Optimization of wedge-shaped parts for injection molding and injection compression molding

The light guide is one of important components in the backlight system,of the LCD module. In this study, both injection molding(IM) and injection compression molding(ICM) were applied in the manufacturing of a wedge-shaped light guide. The relationship between the process parameters and the product shrinkage was investigated. The process parameters including injection velocity, melt and mold temperatures, the packing pressure, the packing period and the cooling time on quality of IM and. ICM parts were studied. For ICM process, the mold-open distance was also included in the analysis. Both the numerical simulations and experiments were conducted to study the effects of the process conditions on the shrinkage of alight guide. It was found that the optimum sets of corresponding processing parameters were the same for both IM and ICM processes.. The results also showed that ICM brought larger shrinkage for a wedge-shaped part. (C) 2003 Elsevier Science Ltd.