Chapter 1 — full chapter
1.3.2 Case Example — Salomon INDEX: Designing a Product around Its Next Material Life
The Salomon INDEX project began not with a conventional running shoe, but with the question of what its materials could become after use. Because footwear typically combines numerous foams, rubbers, textiles and adhesives that are difficult to separate, the INDEX.01 was developed around two principal material groups: a polyester upper and a thermoplastic polyurethane (TPU) bottom unit.
The choice of materials and the intended recycling pathway influenced the shoe’s construction, colour, component architecture, and return system. After use, registered products could be returned to Salomon, separated and processed. In Europe, recovered TPU was used in the production of alpine ski boots, while polyester was directed towards new textile applications. The next life was therefore considered before the first product was designed.
More importantly, INDEX became a broader design platform rather than a single experimental product. Subsequent running-shoe iterations refined material efficiency and performance, while the same design logic informed the Brigade INDEX helmet, developed using 96% materials from one plastics family so that it could be recycled without disassembly.
Approximately 85% of the shoe by weight—the TPU bottom unit—was designed to be recycled into ski-boot components. The remaining polyester upper was intended for textile recycling, although implementation of this pathway proved more challenging.
The project demonstrates that designing for multiple life cycles does not have to mean adding modular panels or replaceable trims. Innovation can redefine material combinations, manufacturing methods, aesthetics, reverse logistics, and even the relationship between product categories. In this case, the future material pathway became part of the design brief.
Figure 12. Salomon INDEX demonstrates a material-led approach to multiple life cycles. The intended transformation of a running shoe into feedstock for ski boots and textile applications influenced the product’s materials, construction and return system from the outset. Source: Authors’ own elaboration based on Salomon, Introducing the INDEX.01 Recyclable Running Shoe, Recycling the INDEX.01 and Salomon Unveils the Brigade INDEX Helmet.