Apparatus for the continuous extrusion of solid articles

Claim 1

Apparatus capable of the continuous extrusion manufacture of a solid composite porous article from a substantially uniform particulate mixture of a quantity of particles of a binder material and a quantity of particles of a primary material, said primary material having a substantially higher softening temperature than a softening temperature of said binder material, which comprises: an extruder barrel housing an extrusion screw, said extruder barrel having a feed inlet and feed outlet; an elongated, smooth extrusion die attached to the feed outlet of the extruder barrel, said die defining a cavity having an inlet end, an extrusion end, and a substantially uniform cross-section, which cross-section is not substantially smaller than the cross-section of an inside diameter of the extruder barrel; means for forcibly injecting said particulate mixture into the inlet end of said die cavity; means in said die adjacent to the inlet end thereof for heating said particulate mixture within said die cavity to a temperature substantially above the softening temperature of said binder material but less than the softening temperature of said primary material; means external of said die cavity for continuously providing controlled pressure of between about 5 to about 400 psi to said heated particulate mixture within the die cavity during extrusion of the particulate mixture; and means in said die adjacent the extrusion end thereof for rapidly cooling said particulate mixture within the die cavity to below the softening temperature of the binder material to form a monolithic solid composite material whereby said substantially uniform particulate mixture is deformed, consolidated into a desired form and solidified in the extrusion die and is extruded from said die cavity as a solid composite porous article.