Leverkusen, Germany -- 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 in part 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.
It is vital that the coating is applied precisely to the upper material at the points where the foot needs support. There, the coated material, with high resilience, braces the foot but also offers it enough freedom to stretch, contributing to a "natural running experience," says BMS.
In designing the coating, adidas experts drew on the results of measurements from sensors placed on runners' bare feet.
Use of the coating provided the designers with free design scope. Also, the process protects the synthetic upper because the shoe is not subjected to thermal stress during production.
"We developed the concept for the textile coating in close collaboration with adidas and then perfected it in laboratory trials," says Thomas Michaelis, a specialist for textile coatings at Bayer MaterialScience.
While such trainers may be helping Olympic athletes this summer, another Impranil use is also being exploited at the London Olympic Park. Screen-printed coatings offer highly elastic bands in the latest adidas sportswear with Techfit PowerWeb technology. When these bands are stretched in competition, the material briefly stores the energy of an athlete's movement, and converts it into increased speed and power.
This improves performance and prevents premature fatigue, says BMS. The compression also avoids muscle vibration that can cut performance.
Impranil dispersions are waterborne and co-solvent-free. According to BMS, textile coatings formulated with Impranil retain their excellent properties after machine washing and drying. Stress-strain tests provide impressive proof of their high resilience.