3D printing 100% recyclable soles with TPU from Huntsman

OESH Shoes (OESH), the U.S. footwear brand, has been evaluating how Huntsman’s thermoplastic polyurethane (TPU) materials can be used to create a 100% recyclable shoe sole via 3D printing – with positive results.

Founded by Casey Kerrigan, a Harvard M.D., OESH Shoes has been providing women with innovative, healthy footwear since 2011. As an internationally known researcher, who studied the effects of footwear on health, Kerrigan discovered that many common features of shoes can adversely affect posture and joints. She subsequently created OESH Shoes to translate her research findings into the design of healthy shoes.

OESH uses Huntsman’s TPU to produce soles using its 3D printing technique.

When OESH contacted Huntsman, seeking advice about the ideal material to use for 3D printing soles, Huntsman’s footwear team recommended TPU materials that had the specific comfort and performance properties OESH desired. Kerrigan and Huntsman worked together to evaluate the material and determine whether it could be shredded at the end of the shoe’s life cycle and recycled for re-use.

OESH put Huntsman’s TPU to the test – producing a series of soles using OESH’s unique 3D printing technique, which creates parts directly from pellets. The soles were then recycled into pellets and put back into the 3D manufacturing process. The next step was to test the new recycled sole against those made from virgin materials. Results showed that the recycled sole had the same functionality as the original sole with no drop-in performance properties.

Casey Kerrigan said, “At OESH Shoes, we are committed to making shoes that are not only the healthiest shoes on the planet, but also the healthiest shoes for the planet. We are constantly innovating and developing new technologies and manufacturing processes that minimize carbon emissions, toxins and waste.”

Jason Smith, Global Innovation Project Manager at Huntsman, said, “As a business, we are committed to helping our customers meet their sustainability ambitions – whether that’s delivering products that require less energy to process or supplying materials that can be recycled back into new items at the end of their life.”