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In the fight to recycle used clothes and accessories, footwear has long been a drag in the process. Of the 20 billion shoes produced each year, a huge 95 percent end up in a landfill. But now a recently developed recycling process looks set to revolutionize the world of footwear recycling. This system is separate the leather from the rubber and transform it all into minuscule granules, meaning that your old stinky sneakers could become part of a brand new rubber playground!
The process of segregating rubber, plastic, leather and metal is no mean feat: just one shoe can contain 40 different types of materials, not to mention the glue that so often holds them together. But the complex mixtures of material in the shoes didn’t dissuade the folks Loughborough University’s Innovative Manufacturing and Construction Research Centre (IMCRC), however. They have been working on research for the process for ten years, with funding from the Engineering and Physical Sciences Research Council (EPSRC).
Professor Shahin Rahimifard led the project. He says that in this process the first step is to manually pre-sort shoes into broad types, such as trainers, and to recover metals, such as eyelets. Following this “the shoes are automatically shredded and granulated, with the granules automatically separated into four waste streams: leather, foams, rubber and other material.”
Once these are separated the shoes become 3-4mm fragments using a granulator. These, in turn, are separated depending on their different sizes and weights.
Its amazing to think what practical purposes our old footwear could have in their new lives beyond our feet. For example, recovered leather fibres could be reformed to produce bonded leather sheets; reclaimed rubber as a running track; and recycled foams can be used in underlay material for carpets. This recycling breakthrough could indeed lead to some huge environmental benefits.