塑料在包装中的应用.ppt

1,PlasticinPackaging,Lesson7,第7课塑料在包装中的应用,2,1.Whatelementsareinthemolecule?2.Whatsize(molecularweight)isthemolecule?3.Isthemoleculepolarornon-polar?4.Whatshapeisthemolecule?5.Whatisitsthermalhistory?6.Whatisitsmechanicalhistory?,PolymerPropertiesDependOn:,3,DeformationandThermalHistory,Roomtemperaturedeformationispermanent.,PlasticsstretchedataboutTgandcooledslowlyareheatstable.,PlasticsstretchedataboutTgandcooledquicklyhave“memory”andwillshrinkifreheated.,4,PlasticatingExtruder,Fig.10.2,5,CastFilmandSheetExtrusion,Fig.10.4,6,Three-LayerCoextrusion,Fig.10.9,7,ExtrusionCastFilmLineLayout,Fig.10.5,8,MachineDirectionOrientation,Fig.10.8,9,CrossDirectionOrientation,Fig.10.8,10,Blown-filmDieCross-Section,Fig.10.6,Thedieisoftenrotatedtopreventgaugebands,11,Three-layerExtrusionBlowMold,Cut-awayview,material1,material2,material3,filmbubble,12,BlownFilmLineWithSlitter,Fig.10.7,13,BlownFilmLineShowingDie&Bubble,14,InjectionMoldingExtruders,Fig.10.10,15,InjectionMoldingMachine,Extruderbarrel,Feedhopper,Moldlocation,Extrudersaresizedbytheirclampingcapacity,16,Three-PlateInjectionMold,Fig.10.12,17,Three-PlateInjectionMold,18,PartsWithAttachedRunners,Thedistancebetweenthesprueandthegatemustbeexactlythesameforeverycavity,19,PlasticShrinkageandSinkMarks,Fig.10.16,MostcommonlycanbeseenoppositeclosurethreadsSinkmarksovercupflangesupportribscancausesealingproblems,20,MoldingUndercuts,Fig.10.15,21,InjectionMoldingUndercuts,22,Bottle-MakingTerminology,Finish:ThatpartofabottleorjarthatacceptstheclosureParison:AninitialshapethatwillbeexpandedintoabottleorjarinasecondstepPreform:Describestheparisonwhenusinginjectionblow-moldingMoyle:Thepinch-offtrimpiecefromanextrusionblow-moldedbottle,23,ExtrusionBlowMold,Fig.10.20,24,ExtrusionBlowMold,R,Neck-ringinsertCoolingwaterportsCut-offinsert,1,2,3,1,3,2,25,ExtrusionBlowMolding(EBM),Fig.10.18,26,Injection-BlowMoldingMachine,27,UntrimmedEBMPPBottle,R,3.Tailorpinch-offtrim,1.Finishtrim,2.Handleknock-out,1,2,3,28,ParisonExpansion&WallThickness,Figure10.24,29,Fig.10.22,ParisonsandBottleWallThickness,30,ProgrammableParisons,Fig.10.23,31,ExamplesofCoextrudedBottles,1&2Reducedpigmentoninnerlayer3ThreelayerbottlewithU.V.barriercentrallayer,1,2,3,R,32,Injection-BlowMolding(IBM),Fig.10.23,33,Injection-BlowMoldingMachine,Fig.10.27,34,Injection-BlowMoldingMachine,35,IBMPreformsandContainer,R,36,Injection-StretchBlowMolding(ISBM),Fig.10.28,37,ISBMPreformsandSodaBottles,R,38,PropertiesImposedbyMolding,R,39,EBMandIBMCompared,toolingonemoldsettwomoldsetsmoldcavitiescommonly2or312andmorepossiblesecondaryoperationstrimandregrindnotrimorregrindfinishtolerancesacceptableprecisionuniquefinishdesignslimitedpossiblehandlewarecommoncomplexthin-wallcontainersyesnocomplexm