Numerical Simulation of Flow Characteristics of Co-Rotating Intermeshing Four-Screw Extruder

The flow of polypropylene melt in new-style four-screw extruder was analyzed using the finite element method (FEM). The pressure and velocity fields in a flight element of co-rotating intermeshing four-screw extruders were calculated. A special study of flow in the central region was employed by analysis of the velocity, pressure and resident time distribution (RTD). The extrusion characteristics of the four-screw extruder were calculated and compared with a twin-screw extruder, `-' arrayed tri-screw extruder and triangle arrayed tri-screw extruder. The results show that the pressure and velocity gradient of the material in the four intermeshing regions is larger than that in the barrel channel. There is one circumfluence in central region which prolongs RTD in the central region and reduces the ability of pressure generation for the four-screw extruder. The material in the central region cannot stagnate. The mixing efficiency of the four-screw extruder is better than that of the twin-screw extruder and tri-screw extruder.