CFD analysis of ultrasonic vibrations to enhance recycled polymer extrusion efficiency

Abstract

The use of recycled polymers within the field of extrusion is difficult due to their often inconsistent viscosity related to variations in composition and molecular weight. Such variations lead to fluctuations in die pressure, requiring continuous adjustments in the extrusion process. This study explores the use of ultrasonic vibrations to regulate extrusion die pressure, aiming to improve the quality of recycled plastic profiles. Employing Ansys CFD, the ultrasonic waves within extrusion dies were investigated, focusing on their impact on a non-Newtonian polymer melt. The presence of shear and pressure waves in a non-Newtonian polymer melt lead to shear thinning, effectively reducing die pressure. This allows for more precise and effective pressure control within the die. The CFD simulations of the effect of ultrasonic vibrations on the polymer melt as demonstrated in this study may benefit the die design process, addressing the challenges of inconsistent viscosity in recycled polymers and optimizing their extrusion process.