Steps for the Optimization of Pipe and Tubing Extrusion Dies

J.R. Puentes[1], T.A. Osswald[1], S. Schick[2], J. Berg[2]
[1]Polymer Engineering Center, University of Wisconsin, Madison, WI, USA
[2]TEEL Plastics, Baraboo, WI, USA

The extrusion of polyolefin pipes suffers degradation due to mechanical design problems of the extrusion die that is commonly used. This study uses numerical and computational approaches to detect problematic areas in the die geometry. Simulations show that in the conventional die there are areas of stagnation and recirculation of the melt flow, resulting in greater residence times, one of the main causes of degradation. This study introduces the use of novel profiles which reduce stagnant regions, recirculation events, and can optimize the extrusion process. Additionally, this study introduces a methodology based on residence time distribution (RTD), a parameter that can be applied in extrusion and injection molding optimization of the tooling and equipment.