Twin screw extruder

Extrusion transforms viscous substances into high-quality structured products by accurately controlling processing conditions. Extruder can be used in plastics industry, food & Pet food industry, chemicals industry, pharmaceutical, minerals and nonwovens industry. Raw materials can be solids (powders, granulates, flours), liquids, slurries, and even gases. Once extruded, these materials become plastics compounds, chemically modified polymers, textured food and feed products, cellulose pulps, and other products.

Single-screw extruders utilize one screw and twin-screw extruders use two intermeshing screws. Both styles of extruders operate in a similar manner, providing transport, compression, mixing, cooking, shearing, heating, cooling, and shaping of raw material final products. In a twin screw or multi screw extruder there are two screws.

Twin screw food extruder is mainly designed for making puffed food. It is developed on the basis of the single screw extruder. Twin-screw extruders provide excellent mixing of material and forming and are widely used to process powder blends that need to be thoroughly mixed as well as being melted and formed.

A twin screw extruder is a machine consisting of two intermeshing, co-rotating screws mounted on splined shafts in a closed barrel. The screws are tight and self-wiping, which eliminates stagnant zones over the entire length of the process section.

In a co-rotating system, the screw transports material around up to the point where the screws intermesh. Because of the two opposing and equal velocity gradients acting at this point, material is taken over by the other screw with the least amount of material passing through the gap between the two screws.

The screws play the role of transport, friction, extrusion, and heating together. This system results in high efficiency and perfect self-cleaning with greater control over residence time distribution.

Twin-screw extruders are applicable in industries because of their high capacity. Extruders with twin-screw and short distance between screws have high capacity and good thermal and mechanical stress.

Due to its good feeding performance, mixing and plasticizing performance, exhaust performance, extrusion stability, etc., it has been widely used in extruded products. Compared to single screw extruders, twin screw extruders are more efficient in providing homogeneous mixing of different ingredients such as additives, fillers, and liquids.
Twin screw extruder