Extruder with screw having core portion of polygonal cross-section

摘要

A screw for use in an extruder barrel for plasticizing plastic material from a solid phase to a viscous form wherein the feed screw has a cylindrical core with a helical flight extending for the full length of the screw. A selected portion or portions of the screw's core has a polygonal cross section whose apexes are parallel to the axis of rotation of such screws to thereby more precisely control the plasticizing action of the plastic material, its viscosity and temperature while providing a thoroughly mixed and homogeneous melt.