Kneading and mixing machine

Claim 1

A continuously operable kneading and mixing machine for thermoplastic synthetic materials, comprising: (a) housing means formed with an inlet for the material and an outlet aperture for discharging plasticized material from the housing; (b) a mixing rotor rotatable in said housing means, said rotor including a screw conveying portion which extends over and thus covers said outlet aperture; (c) a throttling member in the form of a cylindrical sleeve mounted in said housing means adjacent the outlet end thereof and adapted to be selectively independently rotated relative to said rotor, said cylindrical sleeve extending closely but rotatably around at least the region of said screw conveying portion of said rotor which covers said outlet aperture, wherein the internal diameter of said cylindrical sleeve is the same as the internal diameter of said housing means surrounding said rotor thereby providing a continuous surface closely around said rotor for effecting the desired plasticizing of said material, said cylindrical sleeve being formed with a circumferentially limiting discharge orifice adapted to be longitudinally aligned with said outlet aperture, and (d) means for rotating said cylindrical sleeve so as to selectively align, partially align or disalign said discharge orifice with said outlet aperture, whereby the plasticized material can respectively freely pass through said outlet aperture, pass with restriction through said outlet aperture thereby increasing the retention time of and consequently the shear energy applied to the material, or be blocked altogether from passage through said outlet aperture.