薄件射出成型於充填時之二維流動模擬

Abstract

本研究以薄件射出成型中充填時的二維模擬為主，以基礎理論和數值分析法計算建構出不同幾何的流動趨勢，並利用類似的物理模型，將一般薄件充填問題視為平面的熱傳導問題，並將熔膠流動情況用熱傳導熱量流動的方式呈現，並將三維的流動情況化簡成二維的主要流動趨勢，試圖加速模擬的時間。 理論計算使用Mathematica數學軟體做運算，並和Flunet這套流體力學計算軟體所做的數值分析做比較，試圖找出最適合的二維邊界條件及參數設定。同時利用Flunet作為平面熱傳導的模擬平台，以熱量流動的方式表現出熔膠在模穴中的流動。並將設計的薄件模型(7cm×8cm)以模流軟體Moldex3D eXplorer做比較，可以得到相似的結果。

For now, the use of 3-dimentional (3D) simulation system in the analysis of model injections is time-consuming and not efficient enough for industries. As compared with 3D, 2-dimentional (2D) simulation could be much suitable for the analysis of thin models with relatively simple structure. In this study, we tried to develop a 2D simulation system for the filling of thin model injection to shorten the time needed for the analysis. This 2D simulation system is theoretically based on simplifying the geometrical characteristics of 3D structure via the setting of boundary conditions and parameters. The flow of melted plastic in the thin model injection was considered as the heat flow in the heat conduction. By converting the 3D flow condition of materials to major 2D flow tendency, the time used in simulation could be largely reduced. To optimize boundary conditions and parameters, theoretical computing was performed by the use of Mathematica software and the results were compared with the analysis obtained from Fluent. Using the Fluent software as a platform, the flow of melted plastic in the cavity was stimulated as a heat flow. The results of stimulation for a 7cm × 8cm thin model were then compared with the results collected by the use of Moldex3D eXplorer software for the same model. The results obtained from both Fluent and Moldex3D eXplorer are similar.