Improved inverse design method for thin-wall hollow profiled polymer extrusion die based on FEM-CFD simulations

Extrusion process has excellent capability in continuous manufactures with high production volume, low cost, and steady quality for very complex cross-sectional products. However, manufacturing a proper extrusion die is challenging, but essential for qualified products, which needs to consider many influence factors in the die design. This paper shows an improved inverse design method for thin-wall hollow profiled polymer extrusion die by using computational fluid dynamics simulation. Also, the design criteria of the inverse design method for extrusion die are proposed and discussed. The simulation results show that the thickness of the die lip gap can be enlarged with the decreasing of the inlet flow rate. Additionally, it shows that the geometry profile of the die lip gap can be widened with the increasing of the length of the free jet. The analytical results have been verified by experiments and show a good agreement. It is concluded that the improved inverse design method with FEM-CFD simulations can provide better accuracy and significantly reduce the manufacturing difficulty of micro and thin-walled extrusion die.