Salomon, the global leader in trail running and winter sports equipment, today unveiled its concept for a new performance road running shoe that can be fully recycled into a ski boot. The result of more than a year and a half of research and development, the recyclable concept shoe can be ground down at the end of its life, allowing Salomon to take the pieces, combine them with new material and use them to construct an alpine ski boot shell. Salomon is working to implement elements of this concept in running footwear that will be available in 2021.

“We recognize that we have to do better for the environment by creating Salomon footwear that drastically reduces its impact on the planet,” says Guillaume Meyzenq, VP of Salomon Footwear. “By creating this concept shoe that can be recycled into a ski boot shell, we are showing that it is possible to find alternative materials to create performance footwear. It’s an exciting development that will help lead us to more sustainable footwear solutions in the future.”

Roughly 30% of the global environmental impact caused by the footwear industry is due to the raw materials used in the products. To improve the carbon footprint of Salomon footwear, the company has been researching how to expand the lifespan of the material.

The concept
The key ingredient in the recipe of the recyclable Salomon concept shoe is thermoplastic polyurethane (TPU). Instead of using multiple materials to create the shoe, as is the case in the construction of traditional athletic performance footwear, the concept shoe uses only TPU to construct both the upper and the bottom units. This innovative construction enables the grinding and the re-use of the raw material without downgrading the performance.

The process
When the running shoe reaches the end of its life, Salomon is able to clean it and grind it into tiny pieces. These tiny pieces of TPU are then mixed with a bit of original (new) TPU and inserted into an injection machine to become a ski boot shell. The final ski boot shell has all the same performance characteristics as traditionally produced ski boots in the current Salomon range, which already use recycled plastics.

Why is this better for the environment?
Most traditional footwear construction relies on multiple materials such as cotton, polyester, EVA (Ethyl Vinyl Acetate) and rubber. Using multiple materials requires glue and stitching to bind those materials together. That makes most footwear nearly impossible to fully recycle because the materials must be separated from each other and the glue somehow extracted. Additionally, less energy consumption and no materials are wasted in the creation process of the Salomon concept shoe. Everything is utilized in the shoe.

And the running performance?
To ensure that the upper of this concept shoe is breathable enough to run in, Salomon engineers relied on two kinds of thermoplastic polyurethane (TPU). One has an extremely lightweight, almost transparent appearance to it. The bottom unit offers cushioning that
performs better than the EVA foam currently being used in most running footwear.

A never-ending commitment
“As a leader in running and the largest ski boot manufacturer, this is a unique Salomon solution to footwear sustainability that extends the life-cycle of the materials used by up to 10 times and drastically reduces the effect on the environment,” Meyzenq added. “Our work is always evolving in this area and it will be a never-ending journey, but this is an exciting step forward that will help us find solutions in the future.”

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