電子與資訊等產品之發展趨勢，已完全走向「輕、薄、短、小」的設計理念，產品的設計，強調產品的可攜性與輕便性，使得預防成品翹曲變形益顯重要，殘留應力為其主要成因。本研究針對薄殼射出件，分成兩大部份：(一)在不同的熔膠溫度、模具溫度、保壓壓力和射出速率的製程參數下，對翹曲變形的影響做一研究與討論。研究中分別使用了以C-MOLD做模擬和實際射出成品。使用田口實驗設計方法，有系統的減少了實驗的次數來進行製程參數的研究。實驗結果顯示，升高熔膠溫度及保壓壓力有助減少翹曲變形。模具溫度和射出速率則無一定模式，這與塑料的性質有關，模擬與實驗的趨勢大致相同，並找到了最小翹曲變形的製程組合，其中，保壓壓力為最具影響力的因子。(二)在不同熔膠溫度、保壓壓力和模具溫度的製程參數下，對殘留應力做一研究與討論。研究中也分別使用了C-mold與熱黏彈做模擬，和實際射出成品以剝層法量測殘留應力。實驗結果顯示，減少保壓壓力、升高模具溫度與熔膠溫度，皆可減少殘留應力，其中溫度的變動為對殘留應力最具影響。

The development of electronic and communication products are in a revolution toward light, thin, short and small. The improvement of the manufacturing technique for plastics is becoming important. Warpage induced by residual stresses is the common defect of an injection molded products, especially for thin-walled part. In order to investigate the warpage and residual stresses in thin-walled injection, this research is separate into two parts: (1) Study on warpage resulted by different melt temperature, mold temperature, packing pressure and injection rate. Both simulations using commercial package C-mold and experiments were performed. Taguchi method was used to minimize the number of simulations and experiments in study the effect of the processing parameters. It was shown that higher melt temperature, packing pressure and injection rate could minimize the warpage. Among those, packing pressure was the most effective process condition that affects warpage. (2) Study on residual stress with different melt temperature, mold temperature, packing pressure and injection rate. Simulations using C-MOLD and thermo-viscoelastic model and experiments using layer removal method were also performed to distinct the residual stresses. It was shown that lower packing pressure, higher melt temperature and mold temperature could minimize the residual stresses.

參考文獻
[1] F. Boitout, J.F. Agassant and M. Vincent, “Elastic Calculation of Residual Stresses in Injection Molding”, Intern. Polymer Processing X, Vol. 3,p.237-242, 1995.
[2] K. M. B. Jansen, D. J. Van Dijk, and M. H. Husselman, “Effect of Processing Conditions on Shrinkage in Injection Molding”, Polymer Engineering and Science, Vol.38, No. 5,p.838-846, 1998.
[3] Takaaki Matsuoka, Jun-Ichi Takabatake, Akihiko Koiwai, Yoshinori Inoue, Satoru Yamamoto, and Hideroh Takahashi, “Integrated Simulation to Predict Warpage of Injection Molded Parts”, Polymer Engineering and Science, Vol.31, No. 14,p.1043-1050, 1991.
[4] K. M. B. Jansen, R. Pantani, and G. Titomanlio, “As-Molded Shrinkage Measurements on Polystyrene Injection Molded Products”, Polymer Engineering and Science, Vol.38, No. 2, p.254-264, 1998.
[5] K. K. Kabanemi, H. Vaillancourt, H. Wang and G. Salloum, “Residual Stresses, Shrinkage, and Warpage of Complex Injection Molded Products: Numerical Simulation and Experimental Validation”, Polymer Engineering and Science, Vol.38, No. 1, p.21-37, 1998.
[6] W. F. Zoetelief, L. F. A. Douven, and J. Ingen Housz, “Residual Thermal Stresses in Injection Molded Products”, Polymer Engineering and Science, Vol.36, No. 14,p.1886-1896, 1996.
[7] N. M. Neves and A. S. Pouzada, “The Use of Birefringence for Predicting the Stiffness of Injection Molded Polycarbonate Discs”, Polymer Engineering and Science, Vol. 38, No.10, p. 1770-1777, 1998.
[8] R. G. Treuting and W. T. Read, Jr., “A Mechanical Determination of Biaxial Residual Stress in Sheet Materials”, Journal of Applied Physics, Vol. 22, No. 2, p. 130-134, 1951.
[9] K. M. B. Jansen, J. J. W. Orij, C. Z. Meijer, and D. J. Van Dijk, “Comparison of Residual Stress Predictions and Measurement Using Excimer Laser Layer Removal”, Polymer Engineering and Science, Vol. 39, No. 10, p. 2030-2041, 1999.
[10] Keith Miller and Karthik Ramani, “Process-Induced Residual Stresses in Compression Molded UHMWPE”, Polymer Engineering and Science, Vol. 39, No. 1, p. 110-118, 1999.
[11] Mathar, J., Trans. ASME, 56, PP.249, 1934.
[12] Li, J. C. M., Canad. J. Phys., 45:493, 1967.
[13] 李輝煌，“田口方法品質設計的原理與實務”，高立圖書，2000。
[14] S. Timoshenko and S. Woninowsky-Krieger, “Theory of Plates and Shells”, McGraw-Hill Book Company, Inc., p. 81, 1959.
[15] 塑膠全球資訊網，“塑膠園地”，第十四期，2001。
[16] 塑膠全球資訊網，“塑膠園地”，第十三期，2001。
[17] C-MOLD, 2000 Advanced CAE Technology, Inc.
[18] Sam, “Polymer Property Analysis Report”, CAE-Lab NTHU, 2000.
[19] W.B. Young, “Residual Stress Induced by Solidification of Thermoviscoelastic Melts in the Postfilling Stage”, submitted to Journal of Materials Processing Technology.