Cost efficient recycling of elastomeric materials with noise and vibration damping applications; CERMAT
At first, final recycled composites specifications have been determined for all identified target applications. A reference database on vibration damping properties of PUR and rubber was established. Elastomeric composites modelling software was developed. Extensive physico-chemical tests have been performed on powders and granulates. Moreover, many innovative powders activations methods have been developed (hygro-thermal decomposition, chemical swelling, peroxidation, photo-chemical grafting, Corona). Efficiency of those methods have been assessed, especially regarding the improvement of the mechanical quality of the produced recycled composites. Data on available recyclable wastes sources have been gathered. An extensive work has been done in order to perform the life cycle assessment analysis on the six proprietary recycling routes that have been identified at an end-users meeting. Environmental impacts of each of those recycling processes have been quantified and assessed through combination of data obtained from both the partners and other industrial or official sources. Tyre rubber and PUR foams powders have been produced with various crushing techniques. Full characterization of powders physico-chemical properties has been performed and comparative analysis have been made in order to determine the best crushing methods. Optimization of SCANRUB's crushing line was performed (GENAN plant), especially with the implementation of a cryogenic section. Development and implementation of innovative separation techniques have been done (steel separation process, particles image analysis for impurities detection, ozone knife technology for rubber/textile separation). Various innovative recycling processes have been developed for each of the 5 types of composites covered by the work-programme. Many batches of recycled elastomeric composites have been produced with different processing technologies: their physico-chemical and mechanical properties have been measured: good exploitation potential has been identified in a wide range of products. Some of the produced materials involve up to 96% of recycled elastomers. Analysis of the results led to a continuous re-definition of work guidelines for the project regarding sound and vibration damping and physico-chemical characteristics of the produced composites. In total, about 60 different sets of materials and composites were fully evaluated by the partners. Pre-normative studies have been performed in the domain of elastomeric powders characterization (impurities level, shape, surface analysis, swelling) and on quality specifications for products based on recycled elastomers. A synthesis report including drafts of standard procedures has been issued. Prototype production task was performed during the last year of the project. Technical elastomeric parts (solid wheels, trawl bobbins, road cones, pavement tiles), packaging materials, shoe soles, vibration damping plates and coatings, cylindrical dampers, rubber/concrete elements have been produced and tested. Very good results were obtained for processing, cost and quality aspects. Scaling-up of the production processes was also analysed. A wide set of demonstrators with marketing opportunities is available for exploitation.