What is a twin screw barrel and how does it function in an extruder?

A twin screw barrel is a key component of an extruder machine used in various industries for processing materials such as plastics, rubber, and food products. It consists of two intermeshing screws housed within a cylindrical barrel. The screws rotate in the opposite direction to each other, creating a meshing or interlocking effect.

The function of a twin screw barrel in an extruder is to facilitate the mixing, kneading, conveying, and melting of the material being processed. As the material enters the barrel, the screws transport it along the length of the barrel while subjecting it to mechanical forces, shear, and heating.

The intermeshing screws have a specific profile or flight design, with different elements such as kneading blocks, conveying elements, and mixing zones. These elements are strategically positioned along the screw's length to perform specific functions. The design of the screw elements can vary depending on the desired processing requirements and the characteristics of the material being processed.

As the material moves through the twin screw barrel, it undergoes several processes. The screws convey the material forward, while the intermeshing action creates shear forces, promoting mixing and dispersion of additives. The material is also subjected to heat through external heating elements or barrel heating zones, which helps in melting or softening the material for further processing.

The combination of shear, mixing, and heat within the twin screw barrel allows for efficient and uniform processing of the material. This is particularly useful for tasks such as compounding, blending different materials, devolatilization, reactive processing, and achieving specific product properties.

Overall, the twin screw barrel in an extruder enables precise control over material processing, enhancing product quality, productivity, and versatility in a wide range of applications.

Extruder conical twin screw barrel
Extruder conical twin screw barrel
45/90, 45/100, 50/105, 51/105, 55/110, 55/120, 58/124, 60/125, 65/120, 65/132, 65/138, 70/135, 70/140, 75/150, 80/143, 80/156, 92/188, 105/216, 110/220