| 摘要 |
PURPOSE:To obtain a molded container having the highest strength within the limit height heaped by the given base material by taking the limited free blowing structure accomplished by keeping the space between molds in a vacuum atmosphere. CONSTITUTION:Plasticized, softened, expanded and heated sheet is guided to a forming station, and stretched by the molds 2, 3. When air tightness is made by mold clamping between the circumference of the mold and an expansible sheet, vacuum pressure is applied by a vacuum pump to the expansible sheet through the piping 5 and the fine pores 4 perforating both surfaces of each mold. Therefore, the stretched sheet which is kept still in a plasticized state is expanded between the molds under balanced tension caused by the gas pressure in independent foams and the viscoelastic force of thermoplastic resin forming foams and the viscoelastic force of thermoplastic resin forming foams and finally the resin heat is taken from the mold surfaces 2, 3 and the resin is cooled and hardened to obtain a molded body. |
