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How does a plastic extruder work?
The screw extruder is one of the main equipments for plastic molding processing. It uses solid power transportation, compaction, melting and shear mixing extrusion molding of plastics through external power transmission and heat transfer from external heating elements. Since the birth of the screw extruder, after nearly a century of development, it has developed from an ordinary screw extruder to a new type of screw extruder. Although there are many types of new screw extruders, they are basically the same in terms of the extrusion mechanism. The extrusion process of the traditional screw extruder is achieved by external heating of the barrel, friction between solid materials and the barrel, screw friction and melt shearing force. "Friction coefficient" and "friction force", "viscosity" and "shear stress" are the main factors affecting the working performance of traditional screw extruders. Due to the complex factors affecting "friction" and "viscosity", traditional screw extrusion The extruder extrusion process is an unstable state and difficult to control. It is particularly prominent for some thermally sensitive plastics with poor thermal stability and high viscosity. Since the 1960s, scholars from various countries around the world have done a lot of research on the screw extrusion mechanism and have made significant achievements, but because their research is mostly limited to traditional plastic extrusion molding mechanisms, mechanical structure forms and energy conversion methods, There has been no major breakthrough. A series of shortcomings of the traditional screw extruder, such as large volume, high energy consumption, high noise, and difficult to improve product quality, have not been fundamentally solved.