Numerical simulation of rheological behavior of polymer in three layer co-extrusion process

Abstract

The two-dimensional rheological models of the three-layer co-extrusion process for the generalized Newtonian fluid were established. Meanwhile, the flow characteristics of melts in the die channels were numerically simulated using the finite element method to explain the influence of the structure change of flow channels in the die section on the rheological behavior of melts. The simulation results indicated that the changes in the convergence angle of flow channels have certain impacts on the shift of the confluence interface of the three-layer co-extruded melt flow while little effects on the interface shape at the outlet. The flow ratio of the melt in each layer at the entrance has a significant effect on the interface shift. The flowing pressure of melts in the die is mainly determined by the inclination angle of flow channels while less influenced by the fact whether the inlets of the flow channels in each layer are smoothed or not.

Investigation of the Two-Channel Feedblock Zone in Co-Extrusion of Polymers

“…Geometry. The research was inspired by Wang and Mei's work on numerical simulation of coextrusion [7]. Feedblock with two channels with circular cross-section was designed.…”

Investigation of Co-Extrusion Using a Coat Hanger Die with Different Feedblock Cross-Section

“…The results from the combination of feed block and extrusion die will aid in the optimization of the geometry of the flow channel and the process parameters in the coextrusion die, enabling the selection of the best flow channel needed to achieve the intended level of geometric precision for the extrudate. Wang and Mei [5] investigated the flow of three-layered polymer extrusion in a feedblock part of a die, particularly, the influence of structure change of the inlet (or single layer) channels on the rheological behavior of the melts. They investigated effect of convergence angle, inflow rate ratio, transition zone shape and inclination angle of transition flow channel on pressure and velocity distribution and interface shift due to the change in each parameter.…”