The new “adipure” line of training shoes from adidas supports natural running through a rolling motion over the metatarsus and forefoot. The shoes also satisfy runners’ other requirements, thanks not least to the upper material of the shoe, which envelops the foot seamlessly like a second skin. It owes its unique properties to a textile coating based on a polyurethane dispersion from Bayer MaterialScience’s Impranil range.
The textile coating is noted in particular for its high resilience. It is vital for the runner that it is applied precisely to the upper material at the points where the foot needs support. There, the coated material braces the foot but also offers it enough freedom to stretch. As a result, it makes a decisive contribution to the runner’s perfect natural running experience. Athletes train in adipure shoes to improve and refine their running style.
When it came to designing the coating, the adidas experts drew on the results of measurements obtained with the help of sensors placed on runners’ bare feet. The application of the coating provided the designers with almost unlimited design scope. Furthermore, the process protects the synthetic upper because the shoe is not subjected to any thermal stress during production. "We developed the concept for the textile coating in close collaboration with adidas and then perfected it in laboratory trials," said Thomas Michaelis, a specialist for textile coatings at Bayer MaterialScience. Bayer and adidas have been collaborating for over 25 years, for example in the development of the official soccer balls for the European Championships and the World Cup.
Jerseys boost muscle performance
Screen-printed coatings based on Impranil are also used as highly elastic bands in the latest adidas jerseys with Techfit PowerWeb technology. When the bands are stretched in competition, the material briefly stores the energy of an athlete’s movement, which would normally be lost, and converts it into increased speed and power. This improves performance and prevents premature fatigue. The higher compression avoids undesirable muscle vibration that can affect an athlete’s performance. Furthermore, the actual coating technology produces significantly less waste than conventional production.
Impranil dispersions are waterborne and completely cosolvent-free. Textile coatings formulated with them retain their properties after machine washing and drying. Stress-strain tests provide impressive proof of their high resilience.