The conical twin screw is different from the parallel t […]
The conical twin screw is different from the parallel twin screw in appearance. Its two ends have different diameters. The diameter of the feeding section is large, while the diameter of the homogenization section is small, and the middle is gradually transitioned. The conical twin-screw is an intermeshing type, and most of them are counter-rotating. Two conical screws mesh with each other in the barrel and rotate in opposite directions, and there is a reasonable clearance between the top of the spiral edge of one screw and the root of the other screw. Due to the counter-rotation, the spiral path of the material on one screw is blocked by the other screw, and the material can only move axially through the gaps in each part under the push of the screw.
When the material passes through the radial gap between the two screws, it is like passing through the nip of two rollers, and the stirring and shearing are very intense. Therefore, the plasticization of the material is very uniform, which is especially suitable for processing PVC plastics. The compression ratio of the conical twin screw is not only formed by the screw groove from deep to shallow, but also formed by the outer diameter of the screw from large to small, so the compression ratio is quite large, so the material is plasticized in the barrel more fully, More uniform, to ensure the quality of the product. In this way, under the premise of ensuring quality, the rotation speed of the extruder can be increased, thereby increasing the production capacity of the extruder.