Patent ID: 7566163

Claim:
A twin-screw extruder for mixing and dispersing a material to be kneaded into a kneaded product having a desired state of kneading and extruding the product from a tip end thereof, said extruder comprising: a barrel having two intercommunicating chambers and an extrusion opening at a tip end thereof; and a screw set mounted in each of said chambers so as to not completely mesh with one another, each of said screw sets comprising: a rotor segment comprising at least one kneading rotor, said kneading rotor having a plurality of kneading blades which provide a plurality of tip clearances different from each other at least in the circumferential direction, said kneading rotor having a constant sectional shape in the axial direction, as viewed in a section transverse to the axial direction, except for crest portions of said kneading blades; and a screw segment comprising at least one screw blade, said screw segment, except for crest portions of the screw blades thereof, having the same sectional shape as said at least one rotor segment comprising at least one kneading rotor, as viewed in a section transverse to the axial direction, except for the crest portions of said kneading blades.