| 摘要 |
The injection-moulding machines serve in particular for processing thermoplastic material with fillers. The non-return valve has a screw tip. Apart from the shank of the screw tip, there is an axially displaceable locking ring which, during the injection phase, bears against a spacing ring on the end face of the plasticising and injection screw and, during the plasticising phase, bounds with the body of the screw tip through-passages for the plasticised material entering into the plasticising space. The locking ring has in its bearing region against the body of the screw tip and in the complementarily designed bearing region for the spacing ring in each case an insert of ceramic material. In addition, the spacing ring may be a body of ceramic material. |
