Advances in Computational Design

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A comparative analysis of sheeting die geometries using numerical simulations

  • Igali, Dastan (Department of Mechanical & Aerospace Engineering, School of Engineering & Digital Sciences, Nazarbayev University) ;
  • Wei, Dongming (Mathematics Department, School of Sciences and Humanities, Nazarbayev University) ;
  • Zhang, Dichuan (Department of Civil & Environmental Engineering, School of Engineering & Digital Sciences, Nazarbayev University) ;
  • Perveen, Asma (Department of Mechanical & Aerospace Engineering, School of Engineering & Digital Sciences, Nazarbayev University)
  • Received : 2019.08.28
  • Accepted : 2019.10.27
  • Published : 2020.04.25
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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.

Keywords

Acknowledgement

Grant : Development and Prototyping of Extrusion Dies for Advanced Plastic Sheets and Thin Film Production

Supported by : Ministry of Education and Science of the Republic of Kazakhstan

This research was funded under the target program No AP05134166 "Development and Prototyping of Extrusion Dies for Advanced Plastic Sheets and Thin Film Production" from the Ministry of Education and Science of the Republic of Kazakhstan.

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