Study on Warpage & Residual Stress of Thin-walled Injection Molding

• Main Authors: Tong-Hong Wang, 黃東鴻
• Other Authors: Wen-Bin Young
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/b52m9b

碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 90 === 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.