Author(s)

Chongxin Wang, Xiangzhe Zhu

Corresponding Author

Chongxin Wang

ABSTRACT

Screw extruder is an important equipment for mixing processing. This paper briefly introduces the physical models of novel tri-screw and four-screw extruders. Using the software Polyflow, the three-dimensional transient finite element models are employed to explore the complex flow and mixing characteristics of polymer fluids in tri-screw and four-screw extruders. The mixing index of particles distributed in the special center regions of tri-screw and four-screw extruders are analyzed specially. Moreover, the statistical post-processing, software of Polystat, is used to calculate the mixing index probability distribution, time-averaged mixing efficiency, instantaneous time mixing efficiency, logarithmic stretching rate, shear rate and axial distance mixing index. Parameters mentioned before between the four-screw, twin-screw and tri-screw extruders are compared in order to better understand the mixing mechanism of the novel four screw extruder. The results show that the mixing efficiency of the four-screw extruder is better than that of the twin-screw extruder and the tri-screw extruder.

KEYWORDS

Tri-screw extruder, four-screw extruder, mesh superposition technique, mixing efficiency