| 摘要 |
PROBLEM TO BE SOLVED: To melt and remove a core in a short time by fixing the core, which was made in advance from a low melting point metal, in the cavity of a mold, and molding the core and a resin integrally. SOLUTION: A mold in which a cavity is formed in the shape of a core, and the mold is combined, tin and bismuth are mixed from a gate part formed in the lower part of the mold, the alloyed low melting point metal is heated, melted, and packed in the cavity, and a hollow core 4 is obtained. The core 4 is set in the mold in which the cavity in the shape of a hollow resin molding and a core support part is formed, injection is done with the use of a nylon resin. A molding in which the low melting point metal core 4 and a hollow resin molding 8 are integrated is immersed in heated ethylene glycol 9, the ethylene glycol is made to penetrate into the core 4 to melt it away. |
