METALLIC MOLD HAVING EXTENDED HEATING SURFACE

摘要

PURPOSE: To provide a metal mold shell body assembly having an inside surface heating the outside surface exposed to a heat source and a cast gelable thermoplastic material to the melting temp. of the thermoplastic material to mold a thin-walled solid plastic shell. CONSTITUTION: Respective heat transfer pins 30 have the outer surfaces exposed to a heat source for heating a mold shell body and large diameter head parts 30a and the large diameter head parts are arranged so as to form parallelly arranged relation with respect to the outside surface of the mold shell body. The respective heat transfer pins are connected to the mold shell body by the capacitive welding nuggets formed only between the large diameter head parts and the mold shell body and the large diameter head parts of the heat transfer pins of the outside surface of the mold shell body and the clean surface parts free from welded parts between the large diameter head parts are combined with the expanded surfaces of the heat transfer pins to demarcate the total heat transfer surface larger than the whole of the outside surface of the mold shell body and, by this heat transfer surface, the heat flow to the thermoplastic material cast on the inside surface of the mold shell body from the heat source is increased.