Application of Computational Fluid Dynamics to Design of Polymer Extrusion Dies

Extrusion is one of the most widely used processes for polymer processing, e.g., producing film, pipe, sheet, cable and pellet. The shape of extrusion die has an important part for the manufacturing products. The purpose of this study has been to confirm the influence of nozzle shape on polymer flow. We calculated the die flow simulations in the various parameters. The calculation results are expected to improve the efficiency of pelletization. A commercial computer fluid dynamics program Ansys Fluent was used to calculate the die passage. The parameters for the calculations were taper angle, outlet diameter, properties of polymer and two models. The governing equations were the incompressible momentum equation and the continuity equation. As results, the increase in flow rate was confirmed by increasing taper angle and outlet diameter in the specific dimensional range. The average outlet velocity of single and multi-nozzle models almost corresponded in each same parameter.