An application of the design of experiment for purging of injection molding machine and hot runner mold

Abstract

This research was proposed on the experimental study on purging of an injection molding machine's barrel and hot runner mold. The Taguchi method was used to design the experiment with two level of shot size, melt temperature, injection speed, screw speed, injection pressure, back pressure and suck back position and two level of temperature at hot runner mold. Those factors were controllable factors while mixing with recycle material and moisture content of material were uncontrollable factors. The ABS resin was used to perform the experiment. It was mixed with 5% (by weight) of mica particles and acted as particle tracer and used for the first shot. Then, the barrel and hot runner mold were purged with virgin ABS. The results showed that shot size, melt temperature, screw speed and injection speed were main factors which significant for purging and the mixing recycle material effect to purging more than the moisture content in material. However the suck back position should be used during purging. The temperature of hot runner mold should be set at normal injection condition.