Apparatus for removing volatiles from plastic materials delivered to an extrusion or injection molding machine

An apparatus for removing moisture and other volatiles from a particulate plastic material which is plasticized in a plastics injection molding or extrusion-type machine having a plastics material inlet, a heated barrel and screw, comprising:

• (1) guide means extending upwardly from said material inlet for guiding and feeding the particulate plastics material downwardly into said material inlet and along said heated barrel, said guide means having apertures in the sidewalls thereof and heating means for heating air passing therethrough;
• (2) perforated conduit means disposed substantially axially in said guide means;
• (3) suction means for applying a suction to said perforated conduit means such that a flow of air is heated by said heating means, drawn through said apertures in said guide means, through the downwardly flowing particulate plastics material, through said perforated conduit means and upwardly out of said perforated conduit and out of said guide means;
• (4) means for heating and working the particulate plastics materials passing along said heated barrel and screw wherein contact with the heated barrel and screw releases volatiles from the plastics material, and whereby said released volatiles are withdrawn from said barrel by action of said suction means through said material inlet and said perforated conduit and passed out of said perforated conduit and said guide means in the said flow of heated air;
• whereby, a flow of said plastics material which is substantially free of moisture and other volatiles is provided to said plastics molding machine for plasticization.