EFFECT OF OPERATING CONDITIONS ON THE MIXING PERFORMANCE OF THE SCREW ELEMENT AND THE KNEADING BLOCK IN A TWIN-SCREW EXTRUDER

摘要

By virtue of tracking the motion of particles in the right-hand screw element and kneading discs, the effect of operating conditions on the residence time, total shear strain, and the mixing coefficient was analyzed using a 3 D numerical study. The calculated RTD of the screw element was verified by an experimental result. The simulation results implied that the flow rate has stronger effect on the mixing performance than the rotating speed judging from the mixing coefficient G, residence time distribution and total shear strain. When the rotating speed changes and the axial pressure difference remains constant, the total shear strain and the mixing coefficient varies little.