PURPOSE: To obtain a mold having a cavity provided with the same configuration and same size as those of a matrix by a method wherein a cavity of a synthetic rubber mold is filled with inorganic composition poured thereinto, and the composition is cured to manufacture the matrix consisting of the inorganic composition while molten alloy for die casting is cast around the matrix, and thereafter the matrix consisting of the inorganic composition is extracted and removed.
CONSTITUTION: A matrix 1, having the same configuration as a product to be molded, is manufactured from the block of ABC resin and the matrix 1 is inserted into a predetermined position in the frame body 2 for a casting mold consisting of acrylic resin or the like as a core to pour liquidous hardening silicone rubber around the core and cure it, then, obtained molded form 3 is cut into two pieces to extract and remove the core or the matrix 1. Next, plaster is poured and filled into the cavity of a silicone rubber molding mold 3, in which the cavity having the same configuration as that of the matrix is formed, to cure it and, thereafter, the plaster is calcined to form a plaster mold 4 having the same configuration as the matrix. Subsequently, the plaster mold 4 is used as a core and zinc alloy 5 for die casting, which is provided with a melting point of 380°C, is pressurized and cast around the core while the mold is cut into two pieces after cooling and the core is taken out. According to this method, the mold may be used as the mold for injection molding while combining the core with a template 6.
TANNO NORIO
MARUYAMA YOSHITOKU
