Experiment And Numerical Simulation Research Of The Injection Molding Characteristic For Thin-Wall Plastic Parts

Nowadays, the 3C (Computer, Communication and Consumer) products, such as notebook computer and mobile telephone etc., are updated quickly and the design idea is developed forwards into being light, thin, short and small. The thin-wall design can reduce the weight and external dimension of the products, benefit integrated design and assembly, shorten production molding cycles, economize material and lower costs, etc. It has become the goal which various plastics expense profession pursue. So the thin-wall injection molding (TWIM) technology is being developed rapidly on the basis of conventional injection molding technology.This paper synthesizes the domestic and international development of TWIM technology, and considers orientation of 3C products. Experiment and numerical simulation research of the injection molding characteristic for thin-wall plastic parts are put forward. Because the research of TWIM is just at the beginning, and the theory system on it has not formed completely, moreover, it is few in domestic, this paper can reinforce domestic research in this domain, and will built the good foundation for the future research.An injection mold for simplified bottom shell of mobile phone is designed and manufactured for experiments which has 2 cavities, submarine gate and can mold plastic parts of 0.5mm wall. The molding process of plastic parts is studied using 3D numerical simulation with Moldflow software and orthogonal experiment method. The effects of process parameters (injection rate, injection pressure, melt temperature, shot size and mold temperature etc.) and its interaction on the molding characteristic of thin-wall plastic parts are discussed by single factor method and analysis of variance. The molding area which the product can be mold with ABS is drawn, it shows the molding characteristic of the product.The research results indicate that: in the process of molding thin-wall plastics parts, mold temperature is the most important process parameter, injection pressure and shot size are subordinate factors, relatively, the effects of injection rate and melt temperature are not notable. The interaction of injection rate and melt temperature is significant to the molding, relatively, the interaction of mold temperature and melt temperature is less influential and other interaction can be neglected. It really is worth mentioning that the proper shot size is the necessary condition in the molding process and injection pressure has one peak value, but toohigh value will play a block role. Then, 3D numerical simulation could be applied in analysis and mold design of thin-wall plastic parts, with high dependability.