Styrefremgangsmåde i forbindelse med opskumning og sintring af plast

2.1 Foam articles are produced by allowing steam to act on the expandable polymer in a mould. In this case, the steam state is assumed to be invariable, and the steam treatment is controlled only in terms of time. If the steam state varies, the essential properties of the foam article change. With the novel process, foam articles of consistently high quality are obtained without using an excessive amount of steam. 2.2 In the case of the novel process, measuring of the flow rate (by means of a vortex-flow flowmeter), pressure and temperature of the steam is carried out. From this the amount of steam fed to the foaming apparatus at short time intervals is calculated. Subsequently, the duration of the individual phases of the steam treatment is altered - if appropriate fully automatically - in order that the foaming apparatus is fed the necessary amount of steam in each steam-treatment phase. 2.3 Production of foam articles from expandable polymers, for example from expandable polystyrene.