Screw and head assembly for processing whole grains and cellulosic materials

In an extruder barrel assembly adapted to receive and convey a material:

• a tubular barrel section presenting on the interior thereof at least one relatively sharp cutting edge;
• a rotatable screw section disposed within said section and including an elongated body having means on the periphery thereof for pushing said material outwardly against said cutting edge during rotation of the screw section in order to subdivide said material,
• said means including structure defining a series of separate, circumferentially spaced, elongated grooves extending generally along the length of the body, said grooves progressively decreasing in depth from one side margin thereof to the other side margin.

An extruder screw section, comprising:

• an elongated, axially rotatable body having structure on the periphery thereof defining a series of separate, circumferentially spaced, elongated grooves extending generally along the length of the body, said grooves progressively decreasing in depth from one side margin thereof to the other side margin,
• said groove-defining structure including a series of generally radially oriented, elongated groove sidewall surfaces, and corresponding groove bottom wall surfaces joined thereto,
• said bottom wall surfaces extending from the joinder with the corresponding sidewall surfaces to the outer periphery of said body in a direction counter to the direction of rotation thereof.