| 摘要 |
Method and device to be used in the continuous manufacture of foamed plastic in which pre-expanded granules of thermoplastic material are introduced into a channel (38) defined on at least two sides by the inside surfaces (18) of endless, perforated moving belts. Passing through a first zone (26) of the channel and in direct contact with steam injected through the belts, the granules are caused to expand further and to sinter or agglomerate to form a coherent, continuous thermoplastic strip or web (21). This is then treated by a vacuum process in a second zone (28) of the channel. In order to bring about an increase in the machine's (10) capacity for producing foamed plastic, or, alternatively, to reduce its length, the thermoplastic web (21) is cooled by a "forced cooling process" taking place in the third zone (30) of the channel in which the inner surfaces (18) of the belts are acted upon by a coolant of higher thermal capacity than air. A suitable coolant would be a liquid; a special apparatus (34, 36, 44, 46, 48, 50) is therefore provided to direct the liquid against and/or along the said surfaces (18) of the belts for at least a section (32) of the third zone (30) of the channel. |
