The twin-screw extruder can be divided into two types of co-rotating and counter-rotating according to the direction of screw rotation, and reverse rotation can be divided into two types: inward and outward. The pressure zone of co-rotating twin-screw has different properties, and the material is in The inner cavity of the sleeve is affected by the rotation of the screw to produce a high pressure zone and a low pressure zone. That is how to achieve high efficiency.

Obviously, the material will flow from the high-pressure zone to the low-pressure zone in two directions: one is that the wear of the square screw is reduced as the screw rotates, and the material is conveyed, sheared, mixed and heated by the barrel shell. , Under the action of high pressure, it is matured and is squeezed out of the barrel.

The counter-rotating twin-screw extruder generally uses two screws with exactly the same size but opposite thread directions. The difference between inward rotation and outward rotation is that the position of the pressure zone is different, and the pressure generated by the inward rotation of the twin screw is higher and lower. Low, when the material passes through the twin screw, an extremely high pressure will be generated at the inlet, causing difficulty in feeding. At present, this inward and reverse rotation is rarely used; the pressure generated by the outward rotation of the twin screw is high and low, which is beneficial Feeding. But compared with the reverse rotation and the same rotation, the C-shaped material flow formed in the screw cannot move from one screw to the other, and the degree of mixing of the material is significantly reduced, and its self-cleaning ability is also No co-rotating twin screws are effective and stable.

　　The above is the relevant knowledge of the working principle of the twin-screw extruder. At the same time, the twin-screw extruder and the single-screw extruder have their own advantages and can be selected mainly according to the processing materials and the strength of the enterprise.