《塑胶设计原理讲解材料》由会员分享，可在线阅读，更多相关《塑胶设计原理讲解材料（154页珍藏版）》请在金锄头文库上搜索。
1、射出成型塑膠產品與模具設計 Injection Molding Plastic Part showing a dramatic cooling time reduction of 94% (15/16) .,平板和肋板的比較Comparison between Plain filling pattern, weld lines and air traps are changed.,多澆口設計 Multi-Gate Design,閥式澆口 Valve Gate,矩形邊緣澆口設計 Rectangular Edge Gate Design,扇形澆口設計 Fan Gate Design,重疊式澆口設計
2、 Overlap Gate Design,凸耳澆口設計 Tab Gate Design,L = 0.5 0.75 mm d = 澆口直徑( mm ) gate diameter in mm t = 零件壁厚( mm ) wall thick. in mm A = 型腔表面積 ( mm ) surface area of cavity in mm n= 材料常數 material constant 0.6 for PE, PS 0.7 for POM, PC, PP 0.8 for CA, PMMA, PA 0.9 for PVC,針點澆口設計 Pin Gate Design,d,L,t,潛伏式
3、澆口設計 Subgate Design,W= w= 澆口寬度 mm gate width in mm A= 型腔表面積 mm2 surface area of cavity in mm2 n= 材料常數 material constant 0.6 for PE, PS 0.7 for POM, PC, PP 0.8 for CA, PMMA, PA 0.9 for PVC 澆口厚度 gate thick. in mm = nt t= 零件壁厚 wall thick. in mm ,水力直徑 Hydraulic Diameter,Where is the hydraulic diameter 水
4、力直徑 A is the cross-sectional area of the flow 流路斷面積 P is the wetted perimeter 濕周長,水力直徑 Hydraulic Diameter,在不同剖面形狀，相同斷面積下之變化 Various runner profiles, based on the same cross-sectional area,流道尺寸設計 (1) Runner Sizing (1),D: 流道直徑 ( mm ) runner diameter in mm W: 下游塑膠重量 ( g ) downstream plastic weight L: 流
5、道長度 ( mm ) runner length in mm,流道尺寸設計(2) Runner Sizing (2),流道尺寸設計(3) Runner Sizing (3),流道尺寸設計(4) Runner Sizing (4),流道尺寸設計(A1) Runner Sizing (A1),G : 重量 weight S : 零件厚度 thickness D : 參考直徑 reference diameter,流道尺寸設計(A2) Runner Sizing (A2),G : 重量 weight S : 零件厚度 thickness D : 參考直徑 reference diameter,流道尺
6、寸設計(B) Runner Sizing (B),D : 參考直徑 reference diameter L : 長度 length fL :長度係數 Length coefficient D : 流道直徑 runner diameter,冷料井設計 Cold Slug Well Design,冷料井設計 Cold Slug Well Design,澆道襯套尺寸 Sprue Bushing Sizing,熱澆道設計 Hot Runner Design,熱澆道的問題似乎發生在三處: 1. 澆口直徑 2. 澆口長度 3. 噴嘴孔徑 Problems with hot runner seems to
7、 be in three places: 1. Gate diameter 2. Gate land 3. Nozzle orifice diameter,熱澆道的問題所在 Where Causes Problems with of Runner,任何發生在澆口處的發赤或噴流，表示澆口太小。 變褐則表示材料過熱而劣解。,Any blush or jetting at the gate means the gate is too small, and brown discolorations mean the material is being degraded by too much heat
8、.,受限的塑流通道 Restricted Flow Path,BROWN STREAK WITH FLOW LINES A brown streak on the part molded from easy- flow polycarbonate with the flow lines.,為了保持澆口暢通而格外加熱塑料，加上塑料在射出時通過長澆口時承受的剪切力，有可能造成褐線。,It was probably a combination of shear through the long land of the gate during injection and the extra heat
9、needed to keep the gates open that are causing the brown streak.,褐線 Brown Streak,只以噴嘴口徑去配合熱澆道口徑是不對的。 首先要將澆道口徑加大，以配合下游塑流通道口徑，然後再加大噴嘴口徑以配合澆道口徑。,It isnt just sizing the nozzle orifice to match the hole in the hot sprue bushing . First you might have to increase the hole size of the sprue bushing to mat
10、ch the flow channel diameter, then drill the nozzle out to match the sprue diameter.,受限的塑流通道 Restricted Flow Path,理想的澆道襯套設計 Optimized Sprue Bushing Design,當塑流通道受限於小或長的澆口，成型技術員常將設定溫度調高，以確保型腔充填、保壓無虞。,When the flow path is restricted by a small gate diameter or a long land length, you will usually see
11、higher heat settings being used by the molding technicians to get the parts to fill and pack out. 這樣的作法產生的問題有製品的翹曲，澆口的外觀缺陷和長的成型時間。 The problem with this approach is that it usually causes warpage of the parts, cosmetic defects around the gate area, and long molding cycles.,受限的塑流通道 Restricted Flow Pa
12、th,如果歧管溫度設定得比料管前區為高，澆口尺寸或許有問題。 如果必須將噴嘴溫度設定得特別高，噴嘴口徑或許沒配合上熱澆道口徑。,If you find you have to run the manifold heats higher than the front zone of the barrel, you probably have gate sizing problems. If you have to run the heats up on the nozzle, the nozzle orifice probably hasnt been drilled out to match
13、the hot sprue bushing diameter.,受限的塑流通道 Restricted Flow Path,如果塑流通道的尺寸正確，料管的前區、噴嘴和加熱歧管的溫度可以設定得一樣； ABS：232 C、易流PC：274 C。,If the flow path is sized correctly, you will be able to set the heat settings on the front zone of the barrel, the nozzle, and the heated manifold, such as 232C across the board f
14、or ABS or 274C for easy-flow PC.,受限的塑流通道 Restricted Flow Path,易流的PE和PP : 壁厚的50% 50% of wall thickness for easy-flow PE and PP ABS, SAN和壓克力: 壁厚的75% 75% of wall thickness for ABS, SAN, and acrylics PC/acetal/PVC/加玻纖材料和PPO : 壁厚的90% 90% of wall thickness for PC/acetal/PVC/glass-filled materials and PPOs
15、,熱澆道模具的澆口直徑 Gate Diameter for Hot Runner Molds,澆口長度應小於0.125mm。 Land should be no longer than 0.125mm. 諮詢熱澆道製造廠，以獲得正確的澆口長度。 Consult with your hot runner manufacturer for correct land length.,熱澆道模具的澆口長度 Gate Land Length for Hot Runner Molds,排氣系統設計 Venting System Design,徐鑫 XUXIN,為何排氣仍然還是一個問題？ Why venti
16、ng is still a problem ? 因為降低射速，讓積風有較多的時間逃氣，是一件太容易的事。但是 Because it is too easy to slow down the injection speed and give the trapped air more time to escape. But .,排氣 Vent,射速一降，熔膠溫度很快降低，射壓必須提高，殘餘應力隨之提高，翹曲的可能性增加。 如果想藉提高料溫，以降低射壓，料溫必須升得很高，這樣又會引起塑料裂解。 When injection speed is lower, melt temperature goes down very fast, injection pressure has to be increased, residual stress is increased and the possibility getting warppage becomes higher
