Patent ID: 6293690
Filing Date: 2001-09-25
Classification: B29C

Abstract:
A method for extruding resin material through a rotary screw extruder and for removing volatiles therefrom comprising the steps of:(a) delivering synthetic resinous material through a feed opening in a barrel, the barrel having a generally cylindrical chamber in which a screw rotatably resides;(b) rotating the screw to drive the synthetic resinous material from a feed section of the screw through a melt section of the screw to a pumping section of the screw, the melting section including a pumping flight and a barrier flight wherein the barrier flight intersects the pumping flight and the barrier flight has a radial height which is greater than a radial height of the pumping flight; and(c) venting gases from the barrel through a vent hole in the melt section, the vent hole positioned from about 0 to about 2 screw diameters from the feed section, the vent hole communication with an axial bore into the screw, gasses venting through the vent hole and the axial bore to thereby exit the barrel.