Cooker-extruder apparatus and process for cooking-extrusion of biopolymers

A cooker-extruder for the production of thermally treated bio-polymers, comprising:

• an extrusion cylinder having an exit end;
• a feeding hopper attached to said extrusion cylinder;
• an exit nozzle attached to said exit end of said extrusion cylinder;
• and
• a plurality of spatula-pumps disposed within said extrusion cylinder and arranged between said feeding hopper and said nozzle, each said spatula pump comprising a plate with a matrix of holes and at least one spatula element, said spatula element being passable over said plate with a matrix of holes, said plurality of spatula-pumps being serially oriented with respect each other.

A process for cooking extrusion of biopolymers comprising:

• placing a biopolymeric material to be extruded in a cooker extruder having a screw, and at least one spatula pump, said spatula pump comprising a plate with a matrix of holes and at least one spatula element, said spatula element being passable over said plate with a matrix of holes;
• extruding the biopolymeric material through the cooker-extruder;
• and
• passing said spatula element over said plate with a matrix of holes to cause a pressure increase and thus a liquefaction of fluid vapor generated from said biopolymeric material in front of said passing spatula element and to cause a decrease in pressure behind said passing spatula element, thereby allowing an evaporation of the fluid contained in the biopolymeric material.