| 摘要 |
The screw for an extruder for working plastic material and rubber comprises along its length several zones with different numbers of threads or webs. In at least one portion of its length, the screw has a plurality of single thread zones alternating with two-thread zones. In each of the two-thread zones there are two webs which are diametrically disposed and extend parallel to the axis of the screw. These axially extending webs have inclined or wedge shaped flanks so that a wedge shaped aperture is formed between the cylinder wall of the extruder and the wedge shaped flanks of the axially extending webs. One web of the two-thread zone joins the web of the preceding single thread zone and the other web of the two-thread zone joins the web of the following single thread zone at the points where the axially extending webs meet the webs of the two-thread zone. |
