Closed Cell Foam vs. Open Cell Foam: What's the Difference?

Regardless of if you are new to our foam products or have been with us a while, you have probably noticed we provide both open-cell and closed-cell foam types. The differences between these two types of foam are important to understand. While both kinds of foam are ideal for a vast array of applications, some of the differences between open-cell and closed-cell foam may influence your choice of which foam to use. We want to share with you what makes these two foam types unique, the pros and cons of each, and clarify which foam will work best for your application.

Most Significant Difference Between Open and Closed Cell Foam

The most apparent difference between these two foams is that one type has tiny spaces, or cells, that are entirely closed and contained, whereas the other has open cells, but, let's take a closer look at comparing open cell vs. closed cell foam.

Open Cell Foam

A foam is classified as an open cell when more than half of its cells are open. Open-cell foam behaves more like a spring. When it is compressed, it can quickly return to its original state due to its unrestricted airflow. Open cell is also soft to the touch, breathable, flexible, and can easily conform to objects.

Pros of Using Open-Cell Foam:

  • Lightweight. Open cell foam typically weighs anywhere from 1.2lbs per cubic foot to 2.8lbs per cubic foot.
  • Incredibly flexible, open-cell materials can expand and contract with heat or cold when used.
  • Some open-cell foams, like our Dryfast can be used outdoors, and may retain little to no moisture.
  • Open-cell acoustic foam can help dampen soundwaves.

Cons of Using Open-Cell Foam:

  • Open-cell foams tend to have a lower R-value, and are not suitable for use in places or climates with extreme temperatures.
  • They are not always dense enough to provide rigid structural support.
  • Open-cell foams can sometimes shrink over time, depending on what conditions it is in.

Closed Cell Foam

Closed-cell foam consists of cells that are entirely enclosed by walls. Since they are closed, they do not interconnect with other cells. This foam is commonly created from a rubber compound subjected to gas, such as nitrogen, under high pressure. Closed cells can also be made by incorporating gas-forming materials into the mixture. These tiny, discrete pockets of gas make this type of foam extremely hardy and result in higher densities.

Pros of Using Closed-Cell Foam:

  • Mostly waterproof. Cells are so closely packed together and encapsulated, they leave little room for water to seep in.
  • Strong and tear-resistant, making it more durable and long-lasting.
  • Excellent insulation properties, acts as an air barrier.

Cons of Using Closed-Cell Foam:

  • Higher density, more rigid meaning it can break.
  • Lower breathability than open-cell foam.

Ideal Usage of Open Cell and Closed Cell Foam

Closed-cell foams are ideal for uses that require a sturdier option, such as in packaging and commercial uses. Open-cell foams are softer, lighter, and commonly used in comfort options such as cushions, sofas, mattresses, car seats, pet beds, and pillows.

We hope we've been able to help answer your questions about the differences between closed-cell and open-cell foam. We aim to help you make an informed decision for your next purchase. If you have further questions, feel free to Contact Us directly.