The side feeder, or lateral feeder, is an essential component in co-rotating extruders. It plays a fundamental role in introducing various types of fillers into the main extruder, including diverse materials such as glass fibers or calcium carbonate, depending on the specific needs of the extrusion process.

This component consists of a twin-barrel, a cylindrical casing with two openings, and a pair of screws. These screws generally have a relatively short length-to-diameter ratio (LD) and a simple geometry, suitable for their main function of feeding the extruder with the material.

Despite its seemingly simple structure, the side feeder plays a fundamental role in ensuring a steady and uniform flow of materials inside the extruder, thus contributing to maintaining the efficiency of the extrusion process and facilitating the creation of high-quality products.