The Herzogenaurach sportswear manufacturer Puma has shown that a specially made version of the Suede sneaker model can be biodegraded in an industrial composting plant. The company released the results of its two-year Re:Suede experiment in a detailed report on Wednesday.
In 2021, the sportswear retailer produced 500 pairs of the Re:Suede test sneakers. The classic model was made from Zeology-dyed suede, biodegradable TPE (thermoplastic elastomers, i.e. plastics) and hemp fibers. In contrast to conventional tanning agents, Zeology is chrome-free, heavy metal-free and aldehyde-free. In March 2022, the company was looking 500 volunteers for the Re:Suede product test. The sneakers were worn by the participants for six months to test their comfort and durability. 412 test models were then sent to the Dutch composting expert Ortessa to check whether the sneakers can be biodegraded.
Sneakers become compost
The industrial composting process took place in a tunnel measuring around 150 square meters. To do this, the shoes were first shredded and mixed with other organic waste. In the composting tunnel, the waste was enriched with bacteria and biodegraded. To ensure optimal conditions, the temperature, humidity and oxygen content were controlled. The contents of the tunnel were sifted at regular intervals of around two weeks to check how small the remains of the composted shoes were. After around three and a half months, the first mined materials were sold as grade A compost for agricultural use in the Netherlands. The remaining materials that had not yet reached the desired level of shredding were returned to the composting tunnel. The soles of the sneaker are the hardest to break down and, according to Ortessa’s estimates, require several composting cycles to fully break down.
“We will continue to innovate with our partners to develop the necessary infrastructure and technologies necessary to make the process viable for a commercial version of the Re:Suede, including a take-back system, in 2024,” says Anne-Laure Descours, Chief Sourcing Officer at Puma.
Based on the previous product tests, Puma also wants to improve the wearing comfort of the shoe in the future by adapting the upper material and revising the material of the sole.
The Re:Suede experiment is part of Puma’s innovation platform Circular Lab, which works on various projects to improve the company’s circular economy.