塑膠產品與模具設計.ppt

1、塑料产品和模具设计Plastic Part and Mold Design西昌裕Charles Hsu，铸造系统设计Filling System Design，西昌裕Charles Hsu，模具设计优先顺序Priorities of Mold Design，进料系统设计这些问题包括延迟现象、短射、凹面、揭发、喷雾、翘曲和较长的冷却时间。目前，可以使用CAE直接或间接预测。非统一wall thickness is the biggest trouble maker in plastic injection molding . this is especially true to thin-wal

2、l part；Including hesitation、shortshot、sinkmark、blush、jetting、war page and long cooling time etc。can be predicted By using CAE，不均壁厚非统一壁厚，壁厚设计壁厚设计，空设计(1) Coring Out Design 阀灌嘴Valve Gate矩形边灌嘴设计Rectangular Edge Gate Design，风扇灌嘴设计Fan Gate Design，L=1.3mm W=w=灌嘴宽度mm gate width in mm A=母模仁表面mm surface area

3、in mm t=零件壁厚wallthick.inmm，2，2，h1=n t，H2=wh1/L1=0.50.75，L2=h (w/2)，凸轮灌嘴设计页签设计，in mm t=零件壁厚wallthick.inmm，2，2，h1=n t，H2=0.9t L=0.5 0.75 mm d=灌嘴直径(mm) gate diameter in mm t=零件壁厚in mm a=母模仁表面积(mm) Surface area of cavity in mm n=PE的材料常数material constant 0.6、POM的PS 0.7、PC、ca的PP 0.8、PMMA、PMMAin mm，2，2 Whe

4、re is the Hydraulic Diameter液压直径a is the cross-sectional area of the flow流动闭合区域P is the wetted perimeter湿周，液压直径Hydraulic Diameter 料道大小设计(3) Runner Sizing (3)、料道大小设计(4) Runner Sizing (4)、料道大小G :重量weight S :零件厚度thickness D :参考直径reference D :参考直径reference diameter L :长度长度长度长度length fL :长度系数Length coeff

5、icient D :流道直径runner diameter，冷料井设计Cold Slug Well Design，倒推冷料井因为降低射精速度，让堆积的风有更多的时间呼吸是太容易了。但是because it is too easy to slow down the injection speed and give the trapped air more time to escape . but.排气Vent，如果发射速度下降，熔体温度会迅速降低，如果要提高材料温度，降低砂压，就要提高材料温度，这样还会发生塑料破裂。When injection speed is lower，melt tempe

6、rature goes down very fast，injection pressure has to be increased，Residual stress isboth high barrel temperature and high injection pressure are indications of flow problem in the filling system，排气Vent It is quite common that matmates最佳螺杆速度充分利用摩擦热，以使塑料流动保持最佳状态。很多充电和变形问题也很容易解决。an optimized ram speed

7、profile fully uses the friction heat to keep the best flow character istics，Which corrects many of the fill and war page propertops0.075 mm平流塑料2.0.125mm平流塑料。)3 .“深度宽度”(width) :和“流道同心宽度”(as wide as runner dia)“排气唇”(vent lip)3360 1.5mm A1“闭合”(finish)“排气通道通过大气”(vent channel to Runner) “深度”(depth):“推荐参照供应商”(refer to manufacturer s re commendation)“宽度”(width):“全圆周长”(whole perimeter)“长度”(lenge 均衡冷却(提高产品质量)even cooling(improve part quality)2。高效冷却(提高生产效率)平衡冷却设计对于控制效率工具收缩弯曲至可接受的程度至关重要。thin-wall part can not afford as much thermal induced residual stress as the conventional one