The special design of extrusion head for manufacturing of polymer pipes with increased mechanical strength

摘要

This work presents a proposal of the new design of an extrusion head for polymer pipes manufacturing, especially from polyethylene. The most significant feature of this head is that the conical core of the conical nozzle and the nozzle port of the core have on their surfaces coils made along a helical path which are shifted relatively to each other. As a result, the channel created between these parts contributes to helical twisted polymer flow. Helical flow causes tangential stresses which is a result of the orientation of the macromolecules in the flow direction. This makes that the pipe has increased strength to internal pressure. This current state of knowledge of this kind of extrusion heads and the mathematical interpretation of increasing the strength of the polymer pipes during the extrusion process were also presented. The proposed new extrusion head allows the production of polymer pipes with increased mechanical strength using a very easy and inexpensive method.