| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem about sufficient mixing and extrusion in a uniform molten condition of molten resin, in a conventional screw for extruder.SOLUTION: A screw 1 for extruder of thermoplastic resin is configured so that: sub flights 13 are provided in grooves of main flights 11A continuous and adjacent each other on a measurement part M comprising the main flights 11A continuous from a main flight 11 of a compression part C; an interval between both side main flights 11A of the adjacent sub flights 13 is alternately changed between broad intervals W1, W3, W5 toward a screw tip end, and narrow intervals W2, W4,; and a groove depth of both grooves of the sub flight 13 is sequentially changed from small to large, and large to small, and the sub flights 13 have plural notches 13A with equal intervals or unequal intervals in the extension direction. Thereby, the molten resin is mixed on the measurement part M in a uniform state, and is extruded from the screw tip end.SELECTED DRAWING: Figure 2 |
