The twin-screw extruder barrel is an important part of the extruder in the extrusion compression molding system. The barrel and the screw work together, the barrel contains the screw, and the screw rotates in the barrel. When the screw rotates to push the plastic forward in the barrel, the heat is transferred from the outside of the barrel to the plastic in the barrel. In addition, the thread volume on the screw gradually shrinks, causing the plastic in the thread groove to be squeezed, turned and sheared. After being uniformly mixed and plasticized under the action of various forces such as cutting, it gradually melts into a viscous flow state while moving toward the front of the barrel, completing the plasticization of the plastic. The normal cooperation between the barrel and the screw ensures the continuous extrusion of raw materials by the extruder.

Advantages of twin-screw extruder

1. Good self-cleaning properties. There is a speed difference at the meshing point between the twin screws. Under mutual friction, the occurrence of material stagnation can be reduced, and the self-cleaning properties of the co-rotating twin screws are stronger.

2. Easy to observe. It is easy to open, so the wear degree of threaded components, barrel inner bushings and other components can be observed at any time, so that timely and effective replacement can be carried out to avoid product waste caused by component damage.

3. Reduce production costs. The openable processing area gives it great advantages in product color and material changes. And the mixing process can be analyzed by observing the melt profile along the entire screw.

4. Improve labor efficiency. When performing mechanical maintenance, it is usually necessary to remove the heating and cooling systems first, then twitch the screw, remove the necessary bolts and turn the turbine box handle device to lift the upper part of the barrel, and then the barrel can be opened for repair. It not only saves time and reduces the labor intensity of maintenance workers, but also reduces production interruptions caused by equipment wear.

5. High torque and high speed. By observing development trends, we can see that this field is currently developing in the direction of high torque, high speed, and low energy consumption. For example, the productivity improvement brought by high rotation speed makes it more suitable for the production and processing of high-viscosity and heat-sensitive materials.

6. High yield and high quality. Compared with single-screw extruders, it performs better in solid and melt transportation of materials, and because the joint operation of twin-screws mixes materials more fully, it has the advantages of high output, high quality, and high efficiency.

7.Wide range of applications. It has good general adaptability to different materials, so it can be suitable for processing a variety of materials.

The structure of the twin-screw extruder barrel is relatively simple. In large extruders, the structure of the barrel can be composed of several segments. Since the barrel is divided into several sections, the length of each barrel section is reduced, which brings convenience to the mechanical processing of the barrel. However, for this kind of barrel composed of several sections, it is difficult to achieve the same accuracy of the inner diameter after machining and the concentricity accuracy of the inner holes of the barrels of several sections; in addition, the segmented barrels are connected with flanges, which increases the heating and cooling of the barrel. The layout of cooling equipment will also bring some difficulties, and the temperature control will not be too uniform. In order to save more expensive alloy steel, the barrels of some large extruders use bushings in the inner holes or casting a wear-resistant alloy layer. Such a barrel outer casing can be cast from ordinary steel to reduce the manufacturing cost of the barrel.