嵌入件射出成型品之品質分析

在嵌入射出製程中，嵌入件(inserts)可能是塑膠或非塑膠，為了強度的需求，常見為金屬材料與塑膠材料結合的產品，因材料特性不同而造成射出成型後易產生短射、翹曲變形、或其他的缺點。為能掌握此等問題，本論文使用Moldex3D CAE軟體進行模擬分析，並以田口方法探討嵌入件模具之橫流道、澆口設計與製程參數最佳化以得到最佳密度值。首先採用L8(27)直交表進行干擾實驗，結果顯示保壓壓力與保壓時間為重要的干擾因子；並進一步將此兩因子合併為複合干擾因子。再以L9(34)直交表進行主實驗，此時結果顯示影響成型品密度的重要因子分別為：保壓時間、保壓壓力。接著，再利用變異數分析進行S/N比與品質特性的誤差統合，在98%的信心水準之下，結果顯示影響成型品密度的重要因子與田口方法的分析結果是完全吻和的。之後更進一步利用信賴區間計算來評估因子效應的誤差，結果清楚地發現：預測值與實驗計算值在誤差範圍內，得知本實驗是足夠精確。最後，我們透過現場製程參數最佳化，得知改善製程後的拔脫扭力(pull-off torque)比原始製程有顯著提升(從7.14 N-m 增加到7.31 N-m)。

關鍵字

嵌入射出；田口方法；干擾實驗；變異數分析； S/N比；信心水準；信賴區間；拔脫扭力

並列摘要

For injection molding production, the insert molding is a common way to make multi-component product. More specific, to keep some strength, a metal insert with plastic injection is very popular in industry. However, due to the physical properties are so different between metal and plastic, it is so often to encounter many defects during the processing, such as short shot, warpage, and so on. In order to realize what happens during the insert molding, in this study we have applied Moldex3D CAE software to perform the simulation analysis. Specifically, the experimental design of Taguchi method is used to explore the runner, gate design and process parameters to obtain the optimal molding density. L8 (27) orthogonal array was used to implement the noise experiments. Results show that the packing pressure and pressure time are the most important noise factors. Furthermore, these two factors (packing pressure and packing time) are combined into a composite noise factor. In main experiment, L9 (34) orthogonal table was used for measuring the molding density. Results show that the most important factors affecting the molding density are the pressure time and packing pressure. Analysis of variance was used for pooling of errors of S/N ratio and the quality characteristics. Results show that the important factors of the molding density are entirely consistent the results by Taguchi method under a confidence level of 98%. Finally, the confidence intervals were calculated to evaluate the errors of the factors. Results also show that the predictive value and experimental one are in a very good agreement. It indicates that our studied results are accurate enough. Moreover, through the real experimental testing from factory, the pull-off torque of the product has significantly improved after the optimization of process parameters (increased from 7.14 N-m to 7.31 N-m).

並列關鍵字

insert molding ； Taguchi method ； noise experiments ； analysis of variance ； S/N ratio ； confidence level ； confidence intervals ； pull-off torque

參考文獻

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嵌入件射出成型品之品質分析

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