Polymer Systems Inc. (Booth N6340) has introduced at NPE its EGP extrusion gear pumps aimed at challenging materials such as foam, vinyl and highly filled resins.
The foam gear pumps feature seals that eliminate leakage through an extended-length, special thread pitch and progressive cooling of the melt. The nongalling sealing material allows good heat dissipation compared to pumps with seals made from carbon and stainless steel. The design prevents leakage of blowing agents, including inert gases.
EGP pumps for vinyl and other thermally sensitive polymers address residence time and distribution. This series uses a fully jacketed housing for temperature control and elimination of hot spots. Noncorrosive metals and polished flow passages reduce residence time, material degradation and polymer hang-up. Adjustable bleed ports allow porting of the material used to lubricate the bearings to the pump exterior.
The Hickory, N.C., firm also debuted two hydraulic screen changers to its HSC line.