Plastic water bottles can be recycled into shoes. The process involves turning the ground-up bottles into recycled filament fibre.
Rothy's is a San Francisco-based startup company which uses a proprietary process to 3D-knit the fibres into seamless, essentially waste-free, shoes and the knitting process takes just six minutes to complete.
A similar approach has been used to make the Nike Flyknit line of trainers, but Nike's shoes are knit in two-dimensions, Rothy's are "knit to shape" in three dimensions and come out of the machine fully formed. Eventually, the process could be used to knit shoes on demand.
In total, the shoe only uses three materials. The upper and insole are made entirely from recycled water bottle filament and attached to a recyclable foam. The sole is made from rubber. The designers spent eight months trying to build a supply chain in the United States, but when it failed they went to China where the shoes are made. The company plan to plan add solar panels to the factory to improve sustainability performance even further.