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1、HOME??>?Technicalsupport?>?Moldingtechnology?>???MoldingtechnologyforVECTRASafetyPredryingSelectionofMoldingMachineMoldingConditionsUseofRegrindSelectionofMoldingMachineMoldDesigning1Safety1.1SafetyPrecautionsThereisnodangerinmoldingVectraTMsolongasthegeneral
2、safetyrulesofmoldingoperationareobserved.However,likeallotherplastics,VectraTMproducesdecomposedsubstanceswhenheatedtoaveryhightemperature.Ifventilationisinadequate,suchdecomposedsubstancesarebuiltuptocausehazardousconditionstohealth.So,suitableventilationisr
3、ecommended.Donotraisethepolymertemperatureover350forVectraTMofA,BandCgradesand370forEgradesinordertopreventthermaldecomposition,gasemissionandpressurebuildupinthecylinder.Thesetemperaturesaremuchhigherthanthegivenmoldingconditionsthatitisnormallyunnecessaryto
4、heatthematerialatsuchtemperatures.Whenmoldingisinterruptedforashorttime,itispossibletoleavethematerialatthemoldingtemperature,butwhenrestarting,suchamaterialmustbethoroughlypurged.Whenmoldingisinterruptedforlongerthan30minutes,lowerthetemperature50belowthemol
5、dingtemperature.Beforefeedingpelletsorstartingthescrew,allowsufficienttimeforcylinderheating,orwaituntilthetemperaturereachesthepoint10belowthemoldingtemperatureofeachgrade.Operatorsmustwearprotectivegoggles(especiallywhenpurging).Wearhandgloveswhenhandlingah
6、otmold.Whenthemachineisstopped,withdrawtheinjectionunittokeepawayfromthemoldtopreventsolidificationofthematerialinthenozzlesection.1.2StartingandStoppingtheMoldingMachineandExchangingtheMoldingMaterial1.2.1StoppingtheMoldingMachineAfterpurgingVectraTM,andwhil
7、eretainingtheVectraTMmoldingtemperature,thecylindershouldbepurgedwitharesinwiththesamemoldingtemperatureandgoodthermalstability.(Polypropylene,high-densitypolyethyleneoracrylictypepurgingmaterialsonthemarketarerecommended.)IfVectraTMistobesubsequentlymolded,t
8、hecylindercanbepurgedwithVectraTM.(Confirmthemoldingtemperaturerangesofthegrades.)1.2.2StartingtheMoldingMachineInstartingupamachinecontaininganotherresinthatisstablewithintheVectraTMmold