3_plastics.ppt1.ppt

TraditionalManufacturingProcesses Casting Forming Sheetmetalprocessing Cutting Joining Powder andCeramicsProcessing Plasticsprocessing Surfacetreatment PowderMetallurgy ManufacturingwithCeramics Finepowder plastic ceramic metal Joinpowderparticles heattojustbelowmeltingpoint ballsusedinball pointpensgears camscuttingtools inserts porousmetalfiltersoil impregnatedbearingspistonringsinengines Shapebycompactinginadie P M 1 PowderProduction Atomization Sprayliquidmetalusinghigh pressurewater inertgas Chemicalmethod PassCOorH2gasoverpowderedMetaloxide reduction Electrochemicalaction Solutionofmetalsalt Current Metaldepositsoncathode wateratomizer airatomizer P M 2 PowderBlending 3 PowderCompaction BlendingMixdifferentsizesofpowderhomogeneouslyAddlubricanttoimprovecompactiondielife Compaction producesgreenmold P M 4 Sintering 5 Finishing Greencompact heatedinovento70 90 ofmeltingpoint Diffusionweld Sintering 3 stageSinteringfurnace burnofflubricant sinter cooldown Finishing Coiningandsizing forgingdietoimprovedimensionalaccuracyImpregnation e g oilimpregnationforself lubricationbearingsInfiltration e g brazingofsteelpowderstoaddstrength ManufacturingwithGlass andCeramics GlassSheetmaking Rollingoperationusingmoltenglass Lenses Headlampsmanufacture Moldingprocess Glasstubesandrods Drawingprocessusingmoltenglass Bottlemanufacture Blowmolding source http www pct edu prep bm htm TraditionalManufacturingProcesses Casting Forming Sheetmetalprocessing Cutting Joining Powder andCeramicsProcessing Plasticsprocessing Surfacetreatment PlasticsHistory Generalproperties moredurable harder tough light Typicaluses automobileparts constructionmaterials Plastictypes Thermosets Examples UnsaturatedPolyesters lacquers varnishes boathulls furnitureEpoxiesandResins glues coatingofelectricalcircuits composites fiberglassinhelicopterblades boats Plastictypes Elastomers Generalproperties thesearethermosets andhaverubber likeproperties Typicaluses medicalmasks gloves rubber substitutes Examples Polyurethanes mattress cushion insulation toysSilicones surgicalgloves oxygenmasksinmedicalapplicationsjointseals Generalproperties lowmeltingpoint softer flexible Typicaluses bottles foodwrappers toys Examples Polyethylene packaging electricalinsulation milkandwaterbottles packagingfilmPolypropylene carpetfibers automotivebumpers microwavecontainers prostheticsPolyvinylchloride PVC electricalcablescover creditcards carinstrumentpanelsPolystyrene disposablespoons forks Styrofoam Acrylics PMMA polymethylmethacrylate paints fakefur plexiglassPolyamide nylon textilesandfabrics gears bushingandwashers bearingsPET polyethyleneterephthalate bottlesforacidicfoodslikejuices foodtraysPTFE polytetrafluoroethylene non stickcoating Gore Tex raincoats dentalfloss Plastictypes Thermoplastics PlasticsProcessing Extrusion PlasticsProcessing Blowmolding similartoglassblow molding PlasticsProcessing Thermoforming Sheetofplastic Heated soft Moldedusingashapeddie Vacuumthermoforming PlasticsProcessing CompressionandTransferMolding usedmostlyforthermosettingpolymersmoldisheatedandclosedusingpressureplasticflowstofillsthecavityflashmustbetrimmedbyfinishing dishes handlesforcookingpotsskis housingforhigh voltageswitchessomerubberpartslikeshoesolesandevencompositessuchasfiber reinforcedparts PlasticsProcessing CompressionandTransferMolding compressionmolding transfermolding morecomplexshapes PlasticsProcessing InjectionMolding Probablythemostcommon mostimportant mosteconomicalprocess PlasticsProcessing InjectionMolding Cycleofoperationforinjectionmolding source AVI source hk InjectionMolding geometryofthemold Basiccomponents moldpieces definethegeometryofthepart ANDsprue gates runners vents ejectionpins coolingsystem InjectionMolding 2 pieceand3 piecemolds InjectionMolding moldswithmovingcoresandside actioncams Ifthegeometryoftheparthasundercuts definition InjectionMolding designinginjectionmolds 1 moldingdirections numberofinserts camsrequired ifany2 partinglines3 partingplanes byextendingthepartinglineoutwards4 gatingdesign wheretolocatethegate s 5 multiplecavitymold fixrelativepositionsofthemultipleparts6 runners flowofplasticintothecavity7 spruelocated 8 functionalpartsofthemold ejectionsystem toejectthemoldedpart systemstoejectthesolidifiedrunners alignmentrods tokeepallmoldcomponentsaligned InjectionMolding designinginjectionmolds 1 moldingdirections numberofinserts camsrequired ifany2 partinglines3 partingplanes byextendingthepartinglineoutwards4 gatingdesign wheretolocatethegate s 5 multiplecavitymold fixrelativepositionsofthemultipleparts6 runners flowofplasticintothecavity7 spruelocated 8 functionalpartsofthemold ejectionsystem toejectthemoldedpart systemstoejectthesolidifiedrunners alignmentrods tokeepallmoldcomponentsaligned cup partingline partingplane gate Designinginjectionmolds moldinaction source Lecnotes ProfT Gutosky MIT Designinginjectionmolds typicalfeatures source www idsa mp org Designinginjectionmolds typicalfeatures Considerationsindesignofinjectionmoldedparts Thetwobiggestgeometricconcerns i properflowofplastictoallpartsofthemoldcavitybeforesolidification ii shrinkingoftheplasticresultinginsinkholes Guideline 1 maintainuniformcross sectionthicknessthroughoutthepart How useofribs gussets source GEplastics InjectionMoldingDesignGuidelines Considerationsindesignofinjectionmoldedparts Guideline 2 avoidthickcross sections source GEplastics InjectionMoldingDesignGuidelines Considerationsindesignofinjectionmoldedparts Guideline 3 gatelocationdeterminesweldlines weldlines Source http www idsa mp org proc p