It’s no secret that we at TechRunner are big fans of the Adidas Boost shoe– its revolutionary design and construction promises something truly unique that should benefit every kind of runner.
We’ve also previously covered how Adidas has partnered with tyre manufacturer Continental to provide the most responsive and springiest rubber for its shoes – now it’s time to take a look at BASF, the company behind the Boost’s exceptional foam system.
Named Infinergy, the foam consists of expanded thermoplastic polyurethane, or E-TPU. In an interview with Azom.com, Dr. Uwe Keppeler, material and process developer at BASF, explained how Infinergy is manufactured by foaming the starting material, TPU granules. “After pretreatment with pressure and heat, the individual granules measuring up to five millimetres each are blown up like popcorn”, explained Dr. Keppeler.
What happens next is the production of oval foam beads that have tiny gas bubbles inside. “These sealed air cells make the lightweight foam beads very elastic and provide the desired rebound effect. The individual beads can be imagined as being like tiny footballs: The more air they contain, the better they bounce and rebound back,” says BASF research scientist Dr. Frank Prissok.
Each Midsole contains approximately 2,500 of these foam beads, which are then converted by being treated with hot steam; this melts the outer-layer of the beads, which allows them to bond into a stable form.
What this means for the runner is that Infinergy midsoles essentially become energy stores for them; extreme compression combined with absorbing the shock impact of the foot combined with the lightning rebound elasticity enabling a large amount of energy to be returned to the runner.
“When the foot is pushed off the ground, the force expended is largely returned to the athlete. This results in completely new and improved running behaviour. Many runners have told us that the shoe feels like it is almost alive,” explains Gerd Manz, Senior Innovation Director Global Brands at Adidas.
This technology could also go into other types of industries. Infinergy could be used for producing unpuncturable tires or even types of flooring or running tracks. The possibilities of this technology could be endless with running shoes only scratching the surface.
[Additional information from Azom.com]