PROCEDURE FOR THE MANUFACTURE OF A FOAM GRANULATE AND FOAM GRANULATE OBTAINED BY THIS PROCEDURE.

摘要

A process for producing a foam granulate is described, in which a thermoplastic synthetic material is placed in an extruder, the synthetic material is cast, a pressurized expanding agent is fed by one or more injection nozzles, the molten material enriched with the Expander medium is foamed, while exiting through a perforated plate disposed at the extruder outlet, and is granulated by a cutting device arranged behind the perforated plate. A device for implementing the procedure and foam granulation is also described. The invention is characterized in that the molten material is cooled in a controlled manner while leaving the perforated plate and exiting directly into a circulating cooling medium, because the temperature of the molten material and the temperature and the pressure of the cooling medium are regulated by such that, once the molten material leaves the perforated plate, the surface of the molten material is directly hardened into a closed film with a uniform surface having a thickness ranging from 10 to 500 µm, preferably 20 at 200 µm, once the molten material is foamed and a granulate with a rounded surface and with a density of 10 to 600 gr / l is formed. Thus, a hemispherical granulate with a uniform surface is obtained.