| 摘要 |
PURPOSE:To shorten a molding cycle, and to obtain a molded piece having small specific weight distribution of a block molded piece and high quality by associating a vacuum device with a foam molding having the steps of filling preliminarily foamed particles preliminarily foamed from thermoplastic foamable resin particles in a block metal mold, thermally molding it, then cooling it, and removing it. CONSTITUTION:Metal molds 1, 2, 3, 4 are evacuated in vacuum, a plunger 31, and a hopper shutter 35 of a hopper 35 are opened, prefoamed particles (preliminarily foamed particles) are normally filled in the molding piece chambers 1 of the metal molds. Then, a heating step is divided into first stage of one direction heating, reverse heating and side heating and second stage of total surface heating, the molds are evacuated in vacuum, the heating of first stage is conducted, regulating pressure of the second stage is set higher than the set pressure of the first stage, heating it to foam mold it. After the molds 1, 2, 3, 4 are vacuum evacuated and cooled, they are once or repeatedly water cooled, drained, vacuum evacuated and cooled, and normally left to stand for, and molded pieces are removed. |
