Analysis of Damageable Parts and Structure of Co-rotating Parallel Twin Screw Extruder

1. The damageable parts of the co-rotating parallel twin screw extruder

If there are fillers such as calcium carbonate and glass fiber in the material produced by the crusher, it may accelerate the wear of the screw and barrel of the co-rotating parallel twin screw extruder.

Because the material is not plasticized evenly, or there is metal foreign matter mixed into the material, the torque of the screw rotation suddenly increases. This torque exceeds the strength limit of the dual screw extruder, causing the screw to be twisted off, which is an unconventional accident.

The screw rotates in the barrel, and the friction between the material and the two gradually wears the working surface of the screw and the barrel: the diameter of the screw gradually decreases, and the diameter of the inner hole of the barrel gradually increases. In this way, the matching diameter gap between the screw and the barrel increases little by little with the gradual wear of the two.

However, since the resistance of the head and the spreader plate in front of the barrel has not changed, this increases the leakage flow of the extruded material when it advances, that is, the flow of the material from the diameter gap to the feeding direction increases, resulting in declined production of the dual screw extruder. This phenomenon increases the residence time of the material in the barrel, resulting in the decomposition of the material. In the case of polyethylene, the hydrogen chloride gas generated by the decomposition enhances the corrosion of the screw and barrel.

The combined working quality of the two parts, the screw, and the barrel have an important influence on the plasticization of the material, the quality of the product, and the production efficiency. When the two parts are seriously worn and the output of the dual screw extruder decreases, the maintenance of the screw and barrel should be arranged.

2. Structural analysis of the co-rotating parallel twin screw extruder

(1) Intuitively understand the wear of the damageable parts of the co-rotating parallel twin screw extruder. Because it is easy to open, the wear degree of the threaded components and the lining of the barrel can be found at any time, to carry out effective maintenance or replacement.

(2) It has a wide range of applications and can be applied to the processing of various materials.

(3) Reduce the production cost. When changing the color of the twin screw extruder, it only takes a few minutes to quickly open the barrel and perform manual cleaning, so that no or less cleaning material should be used, which saves costs.

(4) High torque and high speed. At present, the development trend of twin screw extruders in the world is to develop in the direction of high torque, high speed, and low energy consumption. The boon brought by high speed is high productivity.

(5) High output, high quality, and high efficiency. With other advantages of ordinary twin screw extruders, it also can achieve high output, high quality, and high efficiency.

(6) Improve labor efficiency. During equipment maintenance, for ordinary twin screw extruders, operators often have to remove the heating and cooling systems first, and then extract the screw as a whole. In terms of the split-type twin screw extruders, operators just need to loosen a few bolts, turn the handle device of the worm gearbox to lift the upper half of the barrel to open the entire barrel, and then carry out maintenance. This not only shortens the maintenance time but also reduces the labor intensity.