Techniques for separation of plastic wastes

Global plastic production is continuously increasing and there is a strong need to increase plastic recycling accordingly. The most demanded polymers and their main applications are introduced and an overview of the different operations forming the plastic recycling chain is presented. Mechanical recycling is the most important option to recover plastics; it can be carried out at “macro” or “micro” level, depending on the size of plastic waste. Separation technologies are divided into gravity separation, electrostatic separation, magnetic density separation, flotation, and sensor-based sorting. Auxiliary technologies usually found in plastic recycling plants are also described: magnetic and Eddy current separators. The importance of recycled plastic quality control and product certification is strongly pointed out, reporting both traditional and advanced quality measurement techniques. The final section is devoted to list some of the main current research topics on plastic recycling.