注射成型基本原理简介(important)解读.ppt

注射成型基本原理簡介 注塑成型是一种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. 注塑過程包括預塑,計量,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. 注塑工藝參數的選擇和調整及原料,模具,設備對制品質量將產生直接影響. 目錄 塑膠特性簡介 成型基本原理 成型常見不良及分析 Injection Molding Process Model of Amorphous Polymers Injection Molding Variables Injection Molding Material Injection Molding Barrel Unit The Reciprocating Screw Injection Molding Barrel Unit The Reciprocating Screw Injection Molding Equipment Barrel Unit The Reciprocating Screw Injection Molding Variables Injection Molding Variables Injection Molding Variables Injection Molding Process * * 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 PC ABS MPPO PEI PPS PET POM PA PMMAPS PVC PE PP Injection Molding Plastic 塑料類型 塑膠分子結構 Injection Molding Plastic Raise Temperature of Polymer Adding heat increases space between molecular chains but crystalline structure prevents flow. Model of Crystalline Polymers Rigid Solid Soft Solid Flows Easily T G T M Injection Molding Process 固態 難於流動 較易流動 Adding Heat Increases Space 外热提供空间 Between Molecular Chains 在分子链之间 Raise Temperature of Polymer T G Locked 固态 Entanglements Stiff Flow 难于流动 Easier Flow 较易流动 Melt Temperature 熔融温度 35 30 25 20 15 10 5 0 .030 .060 .090 .120 .150 .180 .210 .240 Wall Thickness in Inches壁厚(In) M e l t F l o w (in.) LEXAN?101 550 deg F. 101 @ 600 deg. F Increased Melt Temperature yields increased Flow.提高熔融温度导致增加流动 However, Too High a Melt Temperature May Cause Degradation.但,过高熔融温度造成降解 Thermoplastics and Degradation 热塑性塑料和降解 Degradation 降解 T e m p e r a t u r e Time 时间 (Filling) Throat Heating Coils Nozzle Hopper Barrel Force, Torque From Injection Unit 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 Screw Rotation Feeds and Shears Material Into a Melt. Melt Collects Into Front of Barrel, Forcing Screw Back Shot Rotation and Back Pressure 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 Shot Injection Pressure 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 Injection Flow 熔融流動 Injection Molding Process Injection Speed