Composition and Workability of Plastic Fractions Recovered from Commingled Waste Discarded by a Composting Plant

This paper deals with the recovery of plastic fractions from waste discarded by an industrial composting plant that processes the organic fraction of municipal solid waste. Polymeric fractions (PE, PP and PET) were sorted from this discarded waste using a NIR separator. The polymeric fractions were then washed to remove residual contaminants and characterized with the aim of assessing their composition. A process of pelletizing and injection molding suitable for producing specimens made of 100% of these recovered materials was set up. The tensile strength and stiffness, as well as the microstructure of the recycled plastics, were investigated. The mechanical features of samples fully made of recycled PE and PP were like those characteristic of virgin polymers. Samples made of PET did not show completely satisfactory properties, as they displayed rather poor elastic modulus and ductility.