| 摘要 |
PURPOSE:To stabilize heat shrinkage of an unformed part of a sheet, by cooling the sheet from both sides by clamping it between a cooling plate and a cooling member immediately before or after mold closing, in multi-cavity molding of a deep-drawn plastic container by a sheet melting forming method. CONSTITUTION:Immediately before or after completion of drawing of a sheet by a plug, a cooling plate 32 is driven by an air cylinder 20 to move downward, whereby the sheet is cooled by clamping it between a highly heat-conductive cooling member 16 on the outside of an annular body and the cooling plate 32. The cooling plate 32 is suitably controlled as to the timing for clamping, under the driving of the air cylinder 30. Concurrently, pressurized air is sucked in through an annular gap 29 between an upper mold 24 and the plug 20 onto the drawn molten plastic sheet 1, and a mold cavity 11 is evacuated through vent holes 19. The drawn molten plastic sheet 1 is thereby expanded, and is cooled by making contact with the mold surface, thereby being formed to be a deep-drawn container 33. The timing for clamping between the cooling member 16 and the cooling plate 15 is simultaneous with or immediately after mold closing, which is carried out simultaneously with completion of drawing of the sheet by the plug. |
