by | Feb 24, 2022 | Sustainability

When it comes to insoles, there’s no denying the market dominance of open cell PU foams. Open cell PU foam balances airy comfort with breathability. Its die-cut applications make it easy and affordable for developers to incorporate into their new and existing footwear lines. 

Plenty of insole companies provide open cell PU foam. But only INSITE goes the extra mile when it comes to both ergonomic comfort and sustainable materials.

INSITE open cell foams are made with up to 25% plant-based content — more than any other open cell foam on the market today. Not only does this plant-based content help to reduce your carbon footprint, but it also enhances the overall performance of the insoles. Our plant-based open cell foams show that you never have to compromise between sustainability, durability, and comfort.

Open Cell vs Closed Cell Foam  

As the name implies, open cell foam consists mostly of cells that aren’t completely encapsulated. Compared to its closed cell cousin, open cell foam allows more air to flow through the foam, making it more breathable and moisture-wicking. Open cell foam can be engineered for higher softness while still maintaining a strong compression set. It also offers simple insole solutions for footwear developers, with a variety of molded and die-cut possibilities. 

How Are INSITE Open Cell Foam Insoles Made?  

INSITE open cell foams substitute one of the main ingredients in polyurethane with bio-propanediol (bio-PDO). Bio-PDO is made by fermenting glucose from industrial field corn. More than just a simple filler or additive, this bio-PDO is a fundamental part of the reaction that creates the foam. The result is a stronger blend of plant-based material that enhances the foam’s overall performance. 

How does that compare to plant-based compounds in other foams? Many competitors turn to castor oil to reduce their carbon footprint. But unlike bio-PDO, castor oil is a filler that does not provide significant performance benefits. INSITE open cell foams are built using a more integral chemical process — with bio-PDO compounds that demonstrate even more comfortable physical properties. 

How INSITE Plant-Based Open Cell Foams Perform 

At INSITE, our mission is ergonomic underfoot comfort, built on data and biomechanics research. That applies to more than just our patented shapes. It applies to our foam formulas as well. 

During testing, our plant-based open cell foams outperformed traditional and castor-based foams in tensile strength, elongation, and tear strength. This is thanks to the longer hydrogen bonds in bio-PDO, giving the foam more rebound and flexibility. As a result, we can build our foams lighter and more durable, offering remarkable comfort that lasts the full life of the shoe. 

The INSITE Sustainable Difference 

Of course, the biggest reason for the bio-PDO insole revolution is the reduced impact on the environment. Based on a peer-reviewed life cycle assessment from 2019, our bio-PDO compounds were found to reduce CO2 emissions by 48%, and non-renewable energy use by 46%, compared to the petrochemical alternatives they replaced. 

Adding INSITE plant-based open cell foam insoles to your footwear line can help you meet your sustainability metrics, while still providing lab-tested comfort benefits to your customers.


See How INSITE Fits In Your Shoes 

The great news is that INSITE has engineered plant-based open cell PU foams at a similar price point to the traditional PU foams you’re using today. Get in touch with INSITE and request samples of our plant-based open cell PU foams, and take your first steps towards greater sustainability.

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Insole Insights

Sustainability Squared: Plant-Based Insoles that Last

Sustainability Squared: Plant-Based Insoles that Last

Combining sustainability and durability in the footwear industry is no easy feat, but at INSITE, it’s the cornerstone of everything we do. Read on to learn more about how our EcoComfort foams enhance our insoles’ performance.