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Numerical and Experimental Investigation of Elongational Viscosity effects in a Coat-Hanger Die

by PolyXtrue5,391 views

The flow in a coat-hanger die is simulated using the axisymmetric and planar elongational viscosities of a low-density polyethylene (LDPE) resin. Elongational viscosity is found to affect the velocity distribution at the die exit. Also, the predicted pressure drop in the die changed significantly when the effect of elongational viscosity was included in the simulation. However, elongational viscosity had only a minor effect on the temperature distribution in the die. Predicted pressure drop is compared with the corresponding experimental data.

Y. Sun, M. Gupta, J. Dooley, K. A. Koppi, M. A. Spalding, Journal of Plastics Technology, January 2008, Vol. 4, 1 – 14.

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PolyXtrue

Plastic Flow’s extrusion die design software, polyXtrue, is based upon a unique and proprietary theory that simulates flow of polymers taking into account not only the shear viscosity, but also the elongational viscosity of the polymer.  To simulate a multilayer flow during coextrusion, polyXtrue uses a newly developed algorithm, called Mesh Partitioning Technique, which allows coextrusion simulation without changing the finite element mesh as the shape of different polymer layers change during simulation.  Thereby, allowing simulation of the flow even in highly complex coextrusion dies.

http://plasticflow.com/

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