The Difference Between Open and Closed Cell Foam

What’s the difference between open and closed-cell foam? Of all the differentiators that can be made between different classifications and types of foam, the difference between open-cell and closed-cell foam is one of the most distinct, and understanding these differences can help you make the best decisions when choosing a type of foam for your applications. 

These are the primary definitions