| 摘要 |
PURPOSE:To shorten the total molding cycle and obtain a foam molded item having favorable external appearance by a method wherein the exhaust of gas, which is present in gaps among foaming particles, by steam can be performed with the foaming particles kept compressed. CONSTITUTION:Pressurized gas with a pressure P1 is forced in steam chambers 16 and 16'. Foaming particles in a hopper 1 is charged into a cavity 21. The compressibility of the foaming particle by the pressurized gas depends on the kind of resin and sets to be 40-70%. Steam, the pressure of which is higher than the pressure P1 by 0.2kg/cm<2> or more, is fed from a steam pipe 17' through the steam hole 20' of a movable mold 12 in a cavity 21 and, after that, discharged through the steam holes 20 of a fixed mold 11 from a degassing pipe 18. Thus, the gas, which is present in gaps among the foaming particles, is exhausted by being accompanied with the steam. After the degassing treatment, pipes 19 and 19' are opened so as to bring back the pressure in the cavity 12 to the atmospheric pressure and to restore the foaming particles. After that, the chambers 16 and 16' are heated so as to fuse the foaming particles one another. Thus, a molded item, which is excellent in fusibility and external appearance and has few void is obtained. |
