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INTERNATIONALJOURNALOFMACHINETOOLSACCEPTED4MARCH2003ABSTRACTTHEUSEOFSTEREOLITHOGRAPHYSLTOOLINGALLOWSPLASTICPARTSTOBEPRODUCEDBYINJECTIONMOULDINGINAVERYSHORTTIMEDUETOTHESPEEDOFMOULDPRODUCTIONONEOFTHESUPPOSEDADVANTAGESOFTHEPROCESSISTHATITPROVIDESALOWVOLUMEOFPARTSTHATARETHESAMEASPARTSTHATWOULDBEPRODUCEDBYTHECONVENTIONALHARDTOOLINGINAFRACTIONOFTHETIMEANDCOSTHOWEVER,THISWORKDEMONSTRATESDIFFERENTRATESOFPOLYMERSHRINKAGEAREDEVELOPEDBYPARTSPRODUCEDBYSLANDCONVENTIONALTOOLINGMETHODSTHESEREVELATIONSMAYCOUNTERTHEGREATESTADVANTAGESOFTHESLINJECTIONMOULDINGTOOLINGPROCESSASTHEPARTSDONOTREPLICATETHOSETHATWOULDBEPRODUCEDBYCONVENTIONALHARDTOOLINGTHISWORKIDENTIFIESTHEDIFFERENTSHRINKAGETHATOCCURSINMOULDINGSPRODUCEDBYANSLMOULDASCOMPAREDTOTHOSEPRODUCEDFROMANALUMINIUMMOULDTHEEXPERIMENTSUTILISETWOVERYDIFFERENTTYPESOFPOLYMERSANDTWOMOULDGEOMETRIES,WHICHAREPROCESSEDINTHESAMEMANNERSOTHATTHEHEATTRANSFERCHARACTERISTICSOFTHEMOULDSAREISOLATEDASTHEONLYEXPERIMENTALVARIABLETHEWORKDEMONSTRATESHOWTHETWOMOULDMATERIALSEXHIBITVERYDIFFERENTRATESOFEXPANSIONDUETOTHETEMPERATUREPROFILESEXPERIENCEDDURINGMOULDINGTHISEXPANSIONMUSTBECOMPENSATEDFORTOESTABLISHTHETOTALAMOUNTOFSHRINKAGEINCURREDBYMOULDEDPARTSTHECOMPENSATIONISDERIVEDBYAMATHEMATICALAPPROACHANDBYMODELLINGUSINGFINITEELEMENTANALYSISBOTHTECHNIQUESDEPENDUPONKNOWLEDGEOFTHETHERMALCONDITIONSDURINGMOULDINGKNOWLEDGEOFTHESETHERMALCONDITIONSAREOBTAINEDBYREALTIMEDATAACQUISITIONANDSIMULATEDBYFEAMODELINGTHEAPPLICATIONOFTHEFINDINGSPROVIDEKNOWLEDGEOFTHECOMPLETESHRINKAGEVALUESRELATINGTOTHEMOULDMATERIALANDPOLYMERUSEDWHICHWOULDENABLETHEPRODUCTIONOFGEOMETRICALLYACCURATEPARTSKEYWORDSFINITEELEMENTANALYSISPLASTICINJECTIONMOULDINGPOLYMERSHRINKAGERAPIDTOOLINGWITHOUTEXTERNALASSISTANCEIECOOLINGBYCOMPRESSEDAIRTHESLMOULDWOULDTAKE15MINUTESTORETURNTOITSAMBIENTTEMPERATURE42INITIALSHRINKAGERESULTSTHEINITIALSHRINKAGEVALUES,CALCULATEDFROMTHEPART/MOULDMEASUREMENTS,CANBEVIEWEDINTABLE1HOWEVER,THESEFIGURESNEEDFURTHERCONSIDERATIONTOESTABLISHTHETOTALSHRINKAGETHATOCCURSTHISISEXPLAINEDINTHEFOLLOWINGSECTION43COMPENSATIONFORTHERMALEXPANSIONBYCALCULATIONBOTHOFTHEMOULDMATERIALSUSEDEXPANDWHENHEATED,ALBEITINDIFFERINGAMOUNTSTHEMEASUREMENTSTABLE1THESIZEDIFFERENCEOFPART/MOULD,INCLUDINGCOMPENSATIONFORTHERMALEXPANSIONBYCALCULATIONFEAPA66PARTMEASUREMENTABSPARTMEASUREMENTMOULDTYPEALBARSLBARALDISCSLDISCALBARSLBARALDISCSLDISCPART/MOULDDIFFERENCEH1100213272H110022611H1100212177H1100224149H1100207524H1100206474H1100207351H1100205611PART/MOULDDIFFERENCEH1100213434H1100227308H1100212339H1100226101H1100207687H1100207696H1100207514H1100207599INCLUDINGCOMPENSATIONFORTHERMALEXPANSIONBYCALCULATIONPART/MOULDDIFFERENCEH1100213841H1100227447H1100212712H1100225649H1100208097H1100207837H1100207887H1100207139INCLUDINGCOMPENSATIONFORTHERMALEXPANSIONBYFEATAKENFORSHRINKAGEMUSTBECOMPENSATEDFORBYTHEAMOUNTOFCAVITYEXPANSIONTOESTABLISHTHETRUEAMOUNTOFDIFFERENCEBETWEENMOULDANDPARTMEASUREMENTSNOTCOMPENSATINGFORTHERMALEXPANSIONCOULDLEADTOANUNDERESTIMATIONOFSHRINKAGETHATOCCURSDURINGMOULDINGTHEVALUEOBTAINEDFORSHRINKAGEHADTOBECORRECTEDBYANAMOUNTCORRESPONDINGTOTHETHERMALEXPANSIONOFTHEMOULDTHEEXPANSIONOFTHEMOULDRESULTEDINANEXPANSIONOFTHECAVITY,NOTCONTRACTIONTHISWASVERIFIEDBYPLACINGTHEMOULDINSERTSINANOVENATANOMINALTEMPERATUREOF50CFOR10MINANDTHENMEASURINGTHECAVITYINTHEAPPROPRIATEMEASUREMENTAXISSEEFIG2ALLMOULDSSHOWEDANINCREASEINCAVITYSIZE,DEMONSTRATINGANEXPANSIONOFTHECAVITYTHISWASAUTHENTICATEDFURTHERINLATERWORKSECTION445THISCORRECTIONFACTORH9004SMTOTHEPARTSHRINKAGEDUETHEMOULDEXPANSION,ISGIVENBYH9004SMAMTMH11002TA13WHEREAMLINEARCOEFFICIENTOFEXPANSIONOFTHEMOULDMATERIALIN10H110026M/M/KTMMAXIMUMMOULDTEMPERATUREDURINGINJECTIONCYCLEINCTAAMBIENTTEMPERATUREOFTHEMOULDONTHEMACHINEINCTHEVALUESUSEDWEREL50539AML50539SL5910H110026M/M/KL50539AL23810H110026M/M/K18TAL50539SL235CL50539AL235CANEXPLANATIONOFTHESEVALUESISGIVENINSECTION34TMTHESEVALUESWEREDERIVEDFROMTHETHERMALHISTORYPROFILESOFTHEMOULDSANDTHEINJECTIONPARAMETERSTHETEMPERATUREATTHEENDOFTHEINJECTIONCYCLEWASUSEDINTHECALCULATIONSASTHISWASTHEPOINTATWHICHPRESSUREAPPLICATIONTOTHEINJECTEDPOLYMERCEASEDWHENPRESS883RAHARRISETAL/INTERNATIONALJOURNALOFMACHINETOOLSMANUFACTURE432003879887UREAPPLICATIONENDED,SODIDTHEPERIODATWHICHTHESHRINKAGECOULDBEINFLUENCEDANYFURTHEREXPANSIONOFTHEMOULDAFTERTHISPERIODWOULDBEUNABLETOAFFECTTHEPARTSIZETHEDERIVATIONOFTHEVALUESISILLUSTRATEDINFIG4THEMAXIMUMTEMPERATURETMATTHEENDOFTHEINJECTIONCYCLEFOREACHMOULDTYPEWEREL50539SLDISC5746CL50539SLBAR4437CL50539ALDISCBAR3039CTHESAMEMAXIMUMTEMPERATUREWASEXPERIENCEDBYBOTHTHEALUMINIUMMOULDSTHISMAXIMUMTEMPERATUREWASREACHEDBEFORETHEENDOFTHEINJECTIONCYCLETHETEMPERATUREINTHESTEREOLITHOGRAPHYMOULDSCONTINUEDTORISEFORALONGPERIODAFTERCOMPLETIONOFTHEINJECTIONCYCLEDIFFERENTMAXIMUMTEMPERATURESWEREEXPERIENCEDINTHESLDISCBARMOULDSDUETOTHEDIFFERENTTIMESOFTHEINJECTIONCYCLEREQUIREDBYTHEIRDIFFERENTPARTVOLUMETHEREFORE,THECALCULATIONFORTHERMALEXPANSIONFOREACHMOULDTYPEWASASFOLLOWSSLDISCMOULD5910H1100265746H11002235200364MM/M0200364SLBARMOULD5910H1100264447H11002235123133MM/M0123133ALDISCBARMOULD2381063039H11002235016422MM/M0016422THEEXTRAAMOUNTOFSHRINKAGEDETERMINEDBYCALCULATINGTHEEXPANSIONOFTHEMOULDWASINCORPORATEDINTOTHEPERCENTAGESHRINKAGEOFTHEMEASUREDPARTSTOREVEALTHECOMPENSATEDTOTALSHRINKAGETHESEVALUESARESHOWNINTABLE1HOWEVER,THESECALCULATIONSWERESLIGHTLYSIMPLIFIEDANASSUMPTIONWASMADETHATTHEWHOLEMOULDWASATTHETEMPERATUREDETERMINEDBYTHEDATAACQUISITIONFORTOOLTEMPERATURESANDASSUCHEQUALFIG4THERMALCONDITIONSINTHEMOULDSDURINGINJECTIONCYCLEEXPANSIONWASEXPERIENCEDTHROUGHOUTINREALITYTHEINCREASEINTEMPERATUREWASLOCALISEDAROUNDTHEMOULDINGCAVITYFURTHERWORKWASREQUIREDTOPROVEWHETHERANYDIFFERINGEXPANSIONOFTHEMOULDCAVITYOCCURREDDUETOTHETEMPERATUREDISTRIBUTIONANDTOASSESSANYSUCHEFFECTSONTHECOMPENSATIONVALUESUSED44COMPENSATIONFORTHERMALEXPANSIONBYFINITEELEMENTANALYSISFINITEELEMENTANALYSISFEAWASUSEDTOMODELTHEMOULDEXPANSIONDUETOTHELOCALISEDHEATINGCAUSEDBYTHEHOTPOLYMERCONTAINEDWITHINTHECAVITYTHEFEASOFTWAREPACKAGEUSEDINTHISWORKWASALGORTWOFORMSOFFEAANALYSISFROMALGORWEREUSEDFIRSTLY,ATRANSIENTTHERMALANALYSISWASCONDUCTEDINORDERTODETERMINETHETEMPERATUREDISTRIBUTIONINTHEMOULDTHENALINEARELASTICANALYSISWASPERFORMEDUSINGTHETEMPERATUREDISTRIBUTIONRESULTSTODETERMINETHERESULTINGEXPANSIONOFTHEMOULDCAVITY441FEAMODELLINGSTAGE1CREATIONOFMODELTHEFEAWORKBEGANWITHTHECREATIONOFTHEREQUIREDMODELSANDFEAMESHINORDERTOREDUCESOLUTIONTIME,ONEQUARTEROFTHEFULLMOULDWASCREATED,DUETOTHEQUARTERLYSYMMETRICALNATUREOFEACHOFTHESPECIMENSGAUGELENGTHTHISISSHOWNINFIG5THEMODELWASEXTRUDEDSUCHTHATTHEMESHSPACINGBETWEENEACHNODEWAS05MMINTHEIMMEDIATEREGIONBENEATHTHEMOULDINGCAVITY4MMDEEPASTHESEARETHEELEMENTSOFINTERESTWHENEVALUATINGTHECAVITYEXPANSIONTHISWASCONDUCTEDTOENSURETHATANODEWASATTHEEQUIVALENTPOINTTOTHETHERMOCOUPLEINTHEEXPERIMENTS,FROMWHICHTHECRITICALTIMEDEPENDANTTEMPERATURESWEREDERIVEDSEESECTION33AFTERTHISTHEMESHSPACINGFORTHERESTOFTHEMODELWAS10MMINORDERTOACHIEVEASHORTERANALYSISTIME442FEAMODELLINGSTAGE2ALLOCATIONOFMATERIALPROPERTIESTHEMATERIALSWEREASSUMEDTOBEHOMOGENEOUSANDISOTROPICWITHCONSTANTMATERIALPROPERTIESINDEPENDENTOFTEMPERATURETHEVALUESARELISTEDINTABLE2443FEAMODELLINGSTAGE3TRANSIENTTHERMALANALYSISTRANSIENTTHERMALANALYSISREFERSTOATHERMALCONDITIONWHERETEMPERATUREISAFUNCTIONOFTIMETHISANALYSISTYPEWASRELEVANTTOTHECONDITIONSTHATOCCURREDWITHINTHEMOULDSDURINGTHEEXPERIMENTSTHEHEATWASSUPPLIEDBYTHEINJECTEDPOLYMERWHICHTRANSFERREDITSENERGYHEATINTOTHESURROUNDINGMOULDMATERIALTHISENERGYWASNOTLIMITLESSANDTHEPOLYMERCORRESPONDEDBYREDUCINGINTEMPERATUREASTHEHEATWASTRANSFERREDINTOTHELOWERTEMPERATUREMOULD884RAHARRISETAL/INTERNATIONALJOURNALOFMACHINETOOLSMANUFACTURE432003879887FIG5FEAMODELSECTIONOFBARDISCMOULDSTABLE2MATERIALVALUESUSEDINFEAFOREPOXY,ALUMINIUMPOLYMERAEPOXYSIUNITSREFERENCESOURCERDENSITY1250KG/M322KTHERMALCONDUCTIVITY019W/MK22CPSPECIFICHEATCAPACITY10467J/KGC22EMODULUSOFELASTICITY26109N/M222NPOISSONSRATIO03522ATHERMALCOEFFICIENTOFEXPANSION5910H110026/C18ALUMINIUMR2720KG/M323K170W/MOK23CP880J/KGC23E689109N/M223N0323A2310H110026/C23POLYMERR1145KG/M322K02962W/MK22CP16257J/KGC22E026109N/M2AAN03522A59OR2310H110026/CA18OR23ATHEVALUEOFEFORTHEPOLYMERWASANOMINALLOWVALUETOREDUCERESTRAINTTHEVALUEOFAINTHEPOLYMERWASMADETHESAMEASTHEMOULDMATERIALTOPREVENTINTERFERENCETHEUSEOFSUCHVALUESINBOTHCASESWASTOENSURETHATTHEPRESENCEOFTHEPOLYMERDIDNOTINFLUENCETHEEXPANSIONOFTHECAVITYINTHESIMULATIONTOCONDUCTTHETRANSIENTTHERMALANALYSIS,CERTAINASSUMPTIONSWEREMADEL50539THEPOLYMERWASALLINITIALLYAT270CANDWASINPERFECTCONTACTWITHTHEMOULDATALLTIMESL50539THEREWASNOTHERMALRESISTANCEBETWEENTHEPLASTICANDTHEMOULDL50539THEMOULDMATERIALWASALLINITIALLYAT235CTHECRITICALTIMEDEPENDANTTEMPERATURESSEEFIG4ATTHEPOSITIONSEQUIVALENTTOTHERMOCOUPLEPLACEMENTINTHEEXPERIMENTSWEREPLOTTEDFROMTHEFEARESULTSANDTHECORRECTSTEPINTHESOLUTIONNOTEDFROMTHISTEMPERATUREDISTRIBUTIONITWASPOSSIBLETOINVESTIGATETHEREACTIONOFTHEMODELEXPANSIONTOACHOSENCONDITIONTEMPERATUREATAPREIDENTIFIEDTIMESTEPBYPERFORMINGALINEARELASTICANALYSIS885RAHARRISETAL/INTERNATIONALJOURNALOFMACHINETOOLSMANUFACTURE432003879887444