The invention relates to a process for production of expanded pellets from a polymer melt comprising a blowing agent, said process comprising the steps of:
a) pressing the polymer melt comprising a blowing agent through a perforated disk controlled to a temperature between 150° C. and 280° C. and into a pelletizing chamber,
b) using a cutting device to comminute the polymer melt pressed through the temperature-controlled perforated disk into individual expanding pellets,
c) discharging the pellets from the pelletizing chamber using a liquid stream,
wherein the blowing agent comprises CO2 or N2 or a combination of CO2 and N2 and the pelletizing chamber is traversed by a stream of liquid which is controlled to a temperature between 10° C. and 60° C. and the pressure of which is from 0.7 bar to 20 bar above ambient pressure, the pressure and temperature for the liquid in the pelletizing chamber and also the temperature for the perforated disk being chosen such that the pellets are expanded in the pressurized liquid by the blowing agent they contain so as to produce expanded pellets having an uninterrupted skin.
本发明涉及一种利用含有发泡剂的聚合物熔体生产膨化颗粒的工艺,所述工艺包括以下步骤:
a) 将含有发泡剂的聚合物熔体通过一个温度控制在 150 摄氏度至 280 摄氏度之间的穿孔盘,压入造粒室、
b) 使用切割装置将通过温控穿孔盘压制的聚合物熔体粉碎成单个膨胀的颗粒、
c) 使用液流将颗粒从造粒室排出、
其中发泡剂包括
CO2 或 N2 或 和 N2 的混合物,造粒室由液体流穿过,液体流的温度控制在 10°C 至 60°C 之间,压力为高于环境压力 0.7 巴至 20 巴,造粒室中液体的压力和温度以及穿孔盘的温度应选择为使颗粒在加压液体中通过所含发泡剂膨胀,从而生产出具有不间断表皮的膨胀颗粒。