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1、注射成型基本原理簡介注塑成型是一種注射兼模塑的成型的方法,又稱注射成型.是塑料成型加工最普通也是最早的成型方法.注塑過程包括預(yù)塑,計(jì)量,注射,充模,泠卻定型等過程,得到一定幾何形狀和精度的塑件制品.注塑工藝參數(shù)的選擇和調(diào)整及原料,模具,設(shè)備對(duì)制品質(zhì)量將產(chǎn)生直接影響.前言目錄塑膠特性簡介成型基本原理成型常見不良及分析材料塑料(高分子)熱固性熱塑性工程通用無定型結(jié)晶性無定型結(jié)晶性PCABSMPPOPEIPPSPETPOMPAPMMAPSPVCPEPPInjectionMoldingPlastic塑料類型塑膠分子結(jié)構(gòu)InjectionMoldingPlasticRaiseT
2、emperatureofPolymerAddingheatincreasesspacebetweenmolecularchainsbutcrystallinestructurepreventsflow.ModelofCrystallinePolymersRigidSolidSoftSolidFlowsEasilyTGTMInjectionMoldingProcess固態(tài)難於流動(dòng)較易流動(dòng)InjectionMoldingProcessModelofAmorphousPolymersAddingHeatIncreasesSpace外熱提供空間BetweenMolecular
3、Chains在分子鏈之間RaiseTemperatureofPolymerTGLocked固態(tài)EntanglementsStiffFlow難于流動(dòng)EasierFlow較易流動(dòng)InjectionMoldingVariablesMeltTemperature熔融溫度35302520151050.030.060.090.120.150.180.210.240WallThicknessinInches壁厚(In)MeltFlow(in.)LEXAN?101550degF.101@600deg.FIncreasedMeltTemperatureyieldsincreasedFl
4、ow.提高熔融溫度導(dǎo)致增加流動(dòng)However,TooHighaMeltTemperatureMayCauseDegradation.但,過高熔融溫度造成降解InjectionMoldingMaterialThermoplasticsandDegradation熱塑性塑料和降解Degradation降解TemperatureTime時(shí)間InjectionMoldingBarrelUnitTheReciprocatingScrew(Filling)ThroatHeatingCoilsNozzleHopperBarrelForce,TorqueFromInjectionUn
5、it料筒組件回轉(zhuǎn)式螺桿噴嘴加熱料斗加料口料筒來自注塑單元的力和力矩計(jì)量區(qū)熔融區(qū)加料區(qū)Screw螺桿InjectionMoldingBarrelUnitTheReciprocatingScrewScrewRotationFeedsandShearsMaterialIntoaMelt.MeltCollectsIntoFrontofBarrel,ForcingScrewBackShotRotationandBackPressure出量通過螺桿回轉(zhuǎn)，熔體聚集于料筒前部，反作用力使螺桿后退。回轉(zhuǎn)力矩和背壓熔化混合InjectionMoldingEquipmentBarrelUn
6、itTheReciprocatingScrewShotInjectionPressure注射壓力流動(dòng)射出在一定壓力,速度下熔體從噴嘴流道澆口型腔的充填成型過程InjectionFlow熔融流動(dòng)InjectionMoldingProcessInjectionMoldingVariablesInjectionSpeed100010010100100010000LEXAN?141@644degFLEXAN?141@608degFLEXAN?141@572degFApparentViscosity(Pa/s)ShearRate(1/s)InjectionSpeedaffect
7、stheviscosityofthemoltenmaterial.注射速度表觀粘度剪切速率注射速度影響熔體粘度InjectionMoldingVariablesInjectionPressureProfileHydraulicPressureTimeFillTimeScrewRunTimeBackPressurePeakInjectionPressurePressureAppliedbyInjectionRamtoForcethePlasticFromtheBarreltotheMold.注射壓力曲線注射壓力峰值液壓壓力填充時(shí)間壓縮保壓保壓Packi
