TPU outsole solutions: A compelling alternative to rubber for sports footwear
The outsole is ready for a rethink
Sports shoes are no longer worn for sport alone. Consumers move through training, commuting, and daily life in a single pair, expecting grip, durability, comfort and lightweight across every surface and setting. And as sustainability becomes a real purchase driver, footwear buyers increasingly look for designs with recyclability in mind.
For decades, rubber has been used for outsoles. Today, the industry is looking for materials that bring greater design flexibility, more efficient manufacturing and better recyclability, while still delivering the performance an outsole demands.
Outsole performance, made for efficient production
TPU brings together the elasticity, toughness and wear resistance required for high-performance outsoles. It can deliver rubber-like grip and durability, while opening a more efficient route to production. As a thermoplastic, TPU can be injection molded, helping manufacturers shorten cycle times, avoiding additional mounting steps and achieve consistent component quality compared with conventional rubber processing.
It also expands design freedom. TPU enables thinner and lighter outsole structures, with designs as thin as one millimeter, and supports transparent, translucent and highly varied color designs. As a recyclable material, TPU can help reduce production waste and support more circular footwear concepts from the start.
Footwear brands need outsole solutions that perform in use and support more sustainable production. With our third-generation XSG series, we help customers to provide an alternative to rubber without trading away performance, adding quieter comfort and building TPU-based sole systems with greater circularity potential.
The third generation: eXtra Silent and Grip (XSG)
Over the years, our TPU for outsoles has evolved across three generations, each building on the last. The earlier generations established the foundation: plasticizer-free grades with dependable grip and strong abrasion resistance that holds at temperatures above 100° to withstand the hotspots stressing the material through movements, especially jerkily ones during sport.
The third generation, the XSG series, takes that foundation further. XSG stands for eXtra Silent and Grip and the name reflects what it delivers. On wet and dry surfaces alike, XSG provides enhanced traction and can outperform previous grades and conventional TPU alternatives. This gives wearers reliable footing across running, basketball, tennis, and badminton, indoors and outdoors training.
XSG also addresses a long-standing limitation of previous generations of TPU: squeak. XSG delivers a quieter and more comfortable wearing experience in both athletic and everyday wear.
This advance does not come at the expense of durability. XSG maintains low abrasion loss, across a wide temperature range, where many materials begin to wear down. It also offers excellent hydrolysis resistance, exceeding five weeks in accelerated testing according to SATRA's benchmark, indicating its dependable performance in hot and humid climates.
The XSG series is available in both polyester and polyether options for different application needs.
Building circularity into the sole system
Sustainability starts with the material selection. Vulcanized rubber depends on a multi-step, energy-intensive process with long cycle times and is difficult to recycle through conventional routes at the end of life. TPU takes a different route. As a thermoplastic, it can be processed through automated injection molding with fewer processing steps, and both the material and production offer greater recycling potential. For manufacturers, that means shorter cycles, fewer tools and lower energy use compared with conventional rubber processing.
It continues with how the sole is connected. Our TPU outsoles work with direct-attach and direct soling technology. When paired with a PU midsole, they bond directly, with no primer and no adhesives. When paired with a TPU foam midsole, they can be molded in one piece, forming a sole system that supports circular economy initiatives.
Bringing our innovations into commercial footwear applications requires collaboration across the whole value chain. At our TPU Asia-Pacific R&D Center in Taiwan and our TPU Application Development Center in Guangzhou, we work from material selection through application development, from concept to production, closely with customers, offering rapid prototyping and local technical support to bring high-performance, more sustainable soles from concept to production. Together, we can make the outsole simpler, more resource-efficient and ready for what comes next.
