2 flowfrontsoratthelastpointoffill,whereabubbleofairbecomestrapped.Topreventairtrapsoccurringwhenconvergingflowfrontssurroundandtrapabubbleofair,balanceflowpathsbyeither:1.Usingflowleaders/deflectors2.Changingpartwall thickness3.ChangingpolymerinjectionlocationsPlate 10:AirtrapMouldDevelopmentMterdoingalltheMoldflowsimulationfortheproduct,moulddesignwillbeprecededbasedonthesimulationresult.Onlyonemouldbaseisusedtoproducetwodifferentplastic parts;thisisbecausealmost70%oftheplasticproductshapesaresimilar, sochangeableinsertsareusedinthis case.CoreinsertwillbeaspermanentinsertandchangethesliderandcavityinsertforTG Clip versionandTG Stick version.Plate 11showsthecavityandcoreinsertforTG ClipandStick version.PertanikaJ.Sci.&Techno.SupplementVo. 120.2,200493Wong, C.T.,ShamsuddinSulaiman,NapsiahIsmail&A.M.S.HamoudaCavity insertfor TNG stickPlate11:Cavity,cureandslider insertMouldBase SizeForthis project, three-plate type systemmouldbaseisused withpinpointgating.Thesizes forthemouldbaseare250mmx 250mIllwith FCI type, A-plate size 100mm,B-plate size 70mm,Spacerblocksize 100mmandwith striper plate(referredfrom LKM(LungKee Metal)mouldbasehandbook).Thefunctionofthestripperplateistoremovetherunnerfromtheplasticpartandtheplasticpartwillbeconsideredagoodproductwithnoneedtotouchup.Forthismouldbasejustonecavity will beinjectingeachtime,themoltenmaterialofplastic will flowthroughspruetothecavity.Aftercooling, the plastic partswillhardenandstick tothecoreandthenbeejectedbyusingtheshoulder-typeejectorpin.ThreePlateMouldThreeplatemouldsareusedinthisprojectbecausethegatingpointtoinjectthemoltenplasticissmallandtherunnersystemforathree-platemouldsitsonasecondpartingplaneparallel tothemainpartingplane.Thissecondpartingplaneallowstherunnersandspruetobeejectedwhenthemouldisopen.Inthis three-platemould,therunnerswillbeejectedseparatelyfromthecavitiesandtheplasticpartafterinjection doesnotneedtogothroughanytouchupprocess (Rosato 1986).SliderCoreSlidercoreisusedwhentheplastic partsaredesignundercutforexample, side hole,side boss, etc. Slidercoreisstationaryattachedto plate B(refertoPlate14)andtwoangularpinsareattachedto plateA.Whenthemouldopens,theangularpinwill movetheslidecorehorizontallyoutfromthemouldposition.Theamountoftheslidecoremovementwilldependontheangleandhow fartheslider movesontheangularpin.Bythetimethemouldisopened,theslidecorehas movedenoughsothattheejectorpinhasbeenfully withdrawnfromtheplastic part.CoolingSystem(Water Channel)A waterchannelistocontrolthetemperatureofthemouldsurfaceandto chillupthemoltenplasticmaterialtobecomerigid statesthateject fromthecoreside.Forthis94PertanikaJ.Sci.&Technol.SupplementVol. 12No.2,2004DesignandSimulationofPlasticInjectionMouldingProcessprojectthewaterchannelsaredesignedtobedrilledalongthelengthofcavities,coreandslider.Thecoolingsystemisvertically tothemould.Plate12showstheflowofthewaterchannelinthemouldinsert.Plate12:Water channelflowinside mould insertGatingSystemThegateistheconnectionbetweentherunnersystemandthemouldedpart.Itmustpermitenoughmaterialto flowintothemouldtofilloutthepartplusadditionalmaterial asisrequiredtoovercomethenormalthermalshrinkageofthepart.Inthisproject,pinpointgatesareused,whenthemouldisopenthepartwill automaticallyberemovedfromtherunnerandthereisnoneedtotouchupfortheplasticproduct.Plate13showsthepinpointgatesystem.Plate13:Pinpoint gatesystemCompleteMouldAssemblyPlate14showsthecompletedmouldassembly forTNGClip Version.Plates15and16showthecross-section formouldclose assemblyandopenassembly position.CAD/CAM for Mould DesignIntheplastic industry, CAD/CAM hasemergedtothepointwhereitnowshowsthepromiseofbeingoneofthemostsignificant technological advancesofthecentury.PertanikaJ.Sci.&Techno!.SupplementVo!.12No.2,200495Wong,CT.,ShamsuddinSulaiman,NapsiahIsmail&AM.S.HamoudaPlate14:CompletedmouldassemblyPlate15:Cross-sectionmouldcloseassemblyCAD/CAM isenablingthecreativeenergiesofplasticpartandmoulddesigners to bespentinproducingbetterdesignsinashortertimeperiodratherthanindoingrepetitivemoulddesign tasks.The AdvantagesofCAD/CAMTheadvantagesoftheCAD/CAMinmoulddesignare:a)CAD/CAMtechnologiesarenormallyusedforthenumericallycontrolled(C)machiningtechnologyto fabrication forthemouldsandalso its ability to createthree-dfmensionalproductmodelsinthedatabaseandtogenerateautomatically.96PertanikaJ.Sci.&Techno.SupplementVo. 12No.2,2004DesignandSimulationofPlasticInjectionMouldingProcessBottomClampPlatePlate16:Cross-sectionmquldopenassemblyb)CAD/CAMcanhelpdesigners tospeedupdesignfortheplasticpartandmoulddesign processandreducethelonglead-time.c)CAD/CAMusedintherepetitiveandroutinetasksofmouldmakingwillenhancethequalityofwork life for those skilledmouldmakersbyprovidingmOlechallengeandjobsatisfaction.d)Easyforusers toredefineforpartgeometry; thismeansitcanenhancequalityinthemoulddesignbyreducinginthenumberoferrors.ApplicationofCAD/CAM andtheMethods for Mould DesignInthis project,thetypeofCAD/CAM softwareemployedisPro/Engineer2000i.ProfMoldesign isanextensionofPro/Engineertothemouldmanufacturingenvironment,covering all aspectsofproductionmoulddesignsuchasmouldbases,runnersystemcreation,waterlines, ejector-pin holes,shrinkageandhundredsofotherfeatures.ThePlate 14formouldassemblyisusingPro/Moldesigntocreateanddesignthe mould.ProfCandPro/MFGarethemanufacturingextensionsofPro/EngineerintoC Cproductionarena,.andhave a widebreadthofcapabilities coveringfrom3 to 5 axismilling, 2and4 axis wire EDM,turning,laser, flame, etc.Afterdesigningallthemoulds,Pro/NCandPro/MFGforthemanufacturingwillplayanimportantroleagainintheprocessofcreatingthedetail drawingneededandgeneratingC toolpathstomachinetheactualmould.TheCtoolpathsarederivedfromtheproductmodeldatabase.Productpathscompletedin3-Dmodelwill be directlyextractedfromthemoulddesigndatabaseformanufacturing,forexample,coreinsertsfromthemoulddatabasethatwanttodosomemanufacturing.Before startingCAD/CAMsomeoftheimportantfeatureshave tobeconsideredlike toolfeedrate, spindlespeed,stepdepth,materialto mill,Plungerspeed,coordinatesystem,andwhatkindofendmill used.TostartCAD/CAM,dimensionofwork piece has tobedecidedfirstandthensettingthecoordinatesystem tothework piece.Thework piececoordinatemustbeofthesamesetting withthecoordinateintheCNCmachine.Thewrongsetting will cause themachinetocrashwiththeworkpiece.Decidewhatkindofmanufacturingprocess touse, forexampleprofiling,volume,pocketing, hole-makingandconventionalsurface.After selectingthemanufacturingprocess,ProfC will convertcomputercodetoPertanikaJ.Sci.&Techno!.SupplementVo!. 12No.2,200497Wong, C.T.,ShamsuddinSulaiman,NapsiahIsmail&A.M.S.Hamoudamachiningcodeby using ICAM (Intelligencecomputer-aidedmanufacturing)software.Machiningcodeslike G-codeandM-eode willbestoredintheCNCandthenthemanufacturingisrun.Plate17showsthesolidmodelsimulationbeforerunningtheactualmanufacturingandPlate18shows wire frame simulationandtheredlineinPlate 18isthetoolrunningpointtopointposition.Plate17:SolidrrwdelsimulationPlate18:Wireframe simulationPro/MFGwillcreatethedatanecessary todriveanNCmachinetool tomachineaPro/Moldesignpart.Itdoesthis by providingthetool toletthemanufacturingengineerfollow a logicalsequenceofsteps toprogressfroma designmodelto ASCII CLdatafilesthatcanbepost-processedintoNCmachinedata.TheCAD/CAM illustrationinFig.3canbasicallybesummarizedthePro/MFGprocess(Pro/MFG,RI8).DISCUSSIONANDCONCLUSIONTheconceptualdesignontheplasticpartsisbasedontheneedofthecardriver.Theplastic partsholdercasingisto placetheTouchNGocardorPLUS hi-way ticketforthedriver to have easy access toitwhenhe/shereachesthetoll.Inthisprojecttheplastic parts weredesignedintotwodifferenttypesofproductbutdesigninonechangeableinsertmouldbase.Justusingonemouldbase willreducethecostandtimeinmanufacturing.Pro/Moldesign,Pro/MFGandPro/NCfromPro/ENGINERareusedto designthemouldandfabricatetheplastic parts.Inthemould-makingindustries,accuracyandtolerancearetheimportantissues; so using CAD/CAM willenhancequalityoftheworkinthemoulddesignandreducethenumberoferrorsinmanufacturing.Fromtheanalysis simulation, Moldflow