Polymer extrusion: Further development of the mixing elements

In cooperation with the Institute for Polymer Extrusion and Compounding at the Johannes Kepler University in Linz (IPEC), KraussMaffei Berstorff has carried out scientific tests on mixing systems in several simulation series. The company is now using the consistently positive results of the investigation to optimize its single-screw extruders in view of the changing market requirements, with the primary aim being to further improve final product quality.

Basis for innovative and balanced mixer-element geometries

Screws with balanced mixing elements for the homogenization of the melt

"The investigation clearly shows that, with our philosophy put into practice over many years, we have our finger on the pulse of the manufacturers. The use of balanced mixing elements in single-screw technology has for many years been our main principle, because it guarantees the customer's manufacture of premium-quality products," says Dr.-Ing. Otto Skrabala, a development engineer at KraussMaffei Berstorff at the Munich location.

By means of numerical flow simulations, the influence of two elementary geometries on the feed and mixing process was examined. On the basis of these analyses, scientifically sound design strategies can be formulated. Thus, for example, factors such as the speed distribution in the flow channel, the pressure consumption or even the temperature have a decisive effect on the quality of the extrudate, and therefore also the end product. Perfect homogeneity can thus be achieved only through the use of balanced mixing elements.

"We will continually use the consistently positive results of the study in our development activities, with the primary aim of ensuring even higher product quality for the customer with the use of our single-screw extruder," concludes Dr. Skrabla.