Abstract: Thin-wall injection molding has some apparent advantages such as saving materials, reducing production costs, weights and shape sizes, etc., and accelerates the rapid development of electronic productions (mobile phones, for instance). Especially the ultra-thin wall injection molding has great application potentialities on MEMS. However, due to the product thickness becomes thinner, the molding process becomes more difficult and complicated, systematic investigation is lacking in molding characteristics for ultra-thin wall plastic parts. A mold for the forming of ultra-thin wall plastic parts is designed and manufactured. By using the orthogonal experiment method (Taguchi method) and numerical simulation, the influence of different process parameters (injection rate, injection pressure, melt temperature, metering size and product thickness) on the molding process for ultra-thin wall plastic parts is discussed. The results show that product thickness is the decisive parameter to the molding, metering size and injection rate are the principal factors in molding process, higher injection rate can make a big increase in the filling ratio, melt temperature and injection pressure are the secondary factors, but higher melt temperature and injection pressure are also necessary in molding process.

Key words: Injection process parameters, Numerical simulation, Orthogonal experiment method (Taguchi method), Ultra-thin wall plastic parts