Molded Open Cell Foam Vs Closed Cell Foam Insoles: What’s Better?

by | Jan 27, 2023 | Product Design

Don’t be Closed Minded: Making the Case for Athletic Footwear Brands to Consider Closed Cell PU Foam

There is an important distinction to be made in the athletic shoe industry between molded open cell foam vs closed cell foam insoles, which are each great options for insole material and offer unique benefits for different types of footwear.

In considering the differences between molded open cell foam vs closed cell foam, each are great options for insole material and serve unique and beneficial purposes depending on the type of footwear. While molded open cell PU foam has widespread use for insoles, for the purposes of this post, we’re going to talk about closed cell PU foam and its unique benefits for athletic footwear.

As any athletic footwear developer knows, there are a few primary goals for any shoe being used for athletic activity: moisture wicking, lightweightness, support, and performance. And those qualities don’t just apply to the shoe itself, but to the insole as well.

Hence the distinction between closed cell vs open cell foam. Let’s consider some of the primary differences between these two types of materials when being used to make insoles for athletic shoes.

Closed Cell PU Foam and Open Cell PU Foam: What Are They?

Closed cell PU foam, or closed cell polyurethane foam, consists of cells that are completely enclosed by their cell walls, so no cell is able to interconnect with another cell.

Open cell PU foam, on the other hand, is composed primarily of small cells that are not closed off or completely sealed, therefore allowing air to fill the space between them, or the ability to take on and absorb water.

Knowing these key differences in the makeup of the material makes it easy to understand, then, why athletic footwear developers might have concerns about closed cell PU foam and its impact on the weight of the insole, its moisture wicking capabilities, or its support and performance capabilities.

The Support and Performance Benefits of Closed Cell Foam Insoles for Athletic Shoes

For athletic shoes, an insole that can handle any level of activity is a huge benefit. It stands to reason that a foam material that is denser, like closed cell PU foam, would provide greater support and performance benefits.

We’ve broken down the ways in which closed cell PU foam can enhance an athlete’s experience with your footwear.

  1. Better Shape Retention: Insoles made using closed cell PU foam are able to retain their supportive shape for longer, meaning your customers get more use out of your footwear.
  2. Better Shape Support: Closed cell PU foams can support a broader range of insole shapes, such as arch support shapes, heel cups, and more.
  3. Greater Impact Protection: A denser foam can better support the impact placed on the insole during more rigorous activities like running and jumping.
  4. Excellent Rebound: Closed cell PU foams can recover more quickly from compression (such as a long run) and “bounce back” to provide the necessary support and comfort more quickly than with an open cell PU foam.
  5. Cushioning Quality: INSITE closed cell PU foams can be designed to complement the cushioning of human foot tissue, reducing discomfort and providing a better overall experience for wearers.

Other Benefits of Closed Cell PU Foam for Athletic Shoe Insoles

If you are a footwear developer with concerns that closed cell PU foam is heavier or less moisture wicking than open cell PU foam, you might be surprised to know that these statements are actually not accurate – in fact, closed cell PU foam is only a few grams heavier than open cell PU foam – such a small weight difference that most end consumers wouldn’t experience any negative impact.

Similarly, there is no substantiation for claims that closed cell PU foam has any less capability for moisture wicking than open cell PU foam. Closed cell PU foam is generally good at moisture wicking because the cells are tightly compacted enough that moisture isn’t able to get in-between them. In particular, INSITE closed cell PU insoles have shown to be excellent for both work and athletic applications with great results.

Two Great Insole Foam Materials With Specific Footwear Benefits

Open cell PU foam insoles and closed cell PU foam insoles each have qualities and benefits that make them ideal for different types of footwear applications.

And while closed cell PU foam offers excellent support, performance, moisture wicking, and weight benefits for athletic shoes, open cell PU foam also offers benefits for athletic footwear. That’s why INSITE offers a “best of both worlds” dual density insole, with a bottom layer of molded closed cell foam for high performance, and a middle layer of open cell foam for added breathability.

Depending on your footwear line and the activities your athletic shoes are designed for, we can work with you to determine if a closed cell PU foam or dual density foam insoles are your best option to give your customers an exceptional experience during activity.

Benefit your customers, your footwear, and your brand with the right type of insole foam material for your athletic shoe line.

What’s the best foam material for your athletic shoe insoles?

Insole Insights