Underwater pelletizer die system for forming multisize thermoplastic pellets

摘要

An underwater thermoplastic pelletizer has an extruding die, and a cutter for cutting a thermoplastic polymer extruded from the die into pellets as the molten polymer is solidified under water that is circulated to cool the extruded polymer and convey the pellets away for collection. The extruding die includes a die plate that is mounted in the face of the die concentric with and opposite the cutter and has a plurality of groups of extruding die holes that are connected in the die to a central main feed passage by separate radially extending distribution feed passages. The die holes in the groups are arranged in circular patterns of uniform radius about a center line intersecting with a circle concentric with the cutter path and the groups are equally angularly spaced about the cutter center line. The die holes in each group may have a uniform size different from that in one or more of the other groups or the die holes in each group may be different in size wherein the groups of holes are all alike with multisize holes.