Abstract: An injection mould for a car interior handle was designed by using an inverse blowing gas-assisted molding technology in a full injection mode. When designing the groove structure for melt overflow, cut-off valve and hot runner nozzle were introduced into the mould so as to improve the efficiency of melt overflow and also to overcome the defects appearing in the inverse blowing gas-assisted molding. With the use of a horn-shape latent gate and the reasonable setting of ejection position, the aspects without any gate and ejector marks were guaranteed for the injection-molded parts. This mould has been used for the production of parts, and the products exhibit a good appearance as well as a lightweight feature with a reduction in weight by 20 % compared with the similar products.

Key words: inverse blowing type, gas-assisted injection molding, resin-overflow groove, cut-off valve, shrinkage mark