模具旋轉機構對於塑膠射出成型之結合線消除的效果

Abstract

本研究設計一裝置於模具內部之旋轉機構，於射出成型製程充填階段，藉由旋轉體表面形狀擾動塑膠高分子流體，來影響結合線的結構形成，進而對結合線外形造成改變。利用改變旋轉體速度、外形及實驗材料製作不同實驗參數的試片，並進行結合線外觀觀察比較。本研究利用3D TIMON以及FLOW-3D兩套數值模擬軟體，對於實驗材料進行充填模式以及旋轉機構對於高分子流體的影響進行模擬分析。

實驗結果顯示，旋轉機構對於射出成型製程中所造成的結合線，確實可以達到破壞以及扭轉的效果，並可用肉眼觀察出差異性。在ABS及ASA材料上，擾動效果較為明顯，效果也較佳，但在PMMA及PC上則因其材料特性而產生頂出破壞以及流紋線生成等問題。使用3D TIMON以及FLOW-3D的數值模擬結果與實驗結論比較也得到近似的結果。

A built-in rotor inside the mold was designed. The rotor’s surface was constructed with the purpose of disturbing the skin layer and core layer of the molten material and hopefully destroy the fountain flow structure of plastic flow. Several specimens were made by changing the rotor’s surface profiles. Angular velocity, four polymers were chosen as the parameters. 3D TIMON and FLOW-3D were the software used to simulation the filling process. Experimental results showed that the rotor in the mold did twist the welding line and in some cases even made the welding line disappear. The effects were more apparent in ABS and ASA. While on PC and PMMA specimens’ surfaces were found showing surface vein near the rotor. PMMA is easily occur fracture along the edge of rotor. Numerical analysis showed the similar results as the experiments.