The screw extruder is one of the main equipment for plastic molding processing, which uses external power transmission and heat transfer from external heating elements to transport, compact, melt, shear, mix and extrude plastic solids.
Since its inception, screw extruders have undergone nearly a century of development and have evolved from ordinary screw extruders to new types of screw extruders. Although there are various types of new screw extruders, their extrusion mechanisms are basically the same.
The traditional screw extruder extrusion process is achieved through external heating of the barrel, friction between solid materials and the barrel, screw friction, and melt shear force. The “friction coefficient” and “friction force”, “viscosity” and “shear stress” are the main factors affecting the working performance of traditional screw extruders. Due to the complexity of factors affecting “friction” and “viscosity”, the extrusion process of traditional screw extruders is an unstable state that is difficult to control, especially for certain thermosensitive plastics with poor thermal stability and high viscosity.
Since the 1960s, scholars from various countries around the world have conducted extensive research on the mechanism of screw extrusion and have made significant achievements. However, due to their research being mostly limited to traditional plastic extrusion molding mechanisms, mechanical structural forms, and energy conversion methods, they have not been able to make significant breakthroughs. The shortcomings of traditional screw extruders, such as large volume, high energy consumption, loud noise, and difficulty in improving product quality, have not been fundamentally solved.
