PRODUCTION OF SPHERICAL THERMOPLASTIC RESIN PARTICLE

摘要

PURPOSE:To efficiently produce fine spherical particles having a uniform particle shape and a high sphericity in a process for extruding and pelletizing a thermoplastic resin by adopting the hot cut method and specifying the molten resin temp. and resin extrusion rate. CONSTITUTION:A thermoplastic resin is extruded through a die 4 under such conditions that the molten resin temp. at the outlet of a die 4 installed at the front end of an extruder 1 is kept at a temp. 50-120 deg.C higher than the pour point of the resin; and the resin extrusion rate per hole of a nozzle 8 per blade of a cutter 5 is kept in a range of 0.3-3kg/hr. Just after extruded, the resin extrudate is cut in air by a blade of the cutter 5 rotating on the surface of the die 4, and the resulting pellets are cooled (coolant inlet 6; resin and coolant outlet 7) to produce spherical particles.