Most shoe racks in our homes are filled with shoes partly, or in many cases fabricated from plastics and plastic-like materials, from the squishy soles to the pointy heels to the knit polyester uppers to the brittle eyelet holes. Because of their construction- usually, the components are stitched and glued and moulded together in complicated ways-they are almost impossible to recycle. So sadly, your feet are only a stopover in their long, long lifetimes, before they pile up in landfills and float down waterways, often living on like zombies for hundreds of years.
The first stirrings of a shoe revolution are fomenting, though, and the industry is starting to look hard at ways to build a better or more sustainable mousetrap for our feet. To understand the contribution of our feet to a squishy mess of plastics we have to understand how it all started.
In the 19th century, shoes were made from materials found in the natural world. Wood for heels, tanned leathers for uppers and straps. Soles were rubber or cork, or at times chunks of wood carved to cradle afoot. But a shifting culture and materials science was coming for shoes, as they came for everything else. So with time, plastics took over the shoe industry making a tenfold pair which ends up as waste from the short life span a shoe made out of plastics harbors.
The results were tragic. We now talk about greenhouse gas emissions and the plastic menace.
Planet or plastic
The solution to the feet menace, rubber. A new chemical process that kept rubber stable at warm temperatures- vulcanization- was invented in the 1800s. that stable rubber quickly made its way into tires, like seals on steam engines- and onto the soles of shoes. This original rubber that went through the process of vulcanization wasn’t what we now think of like plastic. But in the middle of the 20th century, natural rubber was replaced by synthetic rubbers- a close relative of the plastic materials. Today, about 70% of all rubber used in manufacturing is synthetic.
Well, fashion drives innovation. It’s a product of desire and design. Plastic and plastic-like substances have completely reshaped the footwear landscape. They have made shoes better, lighter, faster, more comfortable and more accessible worldwide.
Can shoes be made in a way that uses less planet choking plastic?
Some shoe companies are looking to the past to excise plastic. The trends in athletic footwear design lately, is less plastic. Think Nike Flyknits, with their stretchy knit uppers. It is partly inspired by aesthetics, but also by economics because it is cheaper to make a shoe that requires fewer pieces to glue or sew together.
That design also offers an interesting opportunity. A shoe that uses a variety of materials is tricky, if not impossible to recycle. So a shoe that uses only one material offers at least some hope of being recycled eventually. Adidas is working on making a shoe that fits these principles. Their “futurecraft loop” sneaker, in development now, is made of one single material- thermoplastic polyurethane) that can be at least partly recycled. Other brands are making shoes out of recycled ocean plastics.
But the limits of plastic recycling are currently hard. It takes energy to collect the materials, remake them into their second existence- and in many cases, that second life is their last, so recycling extends the process but does not solve the underlying problem.
The future looks stranger, from climate change to plastics everywhere. The creative solutions will be necessary if we are going to kick our plastic habit.