| 摘要 |
PURPOSE:To uniformly plasticize a synthetic resin during the transportation period by using a screw extruder in which the flight of screw is discontinued at least one place and its ending and starting points are overlapped with each other. CONSTITUTION:Screw flights 51b, 52b, 53b, and 54b are orderly provided in a screw groove 5a provided in a screw 5 from its upstream side. And, in the structure, the upstream end starting point 52b of the flight 52b is positioned on the upstream side of the downstream end ending point 51c of the flight 51b, and in the circumferential direction, as shown by arrow, of the screw 5, the sarting point 52d is so designed that it is in cooperative or forward phase with ending point 51c. The same is true of the relations between the starting point 53d and the ending point 52c and between the starting point 54 and the ending point 53c. By overlapping the starting point and the ending point, the plasticization of synthetic resin can be uniformly attained because plasticized and unplasticized materials are well mixed with each other. |
