What Is A Twin Screw Extruder？

January 05, 2023

What Is A Twin Screw Extruder？

High quality twin screw extruder is developed on the basis of Single Screw Extruder. Because of its good feeding performance, mixing and plasticizing performance, exhaust performance, extrusion stability and Other characteristics, it has been widely used in the molding of extruded products.

The twin screw extruder is composed of several parts, such as transmission device, feeding device, barrel and screw, etc. The function of each part is similar to that of the single screw extruder, and the performance is good. The difference with the single screw extruder is that the twin screw extruder has two parallel screws placed in the "∞" section of the material.

High quality twin screw extruders used for profile extrusion are usually closely engaged and cross-rotating, although a few also use co-rotating twin screw extruders, which generally operate at relatively low screw speeds of about 10 r/min. High speed meshing co-rotating twin screw extruder, used for mixing, exhaust or as a continuous chemical reactor, the maximum screw speed range of this kind of extruder is 300-600r/min, good performance. The non-meshing extruder is used for mixing, venting and chemical reaction, and its transport mechanism is very different from that of the meshing extruder, which is close to that of the single screw extruder, although there are essential differences between the two.
Good Performance Twin Screw Extruder

From the principle of motion, high quality twin screw extruder in the same meshing and different meshing and non-meshing type is different, but the performance is good.
1. Co-meshing twin screw extruder
This type of extruder is available in low speed and high speed, the former is mainly used for profile extrusion, while the latter is used for specialty polymer processing operations.
(1) Close meshing extruder. The low-speed extruder has a closely meshing screw geometry, in which the edge shape of one screw is closely matched with the edge shape of the other screw, that is, the conjugate screw shape.
(2) Self-cleaning extruder. The high speed co-direction extruder has a closely matching screw edge shape. The screw can be designed to have a fairly small screw clearance, so that the screw has a closed self-cleaning effect, this kind of twin screw extruder is called a close self-cleaning co-rotating twin screw extruder.
2. Cross-meshing twin screw extruder
The gap between the two screw grooves of the closely meshing counterrotating twin screw extruder is very small (much smaller than the gap in the co-meshing twin screw extruder), so that the forward conveying characteristics can be achieved.
3. Non-meshing twin screw extruder
The center distance between the two screws of the non-meshing twin-screw extruder is greater than the sum of the radii of the two screws.

Author:

Ms. Lily Li

E-mail:

sales@batten-machinery.com

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8618605800326