The use of circular materials (recycled polymers) within the field of extrusion is difficult due their often-inconsistent viscosity related to variations in composition and molecular weight of the recycled polymers. Such variations lead to fluctuations in die pressure and flow balance, necessitating continuous adjustments in the extrusion process. Our study explores the use of ultrasonic vibrations to regulate extrusion die pressure, aiming to improve the quality of recycled plastic profiles.
Employing Ansys CFD, we investigated the complex interaction of ultrasonic waves within extrusion dies, focusing on their impact on a non-Newtonian polymer melt. The presence of shear and pressure waves in a non-Newtonian polymer melt leads to shear thinning, effectively reducing die pressure. Consequently, this leads to more precise and effective pressure control within the die. The ultrasonic waves have a short penetration depth, which allows for local control of the flow resistance and therefore potentially flow balancing. This results in a more uniform and optimized extrusion process, highlighting the potential for improvements in the extrusion of recycled polymers.