The Processing Factors Of Microcellular Injection Molding

Microcellular injection molding is a new method for production of foam technology. Mechanical strength of products can be retained on the basis of the maximum degree of weight loss. Therefore, this technology has a wide range of applications especially in the aerospace, automotive fields. Microcellular injection molding developed early abroad. In2011, MuCell(?) from Trexel was applied in the market successfully. Microcellular injection molding is still in the numerical simulation stage in our country.In this paper, we studied the processing factors of microcellular injection molding on the bases of the two microcellular injection molding simulation and experiment platforms we established. Draw the basic law of the various process parameters on the response of the cell, weight loss, etc.The impact of injection molding process including fill percentage, melt temperature, percentage of the injected gas, injection time and the mold temperature on cell structure, maximum injection pressure, residual stress and warpage were studied. Compared those with the actual situation, analyzed the validity and limitations of this model. Compared microcellular injection molding with conventional injection molding process, analyzed the advantages of microcellular injection molding. At last, microcellular injection molding process optimized by response surface design Box-Behnken.We designed and constructed two sets gas injection system Intermittent and Limit depending on the different gas injection principle. Impact of the gas injection parameters including gas injection pressure and back pressure and injection molding process including plasticizing length, injection speed, screw speed and melt temperature on product surface quality, weight loss and cell structure were studied on the basis of Intermittent gas injection system. At the same time, we carried out a preliminary work on the Limit gas injection system; obtained the basic relationship of the gas injection quality and the weight loss on the basis of control the amount of gas injection accurately. We obtained the products with average cell diameter up to10μm based on the round thin sheet mold.