A plastic granulator is used to shred unwanted or rejected plastic materials into small, uniformly-sized pieces that can then be reused in a variety of ways. Typically, a plastic granulator is comprised of an electric motor that turns a rotor, which then cuts the material into granules. The granulator is also equipped with a screen that forces the granules into groups based on their size and shape. This process reduces the amount of waste that is created during production.
There are a few different kinds of plastic granulators available, depending on the application. “Beside-the-press” granulators are generally used to grind relatively low volumes of sprues, runners, and off-spec parts from injection or blow molding processes so that they can be immediately recycled back into those same processes. Central granulators are designed for high-volume crushing of all kinds of plastic wastes or rejects from injection, blow, and extrusion lines.
The main difference between a plastic granulator and a shredder is that granulators are built to cut/slice materials, whereas shredders are optimized for shearing (tearing). Shearing relies on the sharpness of cutting edges working against each other. In contrast, tearing reduces materials by applying torsional force that causes them to come apart. This is why purpose-built tearing reducers are better for reducing mixed waste than shearing devices, which are more effective at reducing plastics.
This open source waste plastic granulator was built using readily-available components and materials costing less than $2000 USD. The resulting machine draws very little power and uses only about 3-4 conventional incandescent light bulbs worth of embodied energy during operation. It also generates very little noise and is consistent with the granulation requirements of post-consumer waste and 3D printer polymer feedstocks for distributed recycling and manufacturing using recyclebots and 3D printing machines.
The daily operation of a plastic granulator begins by feeding pre-shredded plastic into the machine. As the rotors rotate, the shredded plastic is forced through a screen that separates them by size. The resulting granules are then ready to be used in the manufacturing process. A good plastic granulator should be sturdy and safe to use, working well with a wide range of products including cables, drums, and E-waste. Talk to a Waste Initiatives representative today to see if a plastic granulator would be right for your company. We have a large selection of granulators, with capacities ranging from 1T/hr to 2T/hr. Our smallest model is a great choice for smaller applications and facilities with limited space. We also have mid sized and larger models that work well for large facilities. We can help you determine which type of granulator is right for your company and then design it to meet your specific needs. We have experience in designing and installing custom hoppers and infeed systems, as well as dust collection and blower cyclone extraction system options. Our experts can also help with a variety of additional process and facility optimizations to improve your overall efficiencies.