注塑成型技术.ppt

1、,INJECTION MOLDING,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 % 机器注射容量 Optimal Pa

2、rt Weight = 40 60 % of Machine Shot Size 制件重量 = 40- 60 % 机器注射容量,Injection Molding Equipment,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 Cylinder 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 =

3、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 Cylinder Nozzles 标准料筒喷嘴,Heating Band 加热环,Cylinder Bore料筒主体,To Mold,Provides Mechanical a

4、nd 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模具,Injection Molding tooling,Runner,Use Adequate Runners (Full Round) 6 to 10 mm,熔体由内

5、层向前流动,外层接触模具冷却固化,Runner Flow,流道: 平衡的配置是最好的 重要点- 全圆形或梯形的流道 10mm 250mm 8 mm 75 - 250mm 6 mm 75mm,Runner,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 to R4,n R P,4,Runner,Runners Design,效率最好,较好,避免使用,PL,Tooling Runners,Sprue Puller,REVERSE TAPER BEST,Z

6、 PULLER GOOD,GROOVE TROUBLE- SOME,SUCKER PIN NOT RECOMMENDED,Tooling Runners,RESTRICTIVE,PREFERRED,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

7、，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8010

8、0%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,VENTING,Tooling Venting,Parting Line,Depth 0.0350.075mm,Gate,2.5mm,Note Step,6mm(min.)

9、,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 120C,Time 4 hrs+,Injection Molding Predry,Processing 工艺,St

10、art-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, HDPE Valox PS, HDPE Ultem LEXAN, HDPE(Extrusion Grade) Sup

11、ec 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 保压 Clamp Tonnage 锁模力 Cushion 缓冲料垫,Injection Molding Proc

12、ess,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

13、度造成降解,Injection Molding Material,Thermoplastics and Degradation 热塑性塑料和降解,How is heat added to the polymer? 外热如何作用于高分子材料,Electrical Heat: 电加热 Heater Bands 加热带 Mechanical Heat 机械热 Screw Speed 螺杆速度 Back Pressure 背压 Injection Pressure / Speed 注射速度/压力,ProductMelt Temperature (0 C) CYCOLAC 220-260 LEXAN 2

14、70-320 NORYL 240-320 VALOX 235-275 ULTEM 340-440 CYCOLOY 240-280 XENOY 240-280 SUPEC 305-330 GELOY 195-220,Injection Molding Process,产品类别 熔体温度,Injection Molding,Barrel Unit The Reciprocating Screw,Screw Rotation Feeds and Shears Material Into a Melt. Melt Collects Into Front of Barrel, Forcing Screw

15、 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,150,100,50,25,50,75,125,150,100,Screw Dia in mm,RPM,SCREW SPEED Suggestions,推荐螺杆转速,螺杆直径,转速,Injection Molding,建议的螺杆转速是根据直径而确定的。 螺杆的最佳O.D.（外径）线速度为：每秒8英寸(202.4 mm). RPM = 每秒8英寸（202.4mm）的最佳线速度60/螺杆直径3.14. 例如：螺杆直径为3英寸（75.9mm）。那么

16、，3(螺杆直径)3.1416 =9.248,再被每秒8英寸（202.4mm）(最佳线速度)60 来除=51 RPM,即为螺杆转速。,Injection Molding,Injection Molding Equipment,Barrel Unit The Reciprocating Screw,Melt Required to Fill Mold Ready for Injection,Shot,Injection Pressure,注射压力,将要注入模具内的熔体,Injection Molding Equipment,Barrel Unit The Reciprocating Screw,S

17、crew Pushes Forward: Inject,Cushion,Packing Pressure,缓冲垫,保压,注射,Injection Molding Variables,Injection Speed,1000 100 10,Injection Speed affects the viscosity of the molten material.,注射速度,表观粘度,剪切速率,注射速度影响熔体粘度,Injection Molding Variables,注射压力曲线,注射压力峰值,液压压力,填充时间,Machine Downtime,停机2小时以下时,建议将料管温度降低56degC

18、. 停机28小时时,建议将料管温度降低至170degC. 停机超过8小时的,建议将料管清洗干净,且停止加热. 对于玻纤增强树脂,如果停机时间超过30分钟,应将料管清洗干净.,对于含PC的树脂,不要将料管温度降至160degC以下,Downtime:停机,模温 Mold Tempeature,Injection Molding Process,Injection Molding Process,Part Cooling and Solidification,Hot Melt,Cooled Mold,Solid Part,制件冷却和固化,热熔体,温度较低的模具,固化的制件,Mold Tempera

19、ture,模温对制件的外观很重要 模温一致对尺寸控制很重要 均匀的模温可以减少翘曲 合理的模温可以降低产品内应力 合理的模温可以改善材料流动性,Injection Molding Cooling,模温,Cooling system,Mold Cooling Series Bubbler,IN,OUT,POOR,Pin,Blade,IN,OUT,30,Cooling System,Good,Cooling System,REGRIND SUGGESTIONS Use Only Clean Non-degraded Uncontaminated Resin for Regrind Keep It As New Materi