Underwater pelletising

摘要

In underwater pelletising of thermoplastic resin material, thermoplastic resin material is kneaded and fused in a kneading extruder, extruded from nozzles (7) of a die (2) covered with cold water, and the extruded resin material of small string shape is cut by a cutter device (5) moving along the outside surface (2a) of the die (2). When the stationary operation of the kneading extruder is interrupted in heated condition in which resin material has been supplied to the kneading extruder, the cutter device (5) is stopped, and the die (2) cools. The heating rate of the die (2) then must be increased so that the resin material in the nozzles (7) in a softened condition is turned to a fused condition, and the cutter device (5) is restarted.