Materials manufacturer Covestro and orthopedic service provider GeBioM mbH, based in Münster, Germany, are expanding their cooperation in the field of orthopedic footwear. In addition to producing lasts and trial shoes, they now support orthopedic shoemakers in the production of custom insoles using 3D printing. A new Addigy® FPU 79A thermoplastic polyurethane (TPU) from Covestro is used in the form of filaments. Together with Danish printer partner Create it REAL, the companies offer a novel and sustainable solution for the digital production of shoe insoles.
"Our new TPU plastic and a printer developed specifically for this application make it possible to print very soft structures. The material and printer were harmonized during development to achieve a perfect result," explains Lukas Breuers, 3D printing expert at Covestro. "With the help of the automated software solution, soft and hard structures can be combined in a shoe insole, achieving a level of customization that was previously virtually impossible." The TPU also meets the requirements for medical devices with regard to cytotoxicity and skin sensitization in accordance with the DIN EN ISO 10993-5 and 10993-10 standards.
In addition to functionality, the development of the material also focused on its ecological footprint, as Marcel Domenghino, Managing Director of GeBioM, points out: "It was important to us that the new solution also allows for improved sustainability. Currently, the production of insoles also generates large amounts of waste. Moreover, the insoles themselves are hazardous waste after use. With 3D printing, we now enable our customers to produce in a waste-free manner by using only the material that is needed for the insoles."
Aiming for recyclable material
Covestro is currently working on a recyclable TPU for this application and is developing opportunities with GeBioM and value chain partners to recover used insoles for recycling. Already, the spools on which the filament is wound are reused. The development is part of a global strategic program to fully align the company with the Circular Economy. Components of the program include innovative recycling technologies and the increased use of alternative raw materials such as biomass, CO2 and plastic waste, as well as renewable energy.
Covestro has been committed to developing innovative material solutions for additive manufacturing products for years and offers a versatile product range under the Addigy® brand, including for orthopedic shoe insoles. Just recently, the company also significantly strengthened its 3D-printing portfolio with the acquisition of the Resins & Functional Materials business of the Dutch DSM Group.