Tuning of Mixing Zone Parameters in a Dynamic Mixer and Performance Comparison with Screw-based Mixers

Abstract

A new dynamic mixer has been designed for the mixing of two incompatible polymer melts. Three main design parameters (number of circles of holes (N), number of holes (M) per circle, and diameter of the holes (d₃)) for the mixing zone of the dynamic mixer were selected to study their influences on the pressure drop (Δp) and the segregation scale (S) using Orthogonal tests. The influences of flow rate and rotational speed were also investigated. In addition, the mixing effect was compared with that of screw and slotted-screw mixers. The results showed that the most significant factor influencing S and S∙Δp is N. Both Δp and S increased with increasing flow rate, and decreased with increasing rotational speed. Compared to the screw and slotted-screw mixers, the dynamic mixer had a better mixing effect and shorter length.