Innovative recycling methods for elastomers
Elastomers are materials with a very wide range of application. Apart from their common use in our daily life as rubber bands or shoes they are also extensively used in other industrial sectors like the aerospace industry or the automobile industry. Such a widespread usage is due to the novel properties these materials display, namely their large elastic deformation and their excellent noise and vibration damping capabilities. These materials, therefore, can also improve the quality of transport means (cars, aircrafts, railway vehicles) by fast damping vibrations and upgrade working environments, providing effective noise insulation. However, this extensive usage also results in a large amount of scrap material, that is not immediately degradable. Cost Efficient Recycling of elastomeric MATerials (CERMAT) is a multinational European project that has developed complete recycling processes for rubber and polyurethane (PUR) waste, resulting in mass production of recycled low cost elastomeric composites with good noise and vibration damping capabilities. These recycled elastomers will re-enter the production chain at low costs and consequently aid industries in remaining competitive. Life cycle assessment analysis of six proprietary recycling routes has been performed and for each of those their environmental impact has also been assessed. The physico-chemical and mechanical properties of the recycled elastomeric composite materials produced have been extensively studied. Five types of different composites and sixty different end materials have been covered by the project, some of them containing up to 96% of recycled elastomers, while most of them have good exploitation potential. Tyre rubber and PUR foam have been developed in the form of powders using a number of different crushing techniques. Their properties like impurity levels, shape, surface analysis and swelling have been characterised in detail and a report on standard procedures for their synthesis has also been issued. With the produced recycled elastomeric composites a number of prototype production tasks were undertaken during the final stages of the project. Technical parts like road cones and pavement tiles; packaging materials; shoe soles and a number of other products were produced and tested. Scaling up the production process is feasible and already a set of demonstrators with marketing opportunities is available.
