Abstract: The analysis of warpage occurring in the injection molding process for a multi-pin plug insulator was performed by using a Moldflow software to determine maximum number and location of mold gate. On the basis of the characteristics of multi-hole structure, small hole size and high precision of hole position in plastic insulator parts, the injection mold was designed by adopting a series of new techniques including a twice fixing core for mold, a combination process for core-retainer plate and precise positioning for the fixed and movable mold cores to ensure a position accuracy for the holes. The results indicated that the total shrinkage deformation and shrinkage from each direction were optimized when using a side and sub gate with a short edge. It was confirmed by practical production that the designed mould had a reasonable structure and could be used to produce plastic parts with a high quality.

Key words: plug insulator, multi-hole structure, position precision, Moldflow software, injection mold