Plastic recycling equipment can recycle many different types of plastics such as PET, HDPE, PVC, polyethylene, polypropylene, etc. depending on it uses or end result needed. Plastic globally processes and resells millions of tons of used plastic materials every year. Although plastic is generally used for scraps and byproducts it now can also be used to reclaim heterogeneous post-consumer goods and materials. Each plastic recycling process is different depending on the type of plastic be processed. There are general practices that are essential when using plastic recycling equipment. These are the stages of sorting, size reduction, cleaning, separation and pelletizing and all in the order.
The sorting machines need to quickly determine and classify huge quantities of post-consumer plastic, under constant feedback. An advanced sorting machine can be equipped with sensors, ejectors, computer systems and user interfaces for maximum efficiency.
Size reduction can consist of shredders or plastic granulators with different size screens that produce the desired size of the needed application of the plastic. The shredder has a scissor cutting effect. The granulator depends on the shape and speed of the rotor. It has more precise control over the size of cuts compared to a shredder. The general term of the output plastics in this step is called flakes.
The cleaning and washing stage removes residual dirt and residue, such as glue, paper, grit and sand. They can go through a bath, friction washer or washing line. It applies a continuous hot spray along with detergents and disinfecting products for cleansing.
The separating equipment reduces the possibility of stock contamination and removes any non-reusable materials. The two types of processes are called dry or wet methods. The wet method use a float tank that separates the plastic materials based on density. The dry method is separated by air types such as thicker pieces sifting away from thinner ones.
Pelletizing is the final step in the plastic recycling process. The pelletizing machine generally uses a single or double screw extruder with different ratios depending on the desired result. The single screw extruder uses a pumping action while the double screw uses a mixing function to create the shape of the plastic for final use.