熱流板中熱管對溫度均勻化之研究

Study on the Homogeneity of Temperature Distribution Using Heat Pipe Design in Hot Runner Manifold

魏納斯(Ratno—Dini Pitoyo)

指導教授 ： 陳夏宗

中原大學/工學院/機械工程研究所/碩士(2010年)

https://doi.org/10.6840/CYCU.2010.00621

摘要

中文摘要
熱澆道系統因具有可準確調整製程溫度、均勻分配熔膠進入多模穴、較佳的熔膠溫度均勻度、可改善產品機械性質、降低成型壓力、降低成型週期與減少材料浪費等多項優點而愈來愈受市場歡迎。
但如何控制溫度均勻度仍然是熱澆道系統的一大挑戰，因此本論文即致力於研究如何利用熱管來改善熱澆道系統中熱流板的溫度均勻性。首先，將加熱棒加熱並量測加熱棒上的溫度分布，再將此溫度分布輸入Ansys做為加熱棒的模擬條件，再進行熱管對於熱流板溫度均勻度的改善實驗與模擬分析，實驗中使用兩支加熱棒來加熱熱流板模塊，並設計有無熱管、搭配2支熱管、搭配4支熱管與搭配6支熱管共11組實驗，以進行詳細的溫度均勻性分析比較。
實驗結果顯示搭配愈多的熱管可達到最好的溫度均勻度，而模擬結果也顯示同樣的結論。在模擬結果方面，無熱管、搭配2支熱管、搭配4支熱管與搭配6支熱管的最小溫差分別是6.958°C、6.651°C、3.535°C與 2.234°C，而實驗結果是24°C、19°C、16°C 與15°C。另一方面，模擬與實驗結果也都顯示愈多的熱管將使熱流板的加熱速度愈快到達250℃的目標溫度，也因此可以更節省能源的使用；在無熱管、搭配2支熱管、搭配4支熱管與搭配6支熱管的最短加熱時間，模擬結果方面分別是435秒、426秒、414秒與400秒，而實驗結果分別是445秒、435秒、420秒與410秒。因此，6支熱管設計的熱流板可具有最佳溫度均勻度與最快的加熱速度，但如果考慮熱管成本，4支熱管的設計可兼顧成本與效益。

關鍵字

ANSYS ； 熱管 ； 溫度分布 ； 熱流道

並列摘要

Abstract

The hot runners injection mold system becomes more popular thanks to its advantages over the conventional injection mold system. These advantages include providing precisely adjustable process temperature, uniform filling in multi cavity moulds, better heat distribution within the mould, improvement on mechanical properties of injected product, reduction in injection pressure, shorter cycle time, and less production cost.
One of the main challenges remaining is how to provide uniform temperature distribution during the heating process. This study offers an improved method on temperature distribution on the hot runner manifold by investigating the effect of heat pipes fitting inside the manifold.
This study begins with an experiment on the tube heated by heat pipes. Using its temperature distribution result, the heat flux distribution is then investigated using Ansys as CAE tool. This heat flux will then be applied to future 3d manifold designs. There are 12 designs modeled with 4 cases. These cases are: manifold without heat pipes, manifold with 2 heat pipes, manifold with 4 heat pipes, and manifold with 6 heat pipes. Each case will have one design to be manufactured so the results can be compared.
The simulation and experiment results showed that better temperature distribution can be achieved by fitting more heat pipes in the manifold. The simulation results showed that the minimum temperature differences in each case were 16.958°C, 6.651°C, 3.535°C, and 2.234°C (manifold without heat pipe, with 2 heat pipes, with 4 heat pipes, and with 6 heat pipes respectively), while experiment results gave 24°C, 19°C, 16°C, and 15°C.
More heat pipes also gave faster heating up which means less energy consumption. Simulation results showed that to reach 250°C the time required was 435 s, 426 s, 414s, and 400s (manifold without heat pipe, with 2 heat pipes, with 4 heat pipes, and with 6 heat pipes respectively). The experiment showed it needed 445s, 435s, 420s, 410 for manifolds without heat pipes, 2 heat pipes, 4 heat pipes, and 6 heat pipes respectively. Considering cost, the optimum number of heat pipes fitted was four. The improvement given by using six heat pipes was not cost effective, hence four heat pipes are optimum.

並列關鍵字

Ansys ； heat pipes ； temperature distribution ； hot runner

參考文獻

2. D. Frenkler and H. Zawistowski, Hot Runners in Injection Moulds, Rapra Technology Limited, Shawbury, 2001, p3.

3. P. Unger, Hot Runner Technology, Hanser, Munich, 2006, p9.

4. D. Frenkler and H. Zawistowski, Hot Runners in Injection Moulds, Rapra Technology Limited, Shawbury, 2001, p73.

5. P. Unger, Hot Runner Technology, Hanser, Munich, 2006, p38.

7. A. Demirer, Y. S0ydan, and A.O. Kapti, An Experimental Investigation of the Effects of Hot Runner System on Injection Moulding Process in Comparison with Conventional Runner System, Materials and Design, 2007, 28, 1467-1476.