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1、GE Plastics,INJECTION MOLDING,e,注射模塑技术,Injection Molding Introduction,注塑之优点,Injection Molding Introduction,GOOD PART,Material 材料,Tooling 模具,Processing 工艺,Design 设计,好产品,Equipment 设备,Injection Molding Equipment,MACHINE SHOT SIZE 机器注射容量 Part Weight = 40 - 80 % of Machine Shot Size 制件重量 = 40 - 80 % 机器注射
2、容量 Optimal Part Weight = 40 60 % of Machine Shot Size 制件重量 = 40- 60 % 机器注射容量,Injection Molding Equipment,材料选择 投影面积 产品设计(制件厚度,流动长度) 注射压力,Injection Molding Clamping,Injection Molding Equipment,Screw Type Machines Are Recommended 推荐采用的螺杆类型,Injection Molding Equipment,Metering 计量,Feed 进料,Screw and Cylin
3、der Design 螺杆和料筒设计,hf,hm,L/D长径比 = 20:1(18:124:1) Compression Ratio压缩比 =2.5:1(2:12.5:1) Cylinder bi-metallic for Abrasion Resistance 双金属料筒,Transition 过渡,L,D,Injection Molding Equipment,往复式reciprocating 螺杆头结构 检查环类型: 止回环,熔融树脂流过 开放检查环,检查环关闭, 防止在 注塑过程中料的回流,建议采用止逆阀,Injection Molding Equipment,Standard Cyl
4、inder Nozzles 标准料筒喷嘴,Heating Band 加热环,Cylinder Bore料筒主体,To Mold,Provides Mechanical and Thermal Connection From Hot Cylinder to Colder Mold 提供从热的料筒到相对冷的模具的机械和热连接,到模具,Injection Molding,Sprue Bushing 主流道衬套,Nozzle 喷嘴,Radius 半径,Orifice 主流道孔口,段道长度最大5mm 射嘴开口: 4.769.53 mm 主流道衬套孔口要比喷嘴口径大0.81mm 尽可能地短,Tooling
5、模具,Injection Molding tooling,Material flows only through the molten portion of runner,Outer layer of material chills on contact with steel surface,Runners Flow,外层接触模具冷却固化 熔体由内层向前流动, 即实际有效流动面积要小于流道截面面积.,流道半径微小的增加就可以很大程度地增加流量, 并相应地减小压力降,Q = 流量 P = 压力降 R = 浇口半径 N = 粘度 L = 流动距离,Q =,8n L,Q Proportional t
6、o R4,n R P,4,Runner,圆形 效率最好,梯形 可接受的,半圆 不好的,PL,Runners Design,Runner design recommended profiles,RD,RD,RD W D 3.24.83.2 4.86.44.8 6.48.06.4 8.011.08.0 9.512.79.5,Equivalent Round Runner,Design Alternative,Runners Design,Runner design trapezoidal profiles,W,D,W,Runners Design,Runner sizing recommendat
7、ions: 平衡的配置是最好的 一级流道: 圆形或梯形是最好的 Length 250mm or longer:9.5mm diameter Length 75mm to 250mm:7.9mm diameter Length under 75mm:6.5mm diameter 二级流道: 6.5mm diameter minimum,Sprue Puller,REVERSE TAPER BEST,Z PULLER GOOD,GROOVE TROUBLE- SOME,SUCKER PIN NOT RECOMMENDED,Tooling Runners,RESTRICTIVE,PREFERRED,
8、Tooling Runners,流动方向,冷料井,Tooling Runners,冷料井,流道直径:D,1.5 X D,Unbalanced System,A,A,A,A,B,B,B,B,Tooling Runners,Balanced System,Tooling Runners,浇口定位要考虑的基本因素有：制件设计、流动和产品最终使用要求。应牢记下面的几点，以此作为一般指南。 需要多浇口的大制件，应该有位置足够紧密的浇口，以减少压力损失。这样做可使树脂流动前缘交汇点的冷却最小化，从而提供较好的熔合线强度。应选择合适的浇口尺寸，以使树脂的充填有一个合理的压力和速度。 浇口过渡段长度应保持尽可
9、能的短。 撞流浇口将有助于保证流入的流体直接对着模腔壁或型芯，从而可以避免漩纹。 为避免夹气，来自浇口树脂流，应将空气导向排气槽。 浇口位置应确定好，以便让树脂从厚壁部位流向薄壁部位；让熔合线最小化；并且远离冲击和应力区。 要使漩蚊、放射斑和浇口白晕减至最少，浇口应与流道有一个合适的角度(下图). 直接浇注到装饰性表面，会引起表面缺陷。,Gate design,Gating,侧浇口的高度应为80100%的壁厚, 宽度应为浇口深度的2倍,侧浇口,0.5mm Land Length,1.272.53mm,900,点浇口,Gating,Molded Part,Sprue,Parting Line,加
10、设倒圆改善流动,Knock Out Pin,Tunnel Gate,Tooling Gating,300,450,1mm(min.),R1025,R,Gate,Cashew Gate,Tooling Gating,25,2.5D,A Hot Runner System,Runners Heated Runners,Hot Runner Benefits Faster Cycles - 15-20% Faster Eliminates Material Waste - No Sprues or Runners Improves Part Quality - Less Stress - Bette
11、r Appearance,Runners Heated Runners,Differences in Design Philosophy,Runners Heated Runners,Runners Heated Runners,Smaller,Larger,Faster Colour Change Shorter Residence Time,Lower Shear Lower Pressure Drop,Melt Channel Sizing,Runners Heated Runners,Heating the Manifold,Runners Heated Runners,Parting
12、 Line,Depth 0.0350.075mm,Gate,2.5mm,Note Step,6mm(min.),0.40.75mm,Tooling Venting,2550mm,Clearance Around Knockout,.0025,Ejector Pin,Tooling Venting,Molding Process 成型工艺,Injection Molding,使用合适的设备,正确的条件对材料进行预干燥,Dry Environment -30C dew point,Air Flow Rate 1 cfm/hourly lb of resin used,Temperature 120
13、C,Time 4 hrs+,Injection Molding Predry,Processing 工艺,Start-up: 开机:,Purge with the Correct Material 用正确料清洗 Use Correct Processing Conditions 采用正确加工参数,Injection Molding Process,Recommended Purge Materials 推荐清洗料,PolymerPurge Material 聚合物 清洗料 Cycolac /Cycoloy PMMA, PS, SAN Noryl PS, PMMA Lexan PMMA, HDP
14、E Valox PS, HDPE Ultem LEXAN, HDPE(Extrusion Grade) Supec HDPE,Injection Molding Process,Injection Molding Process,Important Process Variables 重要加工参数,Melt Temperature 熔融温度 Mold Temperature 模具温度 Temperature Profiles 温度曲线 Residence Time 停留时间 Injection Speed 注射速度 Injection Pressure 注射压力 Pack Pressure 保
15、压 Clamp Tonnage 锁模力 Cushion 缓冲料垫,Injection Molding Process,Model of Amorphous Polymers,Raise Temperature of Polymer,T,G,Locked 固态 Entanglements,Stiff Flow 难于流动,Easier Flow 较易流动,Injection Molding Variables,Melt Temperature 熔融温度,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,Injection Molding
