An experimental and theoretical studies in two-component stratified converging flow of polymer melts were presented. Mathematical modeling and simulation were carried out to investigate the effect of converging angle on the interface distortion in the equilibrium and transient region, and the experimental analysis of the interface distortion was compared with the theoretical prediction. In the equilibrium region, the results of comparison showed the same trend qualitatively.
In the experiment, the interface shape of cross section of extrudate bended toward low viscous component. The ratio of thickness of high viscous component to total thickness was measured, which was called as an interface distortion. As increasing converging angle, the interface distortion increased and the line of flat interface became shorten. In addition, when the volumetric flow rate ratio of high viscous component to low viscous component increased, the interface distortion was increased, and the line of flat interface became longer. Also, it was less sensitive to flow rate ratio when converging angle was increased.
The results of the present theory for the effect of converging angle and flow rate ratio showed the same trend as the experimental results, and theoretical transient solution was developed. As decreasing converging angle, the transient region from the inlet to the equilibrium state was decreased. The region may be that the converging plates became more parallel with the decrement of converging angle.