Apparatus for drying polymeric material

Claim 1

In an apparatus for removing liquid from liquid-bearing polymeric material comprising an elongated shell having an upstream feed opening and a downstream discharge zone, means in a first zone within said elongated shell for working and compacting the material passed therethrough and through a second downstream zone adjacent said discharge zone to the discharge zone of said elongated shell, a restriction means positioned between said first and second zone for restricting the passage of material from said first zone to said second zone for reducing the pressure on the polymeric material passing through said restriction means, and a die having at least one orifice and being positioned downstream of said restriction means and said second zone and aT said discharge zone for reducing the pressure on the material passing through the orifice of said die, the improvement comprising: said restriction means being a valve having a valve body, an opening extending therethrough in fluid communication with the first and second zones, and a valve plug movably positioned within said valve body, said opening and said valve plug each having sidewalls and bottom walls of matable, planar configurations, said valve plug being slidably movable into and from said opening, and said valve plug having a hexagonal cross-sectional configuration with first and second opposed sidewalls of the valve plug contacting opposed side walls of said opening.