Twin-screw continuous kneading apparatus and kneading method using the same

Abstract

A twin-screw continuous kneading apparatus is provided which can stably supply an additive without reducing the production capability and greatly increase the throughput of a high-quality compound. The kneading apparatus includes a second supply unit connected to an upstream end or a midstream portion of a barrel and supplying an additive into kneading chambers, and has a kneading zone provided by a part of each of kneading screws downstream of the second supply unit for mixing the additive into a kneaded material. The kneading zone is constituted by a segment group made up of a plurality of rotor segments arranged successively in an axial direction of the kneading screw, the segment group satisfying conditions (a) the segment group comprises only feed segments having flights twisted in a direction to feed the kneaded material downstream with rotation of the kneading screw, or comprises the feed segments and neutral segments having flights parallel to the axial direction, and (b) each of the rotor segments making up the segment group has flights formed by arranging a high-height tip portion providing a comparatively small tip clearance relative to an inner wall surface of the kneading chamber and a low-height tip portion providing a comparatively large tip clearance alternately in the axial direction in succession.