Abstract
The flow behavior of polymer melts within a slit die is an important consideration when designing a die geometry. The quality of the extruded polymer product can be determined through an evaluation of the flow homogeneity, wall shear rate and pressure drop across the central height of the die. However, mathematical formulations cannot fully determine the behavior of the flow due to the complex nature of fluid dynamics and the nonlinear physical properties of the polymer melts. This paper examines two slit die geometries in terms of outlet velocity uniformity, shear rate uniformity at the walls and pressure drop by using the licensed computational fluid dynamics package, Ansys POLYFLOW, based on the finite element method. The Carreau-Yasuda viscosity model was used for the rheological properties of the polypropylene. Comparative analysis of the simulation results will conclude that the modified die design performs better in all three aspects providing uniform exit velocity, uniform wall shear rates, and lower pressure drop.
Original language | English |
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Pages (from-to) | 111-125 |
Number of pages | 15 |
Journal | Advances in Computational Design |
Volume | 5 |
Issue number | 2 |
DOIs | |
Publication status | Published - Apr 2020 |
Keywords
- Ansys POLYFLOW
- Carreau-Yasuda viscosity model
- Coat-hanger dies
- Flow homogeneity
- Polymer
- Pressure drop
- Sheeting dies
- Slit dies
- Three-dimensional FEM simulations
ASJC Scopus subject areas
- Computational Mechanics
- Computer Graphics and Computer-Aided Design
- Computational Mathematics