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ID:13067660
大小:126.00 KB
页数:8页
时间:2018-07-20
《understanding selection of injection moulding machin1》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、UNDERSTANDINGSELECTIONOFINJECTIONMOULDINGMACHINEINTRODUCTIONPlasticInjectionMouldingprocessdemandsprecisecontrolofmelttemperature,meltviscosity,injectionspeed,injectionfollow-uppressure,switchoverpointfromspeedtopressure,cycletime.Itisfoundthatdifferentpolymershavedifferentcharacteristicsanddiffer
2、entlimitationsinprocessing.Shearrateandshearstressinfluencemelttemperature,viscosity,densityandflowbehaviorofpolymer.Somepolymersarehygroscopic,somepolymerhavelimitedthermallystabletimewhichisdifferentatdifferenttemperature.Suchpolymershavelimitedresidencetime.Thechangesineachparameterhasitsowninf
3、luencesonotherparameters.Hence,processcontrolbecomesveryintricate.Thiscallsforcriticalanalysisofthemachinespecificationsandcapabilitieswhileorderingthemachine.Whileselectinginjectionmouldingmachinethefollowingspecificationsarerequiredtobeevaluated.INJECTIONUNITTounderstandMaximumsweptvolumecc/max.
4、shotweightgr.calculationofmax.shotweightforamaterial.Maximummeteringstrokeinmm.dependanceofqualityofmeltforconsistancyofmoulding.Maximuminjectionspeedg/sorcc/showitensursmelttospreadthroughoutwheninfluidcondition-beforeitfreezes.Itsrelationshipwithfreezingtime.MaximuminjectionpressureKg/cm2howitov
5、ercomesresistancetoflowduringfillingand;pressurephaseonaccountofflowratioand;viscosity.MaximumInjectionPower.Kgcm/sec.howittakescareofdifficultyinfiilingforthinerwalledandhighflowratioparts.Plasticizingrateg/sorKg/hr.howitinfluencescycletime.CLAMPINGUNITTounderstandClearancebetweenTiebarsandplaten
6、sizemmxmmhowitaccomodatesmould.Maximumdaylightmmandmouldopenstrokemmitssignificanceforejectionofdeepparts.Minimummouldheightitsrelationshipwithmouldopenstrokeanddaylight.Clampingforceitsdependanceoncavitypressureandmethodtocomputecavitypressure.HYDROMOTORToubderstandTorqueKgmandrpmtorquerequiremen
7、tfor-viscosityof-melt.DRIVEPOWERPowersupplyfrquency60or50Hz.itsinfluenceonspeeds.Pump-motorrating.kWtomatchtheapplication-usageofmachine.CONTROLS·Conventional/ProportionalandCartridgevalveHydraulicControls·Electr
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