ConformalCoolingMoldfor“VenturiCup”PrecisionADMandMeletPlasticsInc.

MoldDesign:JeremySparling,P.Eng.DesignAnalysis:MatthewTessier,P.Eng.AdditiveManufacturing:JaredKozub,P.Eng.Report:AlanScarth

March 19th, 2017

Brief:

Awarpingdefectwasreportedintheproductionofa“VenturiCup”partmanufacturedbyMeletPlasticsInc.foruseinanAGCO-AmityJVairseeder.Thecustomerrequestedareductioninthewarpingseeninthelargerectangularsectionofthepart.Proposedalterationsincludedchangesinmaterial,wallthicknessandcoolanttemperature,aswellasanoptimizedmoldforcoolingproducedbyPrecisionADMusingadditivemanufacturingmethods.Theuseoftheoptimizedmoldtogetherwithadecreaseinwallthicknessresultedinawarpagereductionof42%;anoverallwarpagereductionof54%wasachievedwithallotheralterationsincluded.

ConformalCoolingOverview:

Oneofthelargestfactorscontributingtothedeformationofmoldedplasticpartsisthelackofuniformheatdistributionthroughoutthemold;differentareasoftheTinalpartcoolatdifferentratescreatinginternalstressesanddeformations.Usingconventionalmolddesign,coolantchannelsarerequiredtobedrilledasaseparateoperation,andarethusrestrictedtoapathofconnectingstraightlines.Thisrestrictionisthecauseofnon-uniformheatdistributionthatcausespartdeformation.Additivemanufacturingmethodscanbeusedtocreateamoldfeaturingacoolantchannelthatfollowsthecontoursofthemold.Thisdrasticallyimprovestheheatdistributionduringcooling,andeliminatestheneedtodrillthecoolingchannels.

March 19th, 2017

Figure1:OriginalParts Figure2:ImprovedParts

ImpactofRespectiveInputs: TheinputsidentiTiedasfactorsthatreducedwarpingareasfollows:-MaterialChange:

ThematerialusedwaschangedfromRhetechGC15P200-01UVtoRhetechS26282.01.ItwasidentiTiedbythesupplierashavingsimilarphysicalpropertiesbutlesspronetowarping.Thismaterialchangealoneresultedina3%warpagereduction,butwhenpairedwiththeconformalcoolingmoldandcoolantalterationthereductionwas7%.

-ConformalCoolingandWallthickness: The3DprintedmoldinsertmanufacturedbyPrecisionADMandareductioninwallthicknessfortheTinalpart(from.110”to.080”).Theseinputsbothalteredthemoldgeometryandasaresulttheimpactofeachcouldnotbeevaluatedindividually.Togethertheycreateda42%reductioninwarpageusingtheoriginalmaterialanda44%reductionusingthenewmaterial.

-CoolantTemperature: Differentcoolanttemperatureswereusedindifferentpartsofthemoldratherthanoneuniformtemperaturethroughout.ThisselectiveapplicationofcoolantcouldonlybeconductedusingtheConformalCoolinginsert,andreducedthewarpage9%furtherusingthepreviousmaterial.Thisincreasedto15%usingthenewmaterial.

March 19th, 2017

Figure3:Previouslyusedmoldwithstraightcoolantchannels

Figure4:Printedmoldinsertwithconformalcoolantchannel

Results:

Thecumulativeeffectofallalterationsmadeintheproductionof“VenturiCup”partswasa54%reductioninwarpagefromtheoriginalparts.Whenviewedasanindependentvariable(withtheexceptionofwallthicknessalterations),theconformalcoolinginsertprintedbyPrecisionADMproduceda42%reductioninwarpage.Thisapplicationofadditivemanufacturingshowcasesthecomplexsubsurfacegeometriesthatarepossibleusingthemethod.WhileincreasingthequalityoftheTinalproduct,thisoneoffpartalsoeliminatestheneedtodrillcoolantchannelsafterthemoldhasbeenformed.ResultsandCADmodelsobtainedfromthisprojectweresuppliedbyMeletPlasticInc.

March 19th, 2017