Working principle of twin screw extruder
Although the structure of the twin screw extruder is very similar to that of a single screw extruder, there are great differences between them in operating principle. In the single screw extruder, the power of material moving forward mainly depends on the difference of friction coefficient between material, barrel, and screw. If, the friction coefficient of material and machine barrel inner wall is too small, when screw rolling, the material will hold screw rolling together, so that thread can not play its role in promoting, the material can not be transported forward.
Because the twin-screw extruder has made the material in the twin-screw retention time is short and uniform, not easy to produce local degradation transformation characteristics, this processing material retention time will be long thermal decomposition, curing or agglutination of heat-sensitive plastic, such as PVC material coloring, mixing, product production has a common advantage.
Because of the excellent mixing and plasticizing characteristics of the twin-screw extruder, it is mainly used for polymer modification, such as blending, filler, enhanced extrusion, and other operations, but also can directly extrude plate, pipe, profile and other products.
The twin screw extruder has a wide range of applications, can be applied to the processing of a variety of materials, can complete high yield, high quality, high efficiency, and other characteristics, although its structure is more complex, it is still widely attention and rapid development.
In recent years, with the development of new fields, new products, and new technologies such as synthetic data and fine chemical industry, more and more special or special conditions of polymers to be processed are needed, which makes the application of twin screw extruder more and more extensive. At present, the world twin screw extruder is the trend to high torque, high speed, low energy consumption direction.