In the field of extruders is broadly divided into two types: single-screw extruders and twin-screw extruders. Both types of equipment have their own features and are widely used in the plastics and rubber industries. What are the advantages of these two extruders? What are the differences?

Structural differences

A single screw extruder has one screw and is simple. The screw is usually part of the cylinder, and the inside is smooth. A twin screw extruder has two screws. They can be arranged in different ways, such as parallel or conical. The barrel structure is often more complex and has a smooth inner wall. The barrel structure may be more complex and have special features on the inner wall.

Different working principles

(A) Material conveying

Single-screw extruder mainly relies on the friction generated by the rotation of the screw and the screw groove propulsion to transport the material, the material is easy to slip when the filling degree is low. Twin-screw extruder through the engagement of two screws and rotary movement, so that the material is subject to more powerful extrusion and propulsion, for high viscosity and other materials transport more effective.

(B) Plasticising and mixing

Single-screw extruder material driven by the screw through the compression section and homogenisation section plasticisation, mixing effect is limited. Twin-screw extruder two screws interact with each other, so that the material undergoes complex flow, plasticising and mixing more uniformly, and better dispersion of additives and so on.

Performance characteristics of the difference

(A) Production efficiency

A single-screw extruder is less efficient than a twin-screw extruder. Twin-screw extruders can run at high speeds, with high efficiency and good production.

(B) Mixing performance

A single-screw extruder can't mix well. A twin-screw extruder can mix materials well and is good for making products with more than one ingredient.

(C) Cleaning

A single-screw extruder is not very easy to clean. Twin-screw extruders have two screws that move in a meshing pattern, which makes them easy to clean.

(D) Precision

A single-screw extruder has limited precision, which affects the quality of the product. Twin-screw extruders can control pressure more accurately, for better results.

Different areas of application

A single-screw extruder is good for making some general plastic products like pipes and plates. The product doesn't need to be very high quality, and it can be made on a small scale.

Twin-screw extruders can be used to make high-quality plastic products. They are used to make special materials and high-performance products, such as engineering plastics, thermoplastic elastomers, and polymer composites. They are also used in reaction extrusion to control chemical reactions and improve product performance. The best type of extruder depends on what you want to make.