Manufacturing process optimization of resilient materials made from recycled tyre granules

Recycled tyre granules have been recently proposed for manufacturing acoustic insulating and absorbing materials, to be used for noise control in buildings and road barriers. The pro-duction of these materials can therefore be a valid alternative to the disposal into landifill or incineration of end of life tyres. Previous studies made by the Authors and others have proven that materials made of recycled tyre granules mixed with binders can be conveniently used as insulating underlays with good impact sound reduction performance. The paper presents the first results of the collaboration between the Department of Industrial Engineering of the University of Perugia and the European Center of Nanostructured Poly-mers. The goal of this multidisciplinary partnership is to analyze and optimize the manufac-turing process of these materials by studying the different stages of production. Several prototypes have been manufactured by means of the developed process and tested in order to evaluate their dynamic stiffness in compliance with the European standard EN 29052-1:1993. The indexes of impact sound reduction Lw were also estimated. Finally the prototypes showing the best properties have been produced in bigger size and tested in two overlapping reverberating rooms according to the standard ISO 140-8. The re-sults confirm that the materials manufactured through the developed process have satisfac-tory acoustic properties, comparable to the ones of commercially available materials.