| 摘要 |
In the manufacturing of substantially dry articles of an expanded thermoplastic synthetic material, during heating-up of the mould wall parts by means of steam, an air pressure which is equal to or slightly higher than the pressure of the steam used for heating-up is maintained in a mould cavity filled with preexpanded synthetic-material particles and connected via passage-openings to the steam chamber. Once the mould wall has reached the temperature of the saturated steam, the air pressure is lowered for fusing of the expanded synthetic-material particles, and the synthetic-material particles are heated to the temperature necessary for fusing or sintering by the steam flowing in. An apparatus (10) suitable for carrying out the method is to have at least one connecting line (30) which leads from the mould cavity (17) to the outside of the foaming device and is provided with a connected valve-controlled operating line (37), in order in this way to introduce compressed air for building up the counterpressure in the mould cavity and for sucking out steam. At least one of these operating lines can accommodate the means (31) for filling the mould. …<IMAGE>… |
