Patent ID: 6164810
Filing Date: 2000-12-26
Classification: B29C

Abstract:
A rotary screw extruder for extruding resin material and for removing volatiles therefrom comprising:a barrel having a generally cylindrical chamber with a feed opening through said barrel into said generally cylindrical chamber;a screw rotatably residing in said generally cylindrical chamber, said screw including a drive end, a feed section, a melting section and a pumping section, said feed section residing between said drive end and said melting section, said melting section residing between said feed section and said pumping section, said screw having at least one gas vent hole in said melt section positioned from about 0 to about 2 screw diameters from said feed section, said melting section including a pumping flight and a barrier flight, said barrier flight intersecting said pumping flight, said barrier flight having a radial height which is greater than a radial height of said pumping flight, said at least one gas vent hole residing between said pumping flight and said barrier flight; andan axial bore into said screw for venting gases from said barrel through said gas vent hole and into said axial bore.