【管理資料】注射成型基本原理簡(jiǎn)介(important)講義匯編

注射成型基本原理簡(jiǎn)介(important)講義.注射成型基本原理簡(jiǎn)介(important)講義.目錄塑膠特性簡(jiǎn)介成型基本原理成型常見(jiàn)不良及分析目錄塑膠特性簡(jiǎn)介材料塑料(高分子)熱固性熱塑性工程通用無(wú)定型結(jié)晶性無(wú)定型結(jié)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(wú)定型結(jié)晶性無(wú)定型結(jié)晶塑膠分子結(jié)構(gòu)InjectionMoldingPlastic塑膠分子結(jié)構(gòu)InjectionMoldingPlastiRaiseTemperatureofPolymerAddingheatincreasesspacebetweenmolecularchainsbutcrystallinestructurepreventsflow.ModelofCrystallinePolymersRigidSolidSoftSolidFlowsEasilyTGTMInjectionMoldingProcess固態(tài)難於流動(dòng)較易流動(dòng)RaiseTemperatureofPolymerAdInjectionMoldingProcessModelofAmorphousPolymersAddingHeatIncreasesSpace外熱提供空間BetweenMolecularChains在分子鏈之間RaiseTemperatureofPolymer

TGLocked固態(tài)EntanglementsStiffFlow難于流動(dòng)EasierFlow較易流動(dòng)InjectionMoldingProcessModelInjectionMoldingVariablesMeltTemperature熔融溫度35302520151050.030 .060 .090 .120 .150 .180 .210 .240WallThicknessinInches壁厚(In)MeltFlow(in.)LEXAN?101550degF.101@600deg.FIncreasedMeltTemperatureyieldsincreasedFlow.提高熔融溫度導(dǎo)致增加流動(dòng)However,TooHighaMeltTemperatureMayCauseDegradation.但,過(guò)高熔融溫度造成降解InjectionMoldingVariablesMelInjectionMoldingMaterialThermoplasticsandDegradation熱塑性塑料和降解Degradation降解TemperatureTime時(shí)間InjectionMoldingMaterialTherInjectionMoldingBarrelUnitTheReciprocatingScrew(Filling)ThroatHeatingCoilsNozzleHopperBarrelForce,TorqueFromInjectionUnit料筒組件回轉(zhuǎn)式螺桿噴嘴加熱料斗加料口料筒來(lái)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InjectionMoldingBarrelUnit(FInjectionMoldingBarrelUnitTheReciprocatingScrewScrewRotationFeedsandShearsMaterialIntoaMelt.MeltCollectsIntoFrontofBarrel,ForcingScrewBackShotRotationandBackPressure出量通過(guò)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InjectionMoldingBarrelUnitScInjectionMoldingEquipmentBarrelUnitTheReciprocatingScrewShotInjectionPressure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(guò)程InjectionMoldingEquipmentBarInjectionFlow熔融流動(dòng)InjectionMoldingProcessInjectionFlowInjectionMoldinInjectionMoldingVariablesInjectionSpeed100010010100 1000 10000LEXAN?141@644degFLEXAN?141@608degFLEXAN?141@572degFApparentViscosity(Pa/s)ShearRate(1/s)InjectionSpeedaffectstheviscosityofthemoltenmaterial.注射速度表觀粘度剪切速率注射速度影響熔體粘度InjectionMoldingVariablesInjInjectionMoldingVariablesInjectionPressureProfileHydraulicPressureTimeFillTimeScrewRunTimeBackPressurePeakInjectionPressurePressureAppliedbyInjectionRamtoForcethePlasticFromtheBarreltotheMold.注射壓力曲線注射壓力峰值液壓壓力填充時(shí)間InjectionMoldingVariablesInj壓縮保壓保壓PackingPressureCushion(3~5mm)緩沖墊BarrelUnitTheReciprocatingScrewInjectionMoldingEquipment模腔填滿塑膠后,繼續(xù)施加於模腔塑膠上的注射壓力.壓縮保壓保壓PackingPressureCushionInjectionMoldingVariablesCushionCushion(3~5mm)Materialremaininginbarrelwhentheejectionphaseiscompleted.注過(guò)程結(jié)束后，殘于料筒前端的熔體Theinjectionmoldingprocessshouldallowacushiontoprovidesufficientpackingpressureinthemold緩沖墊注過(guò)程必須要有緩沖墊以保證有效的保壓緩沖墊InjectionMoldingVariablesCus