FEAMODELLINGSTAGE4LINEARELASTICANALYSISTHEMODELSWEREFULLYRESTRAINEDONTHEPLANESOFSYMMETRY,ONTHEBASISOFWHICHTHEFEAMODELSWEREDEVISEDSHOWNINFIG5ANDTHEPARTINGPLANEOFTHEMOULDINSERTSNOFURTHERRESTRAINTSWEREAPPLIEDALLOWINGFREEEXPANSIONTHELATTERPOINTMAYATFIRSTSEEMALITTLEODDASTHEMOULDINSERTWASCONTAINEDINASTEELPOCKETWITHINTHEINJECTIONMOULDINGBOLSTERHOWEVERITHASBEENALREADYSHOWNTHATEVENINOPTIMUMCONDITIONSTHEMAXIMUMPOSSIBLEEXPANSIONOFTHEWHOLEINSERTCOULDBEJUST025MMINANYONEDIRECTIONTHISAMOUNTOFEXPANSIONCOULDOCCURFREELYDUETOTHECLEARANCEREQUIREDTOENABLEFITTINGANDREMOVALOFTHEINSERTSINTHEBOLSTERPOCKETTHEPLANESOFRESTRAINTAREILLUSTRATEDINFIG6445FEAMODELLINGSTAGE5RESULTSAFTERTHELINEARELASTICANALYSISWASPERFORMEDTHEMOVEMENTSTHERMALEXPANSIONOFTHEMODELREPRESENTINGTHEPLANESOFMEASUREMENTSEEFIG2WEREDETERMINEDBYINTERROGATINGTHEDISPLACEMENTVECTORSOFTHENODESREPRESENTINGTHECAVITYEDGEANEXAMPLEOFTHISISILLUSTRATEDINFIG7FROMTHESEDISPLACEMENTSANAVERAGEMOVEMENTEXPANSIONWASDETERMINEDINEACHCASETHERESULTSDEMONSTRATEDANOUTWARDSEXPANSIONOFTHECAVITYTODETERMINETHETOTALMOULDEXPANSIONOVERTHEMEASUREMENTAXIS,THEAVERAGEFIGUREDERIVEDFROMTHEDISPLACEMENTVECTORSWASDOUBLEDTOINCLUDEAXIALEXPANSIONINTHEOPPOSITEDIRECTION,ASONLYHALFOFTHEMEASUREMENTAXISWASMODELLEDTHERESULTSOFTHESEEXPANSIONVALUESONTOTALPARTSHRINKAGEAREDETAILEDINTABLE15DISCUSSIONITCANBESEENFROMTHERESULTSTABLE1THATALLOWINGFORTHERMALCOMPENSATIONREVEALSHIGHERVALUESOFFIG6PLANESOFRESTRAINTONBARDISCFEAMODELSFIG7INTERROGATIONOFDISPLACEMENTVECTORSINFEARESULTSTOESTABLISHAMOUNTOFEXPANSIONEXAMPLESHOWSALBARSHRINKAGEINALLPOLYMER/TOOLCOMBINATIONS,ALBEITATDIFFERINGSCALESSOMEOFTHEVALUESREVEALEDQUITEDIFFERENTSHRINKAGEVALUESWHENTHEMOULDEXPANSIONWASINCORPORATEDTHEFEAVALUESGAVEAGOODCOMPARISONWITHTHOSEDERIVEDFROMTHECALCULATIONSTHISGAVECONFIDENCETHATTHEMETHODUSEDDIDGIVEANACCURATEASSESSMENTOFTHEMOULDEXPANSIONANDTHERESULTINGTOTALSHRINKAGEOFTHEPARTSITSHOULDBENOTEDTHATTHEFEAMETHODISAN886RAHARRISETAL/INTERNATIONALJOURNALOFMACHINETOOLSMANUFACTURE432003879887APPROXIMATESOLUTIONANDRELIESONTHEACCURACYOFTHEMODEL,MESHDENSITY,MATERIALPROPERTIES,SURFACECONTACTRESISTANCEANDPHYSICALRESTRAINTSALTHOUGHMANYOFTHEFIGURESUSEDINTHEFEAWEREDEFINITIVEASTHEYWEREPRODUCEDFROMREALPRACTICE,SOMEWERETHERESULTOFASSUMPTIONSTHATHADTOBEMADEWHENCOMPENSATIONFORTHERMALEXPANSIONISINCLUDED,SEVERALTHEMESINTHEPARTSHRINKAGERESULTSFROMTHEEXPERIMENTALDATAWEREREVEALEDTHESEINCLUDE51SHRINKAGEDIRECTIONTHECRYSTALLINEPOLYMERPA66DEMONSTRATEDSLIGHTLYGREATERSHRINKAGEDIFFERENCES7MOREINTHEPOLYMERFLOWDIRECTIONBARSPECIMENASOPPOSEDTOTHEDIRECTIONPERPENDICULARTOPOLYMERFLOWDISCSPECIMENTHISWASALSOSHOWNWITHTHEAMORPHOUSABSPARTSBUTTOALESSERDEGREE3MORETHESECHARACTERISTICSARETYPICALOFALLINJECTIONMOULDEDPARTS,WITHCRYSTALLINEPARTSBEINGMORESUSCEPTIBLETOANISOTROPYDIRECTIONALDIFFERENCESDUETOTHEFLOWDIRECTIONCAUSINGGREATERALIGNMENTOFCHAINSWITHINTHEPOLYMER1952SHRINKAGEACCORDINGTOMOULDMATERIALPA66THERESULTSSHOWTHATTHESHRINKAGETHATOCCURREDINPA66PARTSFROMTHESLMOULDSOFBOTHGEOMETRIESWASDOUBLETHATINCURREDBYTHECOMPARATIVEPARTSFROMTHEALMOULDSANEXPECTEDSHRINKAGERANGEFORPA66IS12220THEPARTSFROMTHEALMOULDSDEMONSTRATEDSHRINKAGEJUSTABOVETHEMINIMUMAMOUNTEXPECTED,WHILETHEPARTSFROMTHESLMOULDSINCURREDSHRINKAGEABOVETHEMAXIMUMINTHEEXPECTEDSHRINKAGERANGEALSOTHERANGEOFPARTOFSIZESMEASUREDWEREMUCHGREATERTHANTHOSEEXPERIENCEDINTHEABSPARTSPA66PARTMEASUREMENTSDIFFEREDINARANGEOF035MMASCOMPAREDTO018MMFORTHEABSPARTSTHISISATYPICALCHARACTERISTICOFCRYSTALLINEPOLYMERSWHICHAREMOREDIFFICULTTOHOLDPARTTOLERANCES,ASCOMPAREDTOAMORPHOUSPOLYMERS2153SHRINKAGEACCORDINGTOMOULDMATERIALABSTHERESULTSSHOWTHATTHESHRINKAGEOFTHEABSPARTSISLARGELYUNAFFECTEDBYTHEMOULDMATERIALUSEDASHRINKAGEOF076WASINCURREDBYALLABSPARTSINTHEEXPERIMENTSANEXPECTEDSHRINKAGERANGEFORABSIS0506206CONCLUSIONSTHISWORKHASDEFINEDTHATDOUBLETHEAMOUNTOFSHRINKAGEOCCURREDINPA66ACRYSTALLINEPOLYMERWHENINJECTIONMOULDEDINANSLTOOL,ASCOMPAREDTOANALTOOLINTHESAMEEXPERIMENTALCONDITIONSABSANAMORPHOUSPOLYMERDEMONSTRATEDNOSUCHDIFFERENCESTHEIMPORTANCEOFCOMPENSATINGFORTHERMALEXPANSIONOFTHEMOULDINTHECALCULATIONOFSHRINKAGEHASBEENDEMONSTRATEDTHISISCRITICALINDETERMININGABSOLUTESHRINKAGEVALUESINPLASTICTOOLS,WHICHEXPANDMORETHANMETALTOOLSNEGLECTINGTHEMOULDEXPANSIONINPLASTICTOOLSWOULDLEADTOSIGNIFICANTERRORINDETERMININGTHEABSOLUTEPARTSHRINKAGETHEESTABLISHMENTOFDIFFERINGPARTSHRINKAGEINCRYSTALLINEPOLYMERSEXPOSESAFLAWINTHEUSEOFSHRINKAGECOMPENSATIONFACTORSSUPPLIEDBYMANUFACTURERSTHISWORKHASSHOWNTHATTHESHRINKAGEOFCRYSTALLINEPOLYMERSISDEPENDANTUPONPROCESSCONDITIONSWHICHAREVARIABLESUPPLIEDSHRINKAGEFACTORSWOULDBESPECIFICONLYTOTHECONDITIONSUNDERWHICHTHETESTPIECESWEREPRODUCEDTHUS,TRADITIONALSHRINKAGEFACTORSAREINSUFFICIENTNOTONLYINTHEUSEOFSLTOOLS,BUTALSOANYOTHERTECHNIQUESWHERETHEREISANYSIGNIFICANTPROCESSVARIATIONFROMTHENORMITHASBEENSHOWNTHATTHESHRINKAGEOFANAMORPHOUSPOLYMERWASUNAFFECTEDBYTHECOOLINGCONDITIONSWHICHWEREIMPOSEDBYMOULDMATERIALTYPECONSEQUENTLY,WHEREPOSSIBLE,ITISRECOMMENDEDTHATAMORPHOUSPOLYMERSAREUSEDINPREFERENCETOCRYSTALLINEALTERNATIVESWHENUSINGSLMOULDSREFERENCES1PDHILTON,PFJACOBS,RAPIDTOOLINGTECHNOLOGIESANDINDUSTRIALAPPLICATIONS,MARCELDEKKER,20002TLUCK,FBAUMANN,UBARALDI,COMPARISONOFDOWNSTREAMTECHNIQUESFORFUNCTIONALANDTECHNICALPROTOTYPESFASTTOOLINGWITHRP,PROCEEDINGSOFFOURTHEUROPEANRPCONFERENCE,1315JUNE,1995,BELGRIATE,ITALY,PP2472603JESCHLEXPERIENCESWITHPHOTOPOLYMERINSERTSFORINJECTIONMOULDING,EUROPEANSTEREOLITHOGRAPHYUSERSGROUPMEETING,25NOVEMBER,FLORENCE,ITALY,19974RAHARRISDIRECTAIMTOOLINGRAPIDPROTOTYPINGTOOLINGSTATEOFTHEINDUSTRYANNUALWORLDWIDEPROGRESSREPORT,WOHLERSREPORT2002,PUBLISHEDBYWOHLERSASSOCIATESINC,USA,PART3TOOLING,P70,20025ASCHULTHESS,BSTEINMANN,MHOFMANN,CIBATOOLSLEPOXYRESINSANDSOMENEWAPPLICATIONSPROCEEDINGSOFTHE1996NORTHAMERICANSTEREOLITHOGRAPHYUSERSGROUPMEETING,1014MARCH,SANDIEGO,CA,19966MDAMLE,SMEHTA,RMALLOY,SMCCARTHY,EFFECTOFFIBREORIENTATIONONTHEMECHANICALPROPERTIESOFANINJECTIONMOLDEDPARTANDASTEREOLITHOGRAPHYINSERTMOLDEDPARTPROCEEDINGSOFTHESOCIETYOFPLASTICSENGINEERSSPEANNUALTECHNICALCONFERENCEANTEC,ATLANTA,GA,PP584588,19987DAVELARDE,MJYEAGLEY,LINEARSHRINKAGEDIFFERENCESININJECTIONMOULDEDPARTS,PLASTICSENGINEERING,THESOCIETYOFPLASTICSENGINEERS,DECEMBER2000,PP6064,20008PGIPSON,PGRELLE,BSALAMON,THEEFFECTSOFPROCESSCONDITIONS,NOMINALWALLTHICKNESS,ANDFLOWLENGTHONTHESHRINKAGECHARACTERISTICSOFINJECTIONMOLDEDPOLYPROPYLENE,THEJOURNALOFINJECTIONMOLDINGTECHNOLOGY3319991171259PPATEL,EFFECTOFPROCESSINGCONDITIONSONTHESHRINKAGEAND887RAHARRISETAL/INTERNATIONALJOURNALOFMACHINETOOLSMANUFACTURE432003879887CRYSTALLINITYOFINJECTIONMOULDEDPARTS,PROCEEDINGSOFTHESOCIETYOFPLASTICSENGINEERSSPEANNUALTECHNICALCONFERENCEANTEC,TORONTO,CANADA,PP36323635,199710DTURSI,SPBISTANY,PROCESSANDTOOLINGFACTORSAFFECTINGSINKMARKSFORAMORPHOUSANDCRYSTALLINERESINS,JOURNALOFINJECTIO
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