Sorting of plastic waste for effective recycling

Separation of plastic from various types of waste streams represents one of major problematic process in energy recovery through different thermochemical processes. The sorting of plastics is a very essential step in different waste management technique. Manual sorting is suitable when plastic component are present in large amount but it is a labor intensive process. In automated sorting technique NIR(near infrared) offers great advantage among all wave sorting technique but not suited for dark coloured plastic and can be used on transparent bodies. In air sorting lighter particles are separated from heavier ones based on specific gravity. In electrostatic sorting method materials are separated based on electrostatic charge. In float-sink separation technique the plastics are in a fluid that has density in between the materials making it possible for less dense material to float and heavier to sink whereas sorting by selective dissolution is based on batch dissolution of mixed plastics using solvents. Hydrocyclones enhance the difference of specific weight by centrifugal force so materials with little difference can be separated as well. The present paper reviews the available literatures in the area of sorting of plastic waste for effective recycling.