InjectionMoldingvariablesBarrelUnitTheReciprocatingScrew冷卻固化加料產(chǎn)品冷卻固化而脫模后又不致於發(fā)生變形.InjectionMoldingvariablesBaInjectionMoldingProcessPartCoolingandSolidificationHotMeltCooledMoldSolidPart制件冷卻和固化熱熔體溫度較低的模具固化的制件InjectionMoldingProcessPart來(lái)源：機(jī)器停機(jī)時(shí)間過(guò)長(zhǎng)機(jī)器長(zhǎng)時(shí)間不用未清干凈料筒噴嘴/止逆閥不良不合適螺桿類型模具在澆口和流道上有死角材料塑膠粒中雜質(zhì)其它樹(shù)脂降解來(lái)自料筒壁面降解物次料/受污染原料其它生產(chǎn)/操作環(huán)境注塑加工參數(shù)黑點(diǎn)(blackpoints)InjectionMoldingNonGoodParts來(lái)源：材料黑點(diǎn)(blackpoints)Injection診斷:注射速度太快澆口太小澆口位置不當(dāng)澆口太長(zhǎng)模具過(guò)冷料溫過(guò)低噴嘴有滴垂噴射痕(flowmarks)是熔融材料流動(dòng)的痕跡,以澆口為中心而呈現(xiàn)的條紋模樣.InjectionMoldingNonGoodParts診斷:噴射痕(flowmarks)InjectionMo診斷:產(chǎn)品脫模角度不夠模具排氣不良保壓過(guò)大頂針過(guò)少或太小頂針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(xiàn)白色痕跡.InjectionMoldingNonGoodParts頂白診斷:InjectionMoldingNonGood診斷:不正確的進(jìn)料注射壓力和速度過(guò)低注射時(shí)間太短止回閥有問(wèn)題.模具排氣不良模溫過(guò)低料溫過(guò)低或料熔體粘度太高是熔融塑料未完全流遍成型空間(模穴的各個(gè)角落之現(xiàn)象.InjectionMoldingNonGoodParts充填不足(shotshort)診斷:InjectionMoldingNonGood診斷:機(jī)器止回閥問(wèn)題注射速度過(guò)快背壓過(guò)大模具排氣不良模溫過(guò)高摩擦燒焦檢查澆口及主流道大小塑膠原料降解成形品表面因材料過(guò)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(xiàn)象.InjectionMoldingNonGoodParts燒焦(burnmarks)診斷:成形品表面因材料過(guò)熱所致的變色及成型品的銳角部份或肋的診斷:無(wú)足夠的材料或較厚肋注射壓力過(guò)低射膠時(shí)間太短機(jī)器融膠能力不足模溫太高澆口過(guò)小流道過(guò)長(zhǎng)產(chǎn)品肋/壁厚比不當(dāng)澆口位置不當(dāng)模具排氣不良成型品表面產(chǎn)生凹陷的現(xiàn)象.是體積收縮所致,通常見(jiàn)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(chǎn)生凹陷的現(xiàn)象.是體積收縮所致,通常見(jiàn)於肉診斷:材料降解(料筒有熱點(diǎn),材料在噴嘴處有死角)注射壓力或速度過(guò)低或過(guò)高背壓過(guò)低在澆口,機(jī)器噴嘴或熱流道摩擦燒焦料溫過(guò)高在塑膠粒中有污染過(guò)多水分銀條是在成型品表面或表面附近,沿材料流動(dòng)方向,呈現(xiàn)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(dòng)方向,呈現(xiàn)的銀診斷:注射壓力太低塑化太快不正確進(jìn)料在料斗進(jìn)料中夾帶空氣模具排氣不良模溫過(guò)低熔料過(guò)熱止回閥功能不足夠熔融塑料中有水份,揮發(fā)性氣體於成型過(guò)程進(jìn)入成型品部而殘留的空洞現(xiàn)象.InjectionMoldingNonGoodParts氣泡(bubbles&voids)診斷:熔融塑料中有水份,揮發(fā)性氣體於成型過(guò)程進(jìn)入成型品部而殘謝謝!!!謝謝!!!人有了知識(shí)，就會(huì)具備各種分析能力，明辨是非的能力。所以我們要勤懇讀