How the popcorn sole changed safety footwear forever.


Professional workers and women move their body much like an athlete. They tackle tough and repetitive conditions, so at the end of the day, what they wear makes a huge difference to their performance and health. This insight drove us to build work shoes using the same high-tech material, expanded thermoplastic polyurethane, or ETPU for short, that athletes rely on to last longer. A game changer in our industry, and since our launch of Solid Gear Revolution in 2017, we no longer offer one model but several. Making us today’s market leader.

So, let’s take a closer look at the technology, the benefits and our shoes.


Various particle foams have existed since the 1950s, but ETPU first appeared in 2010 and was an instant hit in running shoes due to its elasticity and suspension. To develop ETPU, you start by transforming its raw material, TPU with heat and high pressure to expand the tiny pellets into little beans, or closed cells, each with its own air pocket core. Now as particle-foam it passes through a multi-step industrial process to be steam molded into any desired shape, density and size, for example shoe midsoles. Every ETPU sole from Solid Gear is made from over a thousand beans. Think of it as tiny, perfectly engineered pillows each working independently, and collectively to make each step light and elastic.


TPU (thermoplastic polyurethane) is an elastomer with a blend of rubber and plastic and used anywhere you need a combination of low weight, performance and durability. The material is incredibly versatile, it’s tough, oil and grease resistance and capable to return to its original shape and size after being bent, twisted, stretched and compressed. The hardness can be customized from soft rubber-like to hard, rigid plastics. You can go transparent or colored, opt for a smooth surface or one that provides grip. The application possibilities are just as endless; from medical devices, sports equipment, power tools, wetsuits, elastic clothing, to 3D printing and footwear.

1 / 5


Your feet are your body’s natural and primary shock-absorption system. But to last a lifetime, it need assistance by shoes with strong and durable materials that performs over the long haul.

In tests, ETPU does far better compared to traditional particle foams, such as EPP, EVA, or EPE. The rebound value is significantly higher, the compressed reply is much better and you get a more efficient cushioning power. The functional properties change much less over time. The ability for the sole to return to its original shape right after impact is what make you work with more comfort. To move in style, and with safety. To last longer. ETPU doesn’t only withstand wear and tear but also stays stretchy and remain its high resilience between temperatures from -20°C to +40°C (-4°F to +104°F). So, great for summer and winter.


Nail protection, toe caps and anti-slip are features designed to protect you from external hazards. But work-related injuries are far more common than crushed toes. Fatigue, blisters, back and knee pain might be minor annoyance at first, but can quickly turn into major anguish with serious consequences. From long-term absence, project stall, lost productivity or income. Think of your shoes as your first line of defense. And by investing in a comfortable pair, you’re not only protecting your feet, but your entire body from long-term injures. It’s a health decision as much as it is a business one.

Since our first ETPU sole a few of our competitors have followed suit. But being first in Europe means more experience and more options. With us you don’t choose between comfort and no comfort. You choose a shoe fit for your profession, whether you prefer green over yellow. Blue over orange. That’s what Wired for Progress means – to always be one step ahead.

Solid Gear logotype