• Lobarinhas, Pam
• Teixeira, Jcf
• Teixeira, Sfcf

Abstract

In polymer processing by extrusion, the thermal behavior of the components downstream of the extruder dye is of great relevance to the final characteristics of the product. In fact, the process productivity, the product dimensional quality and the physical/mechanical properties are strongly dependent upon the cooling process. In the present work, a numerical model adequate to describe the thermal behavior of the calibrator and the polymer profile is developed and implemented as a computer code. The model is fully 3D, transient and includes a formulation for the polymer movement inside the calibrator based upon the VOF method [1]. Although for practical purposes, a steady solution is desired, the model was implemented as a transient case, to enable its accurate validation with experimental data. The interface between the extrudate and the calibrator is described through a coefficient for the thermal contact resistance. The equations were discretized in a finite volume formulation [2] and the code implemented in Fortran. The good agreement between the model and the experimental data has vindicated the accuracy of the computer model and its subsequent application in the analysis and optimization of complete calibration units. A parametric analysis for the most relevant variables, such as polymer velocity and calibrator length, demonstrated the consistency of the numerical model. Copyright © 2006 by ASME.

Topics

• impedance spectroscopy
• polymer
• extrusion