Research on effects of injection process parameters on the molding process for ultra-thin wall plastic parts

Thin-wall injection molding has a lot of obvious 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 ultra-thin wall plastic parts have great application potentialities on MEMS. However, the injection molding process becomes more difficult and complicated with the reducing of the part thickness, systematic investigation is lacking in molding characteristics for ultra-thin wall plastic parts. An injection mold in which ultra-thin wall plastic parts can be molded is designed and manufactured. 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 part thickness) on the molding process for ultra-thin wall plastic parts is discussed. The results show that part thickness is the decisive parameter to the molding, metering size and injection rate are the principal factors in molding process, accelerating injection rate can bring a great 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.