塑料注射模拟和设计模制过程.pdf

PertanikaJ.Sci.thisisbecausealmost70%oftheplasticproductshapesaresimilar, so changeableinsertsareusedinthis case.Coreinsertwillbeaspermanentinsertand changethesliderandcavityinsertforTG Clip versionandTG Stick version.Plate 11 showsthecavityandcoreinsertforTG ClipandStick version. PertanikaJ.Sci. thismeansitcanenhancequalityinthe moulddesignbyreducinginthenumberoferrors. ApplicationofCAD/CAM andtheMethods for Mould Design Inthis project,thetypeofCAD/CAM softwareemployedisPro/Engineer2000i.Prof Moldesign isanextensionofPro/Engineertothemouldmanufacturingenvironment, covering all aspectsofproductionmoulddesignsuchasmouldbases,runnersystem creation,waterlines, ejector-pin holes,shrinkageandhundredsofotherfeatures.The Plate 14formouldassemblyisusingPro/Moldesigntocreateanddesignthe mould. ProfCandPro/MFGarethemanufacturingextensionsofPro/EngineerintoC C productionarena,.andhave a widebreadthofcapabilities coveringfrom3 to 5 axis milling, 2and4 axis wire EDM,turning,laser, flame, etc. Afterdesigningallthemoulds,Pro/NCandPro/MFGforthemanufacturingwill playanimportantroleagainintheprocessofcreatingthedetail drawingneededand generatingC toolpathstomachinetheactualmould.TheCtoolpathsarederived fromtheproductmodeldatabase.Productpathscompletedin3-Dmodelwill be directly extractedfromthemoulddesigndatabaseformanufacturing,forexample,coreinserts fromthemoulddatabasethatwanttodosomemanufacturing.Before startingCAD/ CAMsomeoftheimportantfeatureshave tobeconsideredlike toolfeedrate, spindle speed,stepdepth,materialto mill,Plungerspeed,coordinatesystem,andwhatkindof endmill used. TostartCAD/CAM,dimensionofwork piece has tobedecidedfirstandthensetting thecoordinatesystem tothework piece.Thework piececoordinatemustbeofthesame setting withthecoordinateintheCNCmachine.Thewrongsetting will cause the machinetocrashwiththeworkpiece.Decidewhatkindofmanufacturingprocess to use, forexampleprofiling,volume,pocketing, hole-makingandconventionalsurface. After selectingthemanufacturingprocess,ProfC will convertcomputercodeto PertanikaJ.Sci. so using CAD/CAM willenhance qualityoftheworkinthemoulddesignandreducethenumberoferrorsin manufacturing. Fromtheanalysis simulation, Moldflow provides sufficientinformationresults such as fill time, injectionpressureandpressuredrop.With this result, userscanavoidthe defectoftheplasticinactualinjectionsuchas sink mark, hesitation,airtraps,and overpacking.Theanalysis will alsohelpthemoulddesignerto design aperfectmould withminimummodificationsanditwill alsoreducethemouldsetuptime. With this analysisandsimulationitwillhelptoreducetimeandcost. 98 PertanikaJ.Sci.&Techno!.SupplementVa!.12No.2,2004 DesignandSimulationofPlasticInjectionMouldingProcess Pr I Design Model II Workpiece I -1ManufacturingModelj.- / MachineTools (Workcells) I FixtureSetupSetUpManufacturingDatabase 1 Tools .1 SetUpOperation II 1 o/MFG 1 Define NCSequences 1 1I 1 I CreateCLData Files I 1 ProduceIn- Process Model II Post-Process 1 1 I Drive NCMachineTool I Fig.3:Summarizes the Pro/MFG process REFERENCES FRADos,J.1976.Plastic Engineering Handbook (TheSocietyojthe Plastic Industry).Fourthedition. Van NostRandReinholeCompany. MoldflowHelpFiles. CAMPBELL,P.D.Q. 1996.Plastic Component Design.First edition. New York,USA:Industrial Press Inc. Pro/MFGandPro/NC-CHECKUsers guide, Release 18. ROSATO,D.Y. 1986.Injection Mol