| 摘要 |
The invention relates to multi-screw extruders and provides a self-cleaning type extruder including a cylinder (2) and at least two screws (1,1 min ) therein adapted to rotate in the same directions, said screws (1,1 min ) being in such a relation that at any position in at least a part of the screws (1,1 min ) which lies in the longitudinal direction of the extruder, the contour of one screw in a cylinder cross-section taken at right angles to the screw axes is in substantial contact at one point with the contour in the same cross-section of another screw intermeshing therewith; wherein each of said screws (1,1 min ) has at least two screw flights (3, 5; 3 min , 5 min ), and the top (4,4 min ) of at least one of the screw flights (3,3 min ) is substantially in contact with the inner wall surface of the cylinder and the top (6,6 min ) of at least one other screw flight (5,5 min ) has a predetermined tip clearance (8) with respect to the inner wall surface of the cylinder (2). |
