Underwater pelletizer
AssigneeSterling Extruder Corporation
InventorHoward W. Andersen
Life of this patent
Estimating the term…
Abstract
A conventional underwater plastic pelletizer of the type using a rotatable knife hub is improved by securing to the knife hub a diverter plate for confining the flow of inlet water to the region adjacent the face of the die plate. The cutting knives are mounted on the rotating hub at a rake angle with respect to the hub center and tilted at an angle with respect to the surface of the die plate so as to effectively pull a cut pellet away from an extruded plastic strand, and the die plate is heated by an organic heat exchange fluid. The result is a substantial reduction in orifices frozen off by cooled polymer.
Claims16
In an underwater plastic pelletizer of the type comprising a die plate supporting body including an inlet, an outlet and an extrusion cavity;
- a die plate on said body positioned in closing relation to said outlet defining a plurality of extrusion orifices arranged annularly thereon in communication with said cavity;
- rotatable cutting means comprising a rotating knife hub and a plurality of rotating knives mounted for rotation therewith for cutting plastic extruded from said orifices into plastic pellets;
- a water-tight housing secured to said body over said die plate having water inlet means and outlet means for permitting removal of cut plastic pellets by moving water;
- and means for heating said die plate to maintain plastic in a flowing condition as it passes through said orifices, the improvement comprising:
- (a) a diverter plate having an inlet end in communication with said water inlet means and an outlet end disposed about said knife hub, said diverter plate including a peripheral flange disposed in a plane extending parallel to and spaced uniformly from said die plate, said peripheral flange dimensioned so as to completely overlie said plurality of extrusion orifices for confining the flow of inlet water generally uniformly to the region adjacent to and across the face of the die plate and in a direction generally parallel thereto.
In an underwater plastic pelletizer of the type comprising a die plate supporting body including an inlet, an outlet and an extrusion cavity;
- a die plate on said body positioned in closing relation to said outlet defining a plurality of extrusion orifices arranged annularly thereon in communication with said cavity;
- rotatable cutting means comprising a rotating knife hub and a plurality of rotating knives mounted for rotation therewith for cutting plastic extruded from said orifices into plastic pellets;
- a water-tight housing secured to said body over said die plate having water inlet means and outlet means for permitting removal of cut plastic pellets by moving water;
- and means for heating said die plate to maintain plastic in a flowing condition as it passes through said orifices, the improvement wherein:
- (a) said means for heating said die plate comprises an organic heat exchange fluid medium.
In an underwater plastic pelletizer of the type comprising a die plate supporting body including an inlet, an outlet and an extrusion cavity;
- a generally horizontally disposed die plate on said body positioned in closing relation to said outlet defining a plurality of extrusion orifices arranged annularly thereon in communication with said cavity;
- rotatable cutting means comprising a rotating knife hub and a plurality of rotating knives mounted for rotation therewith for cutting plastic extruded from said orifices into plastic pellets;
- a water-tight housing secured to said body over said die plate having water inlet means and outlet means for permitting removal of cut plastic pellets by moving water;
- and means for heating said die plate to maintain plastic in a flowing condition as it passes through said orifices, the improvement comprising:
- (a) a generally horizontally disposed diverter plate having an inlet end sealingly in communication with said water inlet means and an outlet end disposed centrally of said diverter plate and about said knife hub, said diverter plate including a peripheral flange disposed in a plane extending parallel to and spaced uniformly from said die plate, said peripheral flange dimensioned so as to completely overlie said plurality of extrusion orifices for confining the flow of inlet water generally uniformly to the region adjacent to and across the face of the die plate and in a direction generally parallel thereto.
Dependencies are inferred from the claim text.