Draw Resonance in Film Casting as a Response Problem Using a Material Description of Motion

A new numerical algorithm was developed for simulating one-dimensional, isothermal film casting of a viscoelastic polymer. The algorithm incorporates a material description of motion and allows the observation of draw resonance as a response problem. Simulation results for velocity, thickness, stress and stability for a low relaxation time agreed with the closed-form solutions for a viscous fluid. When the elastic contribution was increased the observed effects were as follows: the velocity decreased; the thickness gradient at the die increased; the thickness at the roll increased; the axial stress decreased; and the stability of the film decreased.