Modeling of nonisothermal film blowing process for non‐Newtonian fluids by using variational principles

In this work, nonisothermal film blowing process analysis for non‐Newtonian polymer melts has been performed theoretically by using minimum energy approach and the obtained predictions were compared with both, theoretical and experimental data (internal bubble pressure, take‐up force, bubble shape, velocity and temperature profiles) taken from the open literature. For this purpose, recently proposed generalized Newtonian model depending on three principal invariants of the deformation rate tensor, D, and its absolute defined as $sqrt {D cdot D}$ has been used. It has been found that film blowing model predictions are in very good agreement with the corresponding experimental data. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011