摘要 |
<p>To provide an expansion injection molding process, which is freed from the occurrence of swirl marks on the surface of a molded article and by which foamed injection moldings having good appearance can be produced in a short molding cycle and at a low cost; and a mold for expansion injection molding. A movable mold 2 is moved toward a fixed mold 1, whereby a sealing member 6 set on at least one of a pair of facing surfaces of the mold 1 and mold 2 in the outside of a cavity is brought into contact with the other of the facing surfaces or a sealing member 6 set thereon to make the cavity 3 gas-sealed state. While keeping the gas-sealed state, the movable mold 2 is further moved toward the fixed mold 1 with the sealing member 6 compressed, whereby the volume of the cavity 3 is decreased to enhance the pressure in the cavity 3 to a level exceeding the atmospheric pressure. Then, a thermoplastic resin is injected into the cavity 3 of an enhanced pressure.</p> |