Abstract: Flow field simulation of WPC/supercritical CO2(WPC/Sc-CO2) composites flowing through an extrusion foaming die with different die dimension were performed by FEM software Polyflow, and the effects of foaming die dimension on the cell nucleation of WPC/Sc-CO2 composites were investigated. It was found that increasing the capillary length of the foaming die had little effect on the pressure drop rate and the distance from cell nucleation point to die exit. By decreasing the capillary diameter of the foaming dies, a large pressure drop rate was created, and the cell nucleation point location moved toward the die exit.

Key words: wood-plastic composite, supercritical fluid, cell nucleation, numerical simulation