Abstract: An underwater pelletizer cutting system allowing fine adjustments of the relative spacial relationship between an extrusion die and the blades of a cutting assembly. The cutting assembly, which may be self-aligning in nature, is borne on the end of a drive shaft driven by a motor mounted on a carriage. The carriage is moveable relative a fixed frame by a servomotor driving a ball screw. The ball screw, which preferably has zero backlash, has a shaft attached at one end to the carriage for moving the carriage. A PLC control system may be provided to accept inputs from an operator and to run a cutting program, providing appropriate signals to the servomotor to advance the cutting assembly as needed as the blades of the cutting assembly wear. The PLC system may receive signals from a measuring system adapted to measure the contact pressure between the cutting assembly and the face of the extrusion die.

Abstract: A die and a die assembly are disclosed for use in association with an underwater pelletizer. The die has unique coiled heating elements which allow for uniform heating of the extrusion orifices which pass through the die, reducing or eliminating polymer solidification within the die, thereby allowing the manufacture of uniform pellets of a specific geometry. The heating elements are contained within the die plate of the die, and in a preferred embodiment occupy annular grooves formed therein which are concentric with the extrusion orifice pattern. The die assembly includes thermally-insulating adaptors and gaskets which cover the annular grooves containing the heating elements.

Abstract: An underwater pelletizer cutting system allowing fine adjustments of the relative spacial relationship between an extrusion die and the blades of a cutting assembly. The cutting assembly, which may be self-aligning in nature, is borne on the end of a drive shaft driven by a motor mounted on a carriage. The carriage is moveable relative a fixed frame by a servomotor driving a ball screw. The ball screw, which preferably has zero backlash, has a shaft attached at one end to the carriage for moving the carriage. A PLC control system may be provided to accept inputs from an operator and to run a cutting program, providing appropriate signals to the servomotor to advance the cutting assembly as needed as the blades of the cutting assembly wear. The PLC system may receive signals from a measuring system adapted to measure the contact pressure between the cutting assembly and the face of the extrusion die.