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The Main Advantages and Disadvantages of Twin Screw Extruder

The Main Advantages and Disadvantages of Twin Screw Extruder

Simply put,  twin screw extruder is a machine composed of two identical screws, which have penetration and self-cleaning functions. They are installed on a shaft and run continuously in a fixed closed shell called a "barrel" in the same direction as the twin-screw extruder, and the residence time is very short.


Jump to an Introduction of Twin Screw Extruder

Advantages of Twin Screw Extruder

1. Good self-cleaning

There is a speed difference in the meshing between the twin screws. Under mutual friction, the occurrence of material stagnation can be reduced, and the self-cleaning property of the same-rotating twin screws is stronger.

2. Convenient to observe

The twin-screw extruder machine is easy to open, so that the degree of wear of the threaded elements, the inner liner of the barrel and other components can be observed at any time, so that timely and effective replacement can be performed to avoid product waste caused by component damage.

3. Reduce production costs

The openable processing area makes the twin-screw extruder have greater advantages in product color change and material change. And the mixing process can be analyzed by observing the melt profile on the entire screw. Ordinary twin-screw extruders need to use a large amount of cleaning material to clean the machine, but in some split twin-screw extruders, the barrel can be quickly opened for manual cleaning, which reduces the use of cleaning materials.


4. Improve labor efficiency

When performing mechanical maintenance, the heating and cooling system of the ordinary twin-screw extruder usually needs to be removed first. In the twitch screw and split twin-screw extruder, it is only lifted by removing the necessary bolts and turning the turbine box handle device. The upper half of the barrel can be opened to 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 speed

By observing the development trend of twin-screw extruders, we can see that this field is currently developing in the direction of high torque, high speed, and low energy consumption. For example, the increase in productivity brought about by high speed is especially reflected in the split twin-screw extruder, making it more suitable for the production and processing of high-viscosity, heat-sensitive materials.

6. High yield and high quality

Compared with the single-screw extruders, the twin-screw extruder, especially the intermeshing twin-screw extruder, performs better in the solid and melt conveying of the material, and due to the joint operation of the twin screw, the mixing of the material is more sufficient. Therefore, it has the advantages of high output, high quality and high efficiency.

Disadvantages of Twin Screw Extruder

1. The problem of the high discharge rate bearing device has not been dealt with; 

2. In the meshing zone, especially in the shrinking section, the barrel and the screw edge are severely worn; 

3. The screw and barrel of the meshing conical twin-screw extruder have relatively high processing costs; 

4. The heat generated in the barrel is small, and most of the heat is introduced from the heater outside the barrel.

Twin Screw Extruder Screw Design

1. Sealing part

The first screw element of the screw is used to convey and prevent materials from coming out of the screw.


2. Main feeder

The large pitch and force-transmitting screw elements ensure that the material is transported to the next melting section. The combination of large, medium and small pitches ensures that the material is conveyed quickly, and then the speed is reduced to compress the material and fill the screw to prepare for compounding.

3. Kneading part (melting & compounding)

Preliminary mixing is accomplished through different combinations of kneading elements.


4. Natural exhaust

Use large pitch conveying elements. It must use the left-handed screw element in front of the exhaust port to form a material reflux and form a high pressure to remove volatile impurities, gas and steam.


5. Feeding section of side feeder

It is used to add suitable materials to molten polymers.

Large pitch conveying elements are used for fast conveying. And use small pitch elements to compress the material before the side feeder.

The material is generally glass fiber, carbon fiber or filler material.


6. Kneading part (compound)


7. Vacuum degassing port

Use a pump to remove volatile impurities, gases and vapors from molten materials.

Use large pitch conveying elements. It must use a left-handed screw element in front of the exhaust port to form a material reflux and form a high pressure.


8. Measure the pressure part to extrude material

Application of Twin Screw Extruder

Twin screw extruders have high production efficiency and low power consumption; therefore, they are suitable for many industries. They can be used to make PVC profiles and PVC composite materials, different pipes, plates, profiles and soft and hard PVC pellets.

They can also be used in the polymer, chemical and food industries to mix various consumer products, such as:





soap bar




Food and feed products

Cellulose pulp

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