Bavaria, Germany – Skateboarders are the latest sports fans to benefit from BASF’s innovative thermoplastic polyurethane (TPU) Infinergy, with a new shoe from adidas.
Inspired by the lightness, elasticity and rebound of a tennis ball, according to BASF research chemist Frank Prissok, Infinergy technology has been used in the adidas range of Boost running shoes since 2013.
The innovation pivots on the cushioning properties that stem from a solid granular TPU made into thousands of small energy capsules, or TPU pebbles, inside the shoe’s midsole.
Tests conducted by adidas show the material “provides the highest energy return in the running industry” the firm said.
Prissok added: “Infinergy is the first expanded thermoplastic polyurethane (E-TPU). It is a closed-cell elastic particle foam consisting of individual beads.
“The individual particles of 5-10-mm in size are pressed and fused against one another in the manufacturing of parts. It is particularly lightweight - bulk density - 100g/l - very elastic, tensile and stretchy.
“The foam has high long-term durability and outstanding resilience – better than EVA (ethylene vinyl acetate), which has previously been used in the majority of sports shoe midsoles,” he added.
The technology was developed using BASF’s Elastollan, as previously reported at utech-polyurethane.com.