Innovating midsoles for athletic sport shoes performance with TPEs
PERFORMANCE or sustainability? For years, that’s been the choice facing athletic shoe designers, leaving the global footwear market at a crossroads. Long-time favourites, EVA midsoles, tick the boxes for cost and processability but fall short on rebound and recyclability.
Athletes demand higher performance, while consumers increasingly expect sustainable products. For brands and OEMs, the challenge is clear: create midsoles that balance performance, comfort, sustainability, and cost-efficiency.
According to Envalior, the solution lies in Arnitel® TPE (thermoplastic polyester elastomer), a next-generation midsole material designed to deliver both high performance and environmental benefits.
Rethinking materials
As the industry shifts toward cleaner options, traditional materials like EVA are being reconsidered. Emphasis is growing on recyclable, bio-based, and low-VOC materials that align with both performance and sustainability goals.
Leading footwear brands are now experimenting with advanced thermoplastics and physical foaming technologies to produce midsoles that meet these dual demands. Finding a material that balances performance, durability, and environmental impact, however, remains a challenge – many current options come with compromises.
What Arnitel® brings to the track
Envalior’s Arnitel® is a high-performance thermoplastic polyester elastomer already used by leading athletic footwear brands. Unlike traditional EVA, it is processable via physical foaming, enabling midsoles that enhance both speed and endurance. Its benefits include:
1. High energy return
• Enhances athletic performance with superior energy return
• Reduced hysteresis enables higher dynamic rebound and greater resistance to compression
• Optimised force distribution from heel strike to toe-off
2. Longer lasting
• Exceptional longevity across various terrains, reducing the need for frequent replacements
• Low energy dissipation under stress, unlike TPU, which typically generates heat
• Minimal frequency dependency ensures consistent dynamic resiliency at high strain rates
3. Consistent performance
• Reliable across climates, from -20°C to +100°C.
• Maintains energy rebound and modulus in diverse trail and weather conditions
4. Sustainable
• Long lifespan reduces carbon footprint over the shoe’s life
• Portfolio options with reduced carbon impact, and fully recyclable within PET streams
The next step
As sustainability moves from a “nice-to-have” to a nonnegotiable, materials suppliers must deliver real solutions. Arnitel® TPE shows that recyclability and high performance can go hand in hand, pointing the way toward a more circular, lower-carbon future for athletic footwear. This has already been proven in practice: the norda™ 005 ultra-distance trail shoe, unveiled at the UTMB race in Chamonix on August 27, 2024, uses Arnitel® midsoles and is shown to combine high rebound, durability, and low weight with a sustainable, recyclable design.
