Importance

Loading Importance Indicators...

Abstract

A rotary extruder contains pump rings positioned at opposite ends of the rotor shaft to collect excess thermoplastic melt forced outwardly to the housing ends and to redirect this excess melt to the feed section of the extruder. Redirection of the melt is accomplished by helical grooves located on the inside surfaces of the pump rings having an axial component directed toward the center of the extruder to provide a conduit for the melt. The melt is also directed by a series of angular grooves positioned circumferentially about the rotor opposite the pump rings which rotationally and axially propel the melt as the extruder rotor rotates. The rotor shaft is supported by bearings at opposite ends of the shaft which are offset from the axial center of the bearing housing. Repositioning of the bearing housings by rotation about their axes change the axial position of the rotor relative to the inner surface of the extruder housing thereby varying the size of the feed and compression sections of the rotary extruder to accommodate different types of thermoplastic material. A feed hopper for holding thermoplastic feed has its outlet positioned above a variable speed endless belt which discharges into the inlet of a rotary extruder, the rate of delivery to the extruder being independent upon the rotational speed of the belt. A rotary gear pump is positioned between the extruder die and the extruder housing to increase the discharge pressure into the die.

Loading the Abstract Image...

First Claim