Resources, Conservation and Recycling

The increasing scarcity of virgin material, the existing and forthcoming European producer responsibility directives and ever-increasing landfill charges necessitates that the appropriate end-of-life management and recycling of products are implemented in every manufacturing sector. In some product sectors, such as waste electrical and electronics and end-of-life vehicles, there has been a rapid growth in recycling activities driven largely by the economic values of materials. 

However, for consumer products, such as footwear, with limited valuable material content there are significant challenges for establishing an economically sustainable recovery and recycling process.

Until legislation arrives the establishment of a sustainable footwear recycling system is at present very much dependent upon the economical viability of the operation. To this end an automated recycling process, based upon low cost air separation technologies has been presented. The initial investigation and experimentation has focused on the separation of postconsumer shoe materials into four primary recycled material streams: rubber, leather, foam and textile fines. For each of these materials a number of potential applications exist, such as surfacing, insulation and underlay product. It must be noted that this can be defined as a down-cycling approach and may not provide the greatest environmental benefit, highlighting the requirement for further investigation into higher grade recycling scenarios to support long term recycling activities in this sector.

However, for high value applications, such as the manufacturing of new products, it is widely acknowledged that the reclaimed material stream should have purity in excess of 95%. Clearly it may not be possible to achieve this level of purity with the proposed system. Further work therefore needs to be done to investigate the technical feasibility as well as the economic and environmental impacts of alternative recycling approaches (e.g. sensor based sorting or electrostatic separation) for postconsumer footwear products. Improved material recovery can also be achieved through proactive approaches, such as better footwear design to support recycling, improved reverse logistics and collection and creation of novel recycled materials applications. In particular footwear design is seen as a key factor to enable significant improvements to material reclaim yield and purity. Thus the authors are currently working with producers to investigate the implementation of ‘design for recycling’ within the footwear sector. It is argued that such proactive apaches will give early adopters a significant competitive advantage when environmental legislation reaches the footwear sector.       

You can access thee full repor here:  An_air-based_automated_material_recycling_system_f (3).pdf