granulators

A granulator is a size-reduction machine designed to convert materials into small, uniform granules. In plastics processing and recycling, granulators turn scrap parts, runners, and regrind into feedstock that can be re-melted or pelletized. The term is also used for equipment that granulates other materials, such as wood residues and certain agricultural products, depending on configuration and tooling.

Most plastic granulators use a rotating knife set that cooperates with stationary knives to shear material against a perforated screen. The feed enters through a hopper, is cut by the blades, and exits via the screen, creating granules whose size is controlled by the screen aperture. Machines are typically designed as single-rotor or twin-rotor units and may be belt- or gear-driven. Optional features include dust collection, cooling, and automatic knife adjustment.

Common inputs include post-consumer and post-industrial plastics, such as PE, PP, PET, ABS, and PC, as well as some wood fibers and other resilient materials in specialized models. The output granule size ranges from a few millimeters up to several centimeters, depending on the screen and process set points. Granulators are often paired with conveyors and downstream pelletizers or extruders.

Key considerations for use include blade wear, heat generation, and energy efficiency. Proper pre-processing, screen selection, and routine maintenance are essential to product quality and equipment life. Granulation supports closed-loop recycling and material cost savings by enabling scrap to be reprocessed rather than discarded.