2002 Volume 14 Issue 12 Pages 821-827
Polymers form one of the most useful class of materials. In the processing of polymers, one must consider the interaction between flow behavior and temperature distribution due to their complex viscoelastic time dependent behavior. In this study, we investigated the effects of die length on the temperature distribution and the swelling ratio of capillary extrudates by using the streamline-upwinding finite element method. The non-isothermal Phan-Thien Tanner model proposed by Sugeng and Phan-Thien was used as a constitutive equation.
The temperature profile and the shape of extrudates are affected by the die length. The maximum temperature in the calculation region Tmax and the swelling ratio χf do not change in the low shear rate region. Tmax and χf increase with the die length in the high shear rate region. χf increases with Tmax when the dimensionless radial position of Tmax is near the centerline. However, χf decreases with an increase of Tmax when the dimensionless radial position of Tmax is near the wall.
