The programmed control of injection speed is to divide the injection stroke of screw into 3~4 stages, and the appropriate injection speed is used in each stage respectively. For example: at the beginning of the molten plastic through the gate to slow down the injection rate, in the mold filling process using high-speed injection, at the end of the mold to slow down the speed. This method can prevent the overflow, eliminate the flow mark and reduce the residual stress of products.
