Modélisation du soufflage de gaine

The polymer film blowing process has been extensively studied in the literature. In most of the numerical models, the freezing line is arbitrarily fixed. In our anisothermal Newtonian and viscoelastic models, the freezing line is not set but results from the sharp increase of the viscosity. A precise computation of the bubble shape requires a careful determination of the initial angle of the bubble at the die exit. This has not been achieved yet. The existence of multiple solutions for the bubble and of an unattainable zone are underlined in the viscoelastic case.