| 摘要 |
1489462 Moulding thin-walled articles R P DUCRUEZ 16 Jan 1975 [18 Jan 1974] 1955/75 Heading B5A In a process for forming thin-walled products, e.g. beakers and egg containers, in a mould cavity 6 which communicates with an annular passage 24 situated where the mould parts 13, 14 meet, a vacuum is applied to the mould cavity so as to draw granules of a thermoplastic resin from a hopper 1 through the passage 24 and into the mould cavity which is then sealed off and the mould is first heated and then cooled. After filling the cavity the mould parts may be pressed together to compress the moulding material. Excess granules remaining in the passage 24 may be returned to the hopper 1 through a duct 9 by means of an air nozzle 11. Vacuum is applied through perforated plugs 22, 22a which can also be used to supply compressed air to eject the moulded articles. Alternatively ejection may be effected by movement of the plugs 22, 22a to the right. A valve structure 20 is provided for sealing off the mould cavity 6. An agitator 3 may be connected to the hopper 1. |
