| 摘要 |
In the process, foamable plastic granules, which may already be prefoamed, are foamed in a mould (1) under the effect of steam on heated mould walls. The moulding is stabilised by cooling the mould walls and is taken out of the mould. In order to ensure uniform and complete foaming, the steam is passed through the granules. To this end the steam is allowed to flow into the mould (1) via steam inlet openings (12). Since the total cross-section of the steam outlet openings (11) is smaller than that of the steam inlet openings (12), a steam pressure builds up in the mould so that the steam is distributed over the entire mould cavity. This effect is reinforced by a buffer volume of a distribution chamber (9) and/or of a collection chamber (5). Valves (6, 10) can be provided to control the steam flow. Vacuum pumps (13) can also be connected via valves (14) to the mould cavity. <IMAGE> |
