Abstract: This paper reported a design of precision injection moulds for metal injection molds (MIM) for bases of orthodontic appliances. A mixture of stainless steel powders and ABS resin at a weight ratio of 6.5/3.5 was used as the fed material. In this mould, a push rod, a fixed distance parting mechanism with an internal and external combined structure, and a cooling water pipe with a diameter of 10 mm were adopted in the side core-pulling mechanism. The experimental results indicated that such a design provided a good solution for the problems of difficulties in feeding, demoulding and cooling during MIM process.

Key words: base of orthodontic appliance, metal injection mold, side core-pulling mechanism