Home >> Patent Categories

Patents

Patent Search

United States Patent 5318357
Douris , ê et al. July 7, 1994

Extruder injection apparatus

Colby , Ê et al. June 7, 1994

Abstract

A screw for use in an plasticating injection apparatus includes a plurality of interrupted primary flights. An outer surface of a primary valley is formed by the primary flights and features a plurality of plateaus. The plateaus span adjacent sections of the primary flights and define shallow levels between deeper levels of the primary valleys. This depth differential contributes to a turbulent mixing action which, along with the primary and secondary valleys, contributes to improve mixing action within a metering section of the screw. The primary flights are interrupted by secondary valleys which are of opposite hand to the primary valleys.