International, USA

The race to make new athletic shoes from old ones

Athletic shoes don’t last that long and most are made from a wide variety of materials, some of which can take 1000 years to break down. Decades ago, Nike started turning old shoes into Nike Grind which could be used as athletic surfaces. Now designers are taking different approaches to creating a circular economy, where old shoes can be turned into new.

Step 1: Simplify materials

Thousand Fell, based in the US, focused on how to design a shoe that could be disassembled without contaminating the materials and then choosing materials that could be recycled. 

They settled on a shoe made from rubber, bioplastics derived from coconut husks and sugar cane, polyester and other plastics including ether foam. The polyester and rubber components are recycled back into materials that can be used again in shoes; the ether foams are open-loop recycled, meaning they can be used in other products. Finally, the bioplastics are sent to an industrial compost.

French-based Solomon focused on using fewer materials. The sole can be used in ski boots but they’re just storing the uppers until they can find a solution.

In May 2021, they released a sneaker called the Index.01 made of two main materials, a polyester upper and a thermoplastic polyurethane (TPU) sole. When the shoes are returned to Salomon, they are split using scissors. 

The Swiss company, On, has made the Cloudneo, made from only one material.

According to Heitz, the beauty of the material is that it is thermoplastic, which means it can be recycled over and over again. The plastic is versatile enough to be turned into most of the shoe’s components, from laces to soles. It has only been on the market since June 2022, so there aren’t enough old shoes available to replace virgin inputs, but Heitz is confident this will change over time.

Step 2: Get old shoes back

Designing a recyclable shoe is probably an easier task than developing a system to get the shoes back. Again, manufacturers are trying different business models: credits and subscriptions. 

Thousand Fell and Salomon rely on customers taking the initiative and sending shoes back to them (Thousand Fell offers a $20 credit for every old pair returned). But On have built return into their business model by only offering the Cloudneo shoe on a subscription basis. For US$29.99 or £25 a month, subscribers are sent as many shoes as they wear out, so long as every old pair is posted back to On.