Paper Number
VP8
Session
Pre-recorded Flash Presentations (virtual)
Title
Die shape optimization for extrudate swell using feedback control
Presentation Date and Time
All Week (Asynchronous) Any Time
Track / Room
Pre-recorded Presentation / Virtual
Authors
- Spanjaards, Michelle (Eindhoven University of Technology, Polymer Technology)
- Hulsen, Martien A. (Eindhoven University of Technology, Polymer Technology)
- Anderson, Patrick D. (Eindhoven University of Technology)
Author and Affiliation Lines
Michelle Spanjaards, Martien A. Hulsen and Patrick D. Anderson
Eindhoven University of Technology, Eindhoven, The Netherlands
Speaker / Presenter
Spanjaards, Michelle
Keywords
computational methods; non-Newtonian fluids; polymer melts
Text of Abstract
Extrusion is a widely used process to create products with a fixed cross-sectional profile. Many applications require cross-sections of complex shapes, where the dies contain sharp corners. Common requirement on the extrudate is dimensional precision. The dimensions of the extrudate are highly influenced by extrudate swelling. The swelling process involves complex dynamics influenced by many parameters, such as viscoelasticity and temperature. Therefore, the optimized shape of a die, to obtain an extrudate with desired dimensions and shape, is now often obtained through trial-and-error.
We developed a transient 3D finite element model, to predict extrudate swelling for extrudates containing sharp edges. This model describes the corner lines of the domain separately to obtain the positions of these lines in the two swell directions. A 2D height function is used to describe the free surfaces of the extrudate, using the positions obtained from solving the material lines to expand the domain of the height function [1].
A novel approach to solve the inverse problem of three-dimensional die design for extrudate swell is developed, using a real-time active feedback control scheme. In this talk we show the validity of this method by showing optimization results for 2D axisymmetric extrusion flows of a viscoelastic fluid for different Weissenberg numbers. Finally, we show that this method is able to obtain the desired extrudate shape in 3D for extrudates of a viscoelastic fluid for different Weissenberg numbers and different amounts of shear-thinning.
[1] M.M.A. Spanjaards, M.A. Hulsen, P.D. Anderson. Journal of Non-Newtonian Fluid Mechanics, 270:79-95, 2019