Solid conveying, compacting, melting and shear mixing extrusion of plastics are carried out through external power transfer and heat transfer of external heating elements. Since its birth, screw extruder has developed from ordinary screw extruder to new type screw extruder after nearly 100 years of development. Despite the variety of new screw extruders.
But as far as Dalian extrusion moulding is concerned, it is basically the same. The extrusion process of traditional screw extruder is realized by heating outside the barrel, friction force between solid material and barrel, screw and melt shear force. Friction coefficient, friction force, viscosity and shear stress are the main factors affecting the performance of traditional screw extruders.
意甲下注Because the factors affecting friction and viscosity are very complex, the extrusion process of traditional screw extruders is unstable and difficult to control, especially for some thermosensitive plastics with poor thermal stability and high viscosity. Since the 1960s, scholars from all over the world have done a lot of research on screw extrusion mechanism, and have made remarkable achievements.
However, their research is mostly confined to the extrusion mechanism, mechanical structure and energy transfer mode of traditional plastics, so they have not been able to make significant breakthroughs. A series of shortcomings of traditional screw extruders, such as huge volume, high energy consumption, high noise and difficult to improve product quality, have not been fundamentally solved.