| abstract |
production of expanded pellets the invention relates to a process for producing expanded pellets from a thermoplastic elastomer having an elongation at break greater than 100% measured according to din en 150 527-2, said process comprising the steps of : (a) pressing a molten polymer comprising a blowing agent through a perforated disc (18) controlled at a temperature between 150 ° C and 280 ° C in a pelletizing chamber (26), (b) using a cut (20) to fragment the melted polymer pressed through the perforated disc (18) into individual expanding pellets, (c) discharge the pellets from the pelletizing chamber (26) using a liquid stream (36), in which the The expansion comprises co2 or n2 or a combination of co2 and n2 and the amount of blowing agent in the melted polymer comprising a blowing agent is in the range of 0.5% to 2.5% by weight and in which the mixing chamber pelletizing (26) is crossed by a liquid stream that is controlled at a temperature between 5 ° c and 90 ° c whose pressure is from 0.1 bar to 20 bar above ambient pressure, the pressure and temperature for the liquid in the pelletizing chamber (26) and also the temperature for the perforated disc (18) being chosen in such a way that the pellets are expanded in the liquid pressurized by the blowing agent they contain, in order to produce expanded pellets having an uninterrupted film. |