Principle of Counter Rotating Twin Screw Extruder


Twin screw extruder has the characteristics of forced conveying, short residence time, good exhaust performance, uniform mixing and low power. Twin screw extruder is mainly composed of two mutually meshing screws rotating in the barrel, forcing the material to shear and move forward.

Below is the analysis of the working principle of the counter twin-screw extruder:


The two screws rotate in opposite direction, in which there are two cases: internal rotation and outward rotation. The situation of inward rotation is relatively small for the meshing of the two screw extruder with the opposite direction. This is mainly because of, if the thread of the feeding section is not fully meshed and not fully closed in the longitudinal and horizontal direction, the material is easy to form a pile between the radial clearance of the two screws and above the two screws, thus reducing the free space of the screw groove, and finally affecting the ability of the screw to accept the material from the feeder, not only affects the feeding performance of the screw groove, but also forms a bridge. Secondly, the material with radial clearance of two screws is rotated inward, and the reaction force will press the two screws towards the cylinder wall on both sides, which will accelerate the wear of screw and barrel. In the same way, the two screws of non meshing and non engaging two-screw extruder are inward rotating.


From the appearance, the thread direction of the two opposite rotating screws is opposite, one is left-handed, the other is right-handed, but they are symmetrical. When the material falls on the screw, it will quickly separate to both sides, fill the screw groove, transport forward, and quickly contact with the heat cylinder to absorb heat, which helps to heat and melt the material.

Above are the analysis of the working principle of the counter twin-screw extruder. If you need some help, welcome to contact us. Ningbo Fangli Technology Co., Ltd., as a manufacturer with a complete set of extruder production line equipment for nearly 30 years, we have a lot of equipment manufacturing experience. We will provide you with professional technical guidance, and give you some help of purchasing appropriate plastic extruder equipment.

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