【管理资料】注射成型基本原理简介(important)讲义汇编

注射成型基本原理简介(important)讲义.注射成型基本原理简介(important)讲义.目錄塑膠特性簡介成型基本原理成型常見不良及分析目錄塑膠特性簡介材料塑料(高分子)熱固性熱塑性工程通用無定型結晶性無定型結晶性PCABSMPPOPEIPPSPETPOMPAPMMAPSPVCPEPPInjectionMoldingPlastic塑料類型材料塑料(高分子)熱固性熱塑性工程通用無定型結晶性無定型結晶塑膠分子結構InjectionMoldingPlastic塑膠分子結構InjectionMoldingPlastiRaiseTemperatureofPolymerAddingheatincreasesspacebetweenmolecularchainsbutcrystallinestructurepreventsflow.ModelofCrystallinePolymersRigidSolidSoftSolidFlowsEasilyTGTMInjectionMoldingProcess固態難於流動較易流動RaiseTemperatureofPolymerAdInjectionMoldingProcessModelofAmorphousPolymersAddingHeatIncreasesSpace外热提供空间BetweenMolecularChains在分子链之间RaiseTemperatureofPolymer

TGLocked固态EntanglementsStiffFlow难于流动EasierFlow较易流动InjectionMoldingProcessModelInjectionMoldingVariablesMeltTemperature熔融温度35302520151050.030 .060 .090 .120 .150 .180 .210 .240WallThicknessinInches壁厚(In)MeltFlow(in.)LEXAN?101550degF.101@600deg.FIncreasedMeltTemperatureyieldsincreasedFlow.提高熔融温度导致增加流动However,TooHighaMeltTemperatureMayCauseDegradation.但,过高熔融温度造成降解InjectionMoldingVariablesMelInjectionMoldingMaterialThermoplasticsandDegradation热塑性塑料和降解Degradation降解TemperatureTime时间InjectionMoldingMaterialTherInjectionMoldingBarrelUnitTheReciprocatingScrew(Filling)ThroatHeatingCoilsNozzleHopperBarrelForce,TorqueFromInjectionUnit料筒组件回转式螺杆喷嘴加热料斗加料口料筒来自注塑单元的力和力矩計量區熔融區加料區Screw螺杆InjectionMoldingBarrelUnit(FInjectionMoldingBarrelUnitTheReciprocatingScrewScrewRotationFeedsandShearsMaterialIntoaMelt.MeltCollectsIntoFrontofBarrel,ForcingScrewBackShotRotationandBackPressure出量通过螺杆回转，熔体聚集于料筒前部，反作用力使螺杆后退。回转力矩和背压熔化混合InjectionMoldingBarrelUnitScInjectionMoldingEquipmentBarrelUnitTheReciprocatingScrewShotInjectionPressure注射压力流動射出在一定壓力,速度下熔體從噴嘴流道澆口型腔的充填成型過程InjectionMoldingEquipmentBarInjectionFlow熔融流動InjectionMoldingProcessInjectionFlowInjectionMoldinInjectionMoldingVariablesInjectionSpeed100010010100 1000 10000LEXAN?141@644degFLEXAN?141@608degFLEXAN?141@572degFApparentViscosity(Pa/s)ShearRate(1/s)InjectionSpeedaffectstheviscosityofthemoltenmaterial.注射速度表观粘度剪切速率注射速度影响熔体粘度InjectionMoldingVariablesInjInjectionMoldingVariablesInjectionPressureProfileHydraulicPressureTimeFillTimeScrewRunTimeBackPressurePeakInjectionPressurePressureAppliedbyInjectionRamtoForcethePlasticFromtheBarreltotheMold.注射压力曲线注射压力峰值液压压力填充时间InjectionMoldingVariablesInj壓縮保壓保压PackingPressureCushion(3~5mm)缓冲垫BarrelUnitTheReciprocatingScrewInjectionMoldingEquipment模腔填滿塑膠后,繼續施加於模腔塑膠上的注射壓力.壓縮保壓保压PackingPressureCushionInjectionMoldingVariablesCushionCushion(3~5mm)Materialremaininginbarrelwhentheejectionphaseiscompleted.注过程结束后，残于料筒前端的熔体Theinjectionmoldingprocessshouldallowacushiontoprovidesufficientpackingpressureinthemold缓冲垫注过程必须要有缓冲垫以保证有效的保压缓冲垫InjectionMoldingVariablesCus

InjectionMoldingvariablesBarrelUnitTheReciprocatingScrew冷卻固化加料產品冷卻固化而脫模后又不致於發生變形.InjectionMoldingvariablesBaInjectionMoldingProcessPartCoolingandSolidificationHotMeltCooledMoldSolidPart制件冷却和固化热熔体温度较低的模具固化的制件InjectionMoldingProcessPart来源：机器停机时间过长机器长时间不用未清干净料筒喷嘴/止逆阀不良不合适螺杆类型模具在浇口和流道上有死角材料塑胶粒中杂质其它树脂降解来自料筒壁面降解物次料/受污染原料其它生产/操作环境注塑加工参数黑點(blackpoints)InjectionMoldingNonGoodParts来源：材料黑點(blackpoints)Injection診斷:注射速度太快浇口太小浇口位置不當浇口太长模具过冷料温过低喷嘴有滴垂噴射痕(flowmarks)是熔融材料流動的痕跡,以澆口為中心而呈現的條紋模樣.InjectionMoldingNonGoodParts診斷:噴射痕(flowmarks)InjectionMo診斷:產品脱模角度不夠模具排氣不良保压过大顶针过少或太小顶针粘住制品頂針頂出力不平衡成型品脫模之際,因頂出銷的頂力或成型品倒鉤位之阻力,該部呈現白色痕跡.InjectionMoldingNonGoodParts頂白診斷:InjectionMoldingNonGood診斷:不正确的进料注射压力和速度过低注射时间太短止回阀有問題.模具排气不良模温过低料温过低或料熔体粘度太高是熔融塑料未完全流遍成型空間(模穴的各個角落之現象.InjectionMoldingNonGoodParts充填不足(shotshort)診斷:InjectionMoldingNonGood診斷:机器止回阀问题注射速度过快背压过大模具排气不良模溫過高摩擦烧焦检查澆口及主流道大小塑膠原料降解成形品表面因材料過熱所致的變色及成型品的銳角部份或肋的前端等材料焦黑的現象.InjectionMoldingNonGoodParts燒焦(burnmarks)診斷:成形品表面因材料過熱所致的變色及成型品的銳角部份或肋的診斷:无足够的材料或较厚肋注射压力过低射胶时间太短机器融胶能力不足模温太高浇口过小流道过长產品肋/壁厚比不當浇口位置不當模具排气不良成型品表面產生凹陷的現象.是體積收縮所致,通常見於肉厚部分,肋或凸出的背面,直接澆口肉厚不均的部份.InjectionMoldingNonGoodParts收縮(sinkmarks)診斷:成型品表面產生凹陷的現象.是體積收縮所致,通常見於肉診斷:材料降解(料筒有热点,材料在喷嘴处有死角)注射压力或速度过低或过高背压过低在浇口,机器喷嘴或热流道摩擦烧焦料温过高在塑胶粒中有污染过多水分銀條是在成型品表面或表面附近,沿材料流動方向,呈現的銀白色條紋.InjectionMoldingNonGoodParts銀條(sliverstreaks)診斷:銀條是在成型品表面或表面附近,沿材料流動方向,呈現的銀診斷:注射压力太低塑化太快不正确进料在料斗进料中夹带空气模具排气不良模温过低熔料过热止回阀功能不足够熔融塑料中有水份,揮發性氣體於成型過程進入成型品部而殘留的空洞現象.InjectionMoldingNonGoodParts氣泡(bubbles&voids)診斷:熔融塑料中有水份,揮發性氣體於成型過程進入成型品部而殘謝謝!!!謝謝!!!人有了知识，就会具备各种分析能力，明辨是非的能力。所以我们要勤恳读