| 摘要 |
PURPOSE:To prevent foamed cell in a parison from being crashed, by a method wherein, after a cylindrical parison is placed in cavities made of a porous material which is connected to a vacuum suction port of a mold, a vacuum suction in the cavities is performed. CONSTITUTION:A cylindrcial parison 9, which is extruded from an extruder and in a molten condition, is clamped at both molds 11 and 11', and is placed in cavities 12 and 12'. With a vacuum pump, connected to a vacuum suction ports 21 and 21', actuated, a vacuum suction in the cavities 12 and 12' is performed through the application of a 76mm.Hg pressure difference. The surfaces of the cavities 12 and 12' is made of a porous material which is connected to the vacuum suction ports 21 and 21' through air chambers 20 and 20', respectively, whereby the parison 9 is sucked to the surfaces of the cavities 12 and 12', and is formed in the shapes of the cavities. Simultaneously, a cooling air blown in is sucked in through a suction port 31 to cool the inside of the parison 9. |
