All About ETPU Foam for Footwear

We are in a golden age of footwear foams. From poured and open cell PUs to EVA, there are a wide variety of foams that you’ll find used in footwear—and that’s not even including those that are currently in development!

One of the most increasingly popular footwear foams is Expanded Thermoplastic Polyurethane (ETPU), a closed cell polyurethane foam. Due to its versatility and high rebound properties, ETPU foam is growing in popularity for footwear, especially in the last 5 years. Today we’re going behind the scenes of ETPU foam, and what exactly makes this foam a game-changer for footwear applications.

The Process of Making ETPU Foam 

Thermoplastic polyurethane (TPU) beads are the core ingredient of ETPU foam. This filament is known for being especially flexible, durable and lightweight. When heat and pressure is applied, the beads expand and form air pockets, creating the foam’s iconic “popcorn” structure. The combination of the physical material and the air pockets produces exceptional tear resistance and tensile strength. This is what provides ETPU’s signature and long-lasting reflexive sensation.

ETPU Foam Characteristics

Thanks to the ETPU filament and structured air pockets, ETPU foam possesses unbeatable elasticity and resilience. It’s a lightweight foam capable of high-impact absorption because the air capsules compress and bounce back when force is applied, like running and jogging. In turn, that springiness makes for high energy return.

Meanwhile, the closed cell structure of ETPU foam adds to both its durability and cushioning, so the foam can feel more comfortable and bouncier for longer.

Footwear Benefits and Applications

You can find ETPU in a growing number of insoles and midsoles because of its bounciness, durability and airiness. ETPU’s high energy return and shock absorption pair well with the material’s flexibility to provide a comfortable and dynamic wearing experience.

The durability from the closed cell structure means that insoles and midsoles retain their shapes with repeated compression and also maintain flexibility in extreme temperatures.

Lastly, ETPU can be made in a range of hardnesses, so it’s adaptable to a variety of footwear applications where you may need firmer or softer foams to achieve your desired effects.

As a result, ETPU is excellent for:

• High-performance athletic shoes, like running and basketball
• Lightweight workwear applications, such as industrial safety and specialty work shoes
• Shoes needing long-lasting, all-day comfort, like athleisure and casual sneakers
  

  Pulsion Ignite ETPU

  Interested in getting a firsthand look at ETPU for your own footwear applications? INSITE® Pulsion® Ignite ETPU footwear foam is a great option for when you need explosive momentum and energy return, especially for high impact athletic shoes. Pulsion Ignite can be used in our signature or custom 3D insole shapes, or as the bottom layer of dual-density insole.