Home >> Patent Categories

Patents

Patent Search

United States Patent 5599098
Douris , ê et al.

Extruder screw with multiple flighting

Christie February 4, 1997

Abstract

A plastic materials screw has a metering section defined by a series of axially extending discontinuous and partially overlapping flightings. The flightings overlap each other by about a half to one turn to define overlapping portions whereby the flow in the primary channel is divided into a pair of secondary flow channels which have velocity profiles normal to the channel root greater than that in the primary channel. At the end of the overlapped portion, the first flighting is discontinued and the second flighting continues with a result that the flows are recombined in a distributive manner to provide improved mixing with a minimum of additional shear stress.