Process Optimization For Injection-compression Molding Based On Cae

Injection-compression molding(ICM),which can solve internal stress problems effectively, was widely used in optical lens and compact disc andμclass of accuracy standard product in manufacture area. The processing parameters directly affect the flow status of the melt and quality of final products during the molding process, it is a prerequisite for forming high-quality products to obtain and maintain the optimal process parameters. This article described the mechanism of injection compression molding and the influence of processing parameters on the two quality indexes including warpage and shrinkage. Simulation experiments and optimization of process parameters were conducted for two typical products of ICM using the Taguchi DOE and the numerical simulation method. The main work is focused on such aspects as follows:1) Based on the compressible flow of viscous fluid under non-isothermal conditions, a unified theoretical model of filling/post-filling stage of ICM for 3D thin parts is developed based on some assumes and simplifications. The flow state,the mechanism and characteristics of heat transfer were considered.2) In accordance with the special characteristics of ICM, two kinds of optical plastic products were chosed as typical cases for analysis, which were compact disc with even thickness and lightguide with uneven thickness. Analysis of the characteristics of the products, conditions of moulding, raw materials, factors to consider and considerations of mold design.3) Taguchi DOE experiment was conducted based on simulation results of ICM, important factors and levels impacted on product qualities were selected, simulation experiments of the compact disc and lightguide were conducted separately, and the results were dealed; the optimal factor level combinations were abtained, the significance of processing parameters are determined. The conclusion was as follows: As to the compact disc, fill time and compression rate were the main parameters of the shrinkage, switch time and fill time were the main parameters of the warpage. As to the lightguide. mold temperature,melt temperature and injection speed were the main parameters of the shrinkage; compress force was the most important parameter of the warpage.