注塑成型常见问题

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1、MoldingdefectsInjectionmoldingisacomplextechnologywithpossibleproductionproblems.Theycaneitherbecausedbydefectsinthemoldsormoreoftenbypartprocessing(molding)MoldingDefectsAlternativenameDescriptionsCausesBlisterBlisteringRaisedorlayeredzoneonsurfaceofthepartToolormaterial

2、istoohot,oftencausedbyalackofcoolingaroundthetoolorafaultyheaterBurnmarksAirBurn/GasBurn/DieselingBlackorbrownburntareasonthepartlocatedatfurthestpointsfromgateorwhereairistrappedToollacksventing,injectionspeedistoohighColorstreaks(US)Colourstreaks(UK)Localizedchangeofcol

3、or/colourMasterbatchisn'tmixingproperly,orthematerialhasrunoutandit'sstartingtocomethroughasnaturalonly.Previouscoloredmaterial"dragging"innozzleorcheckvalve.DelaminationThinmicalikelayersformedinpartwallContaminationofthemateriale.g.PPmixedwithABS,verydangerousiftheparti

4、sbeingusedforasafetycriticalapplicationasthematerialhasverylittlestrengthwhendelaminatedasthematerialscannotbondFlashBurrsExcessmaterialinthinlayerexceedingnormalpartgeometryMoldisoverpackedorpartinglineonthetoolisdamaged,toomuchinjectionspeed/materialinjected,clampingfor

5、cetoolow.Canalsobecausedbydirtandcontaminantsaroundtoolingsurfaces.EmbeddedcontaminatesEmbeddedparticulatesForeignparticle(burntmaterialorother)embeddedinthepartParticlesonthetoolsurface,contaminatedmaterialorforeigndebrisinthebarrel,ortoomuchshearheatburningthematerialpr

6、iortoinjectionFlowmarksFlowlinesDirectionally"offtone"wavylinesorpatternsInjectionspeedstooslow(theplastichascooleddowntoomuchduringinjection,injectionspeedsmustbesetasfastasyoucangetawaywithatalltimes)JettingDeformedpartbyturbulentflowofmaterialPoortooldesign,gatepositio

7、norrunner.Injectionspeedsettoohigh.KnitLinesWeldlinesSmalllinesonthebacksideofcorepinsorwindowsinpartsthatlooklikejustlines.Causedbythemelt-frontflowingaroundanobjectstandingproudinaplasticpartaswellasattheendoffillwherethemelt-frontcomestogetheragain.Canbeminimizedorelim

8、inatedwithamold-flowstudywhenthemoldisindesignphase.Oncethemoldismadeandthegateisplacedonecanonl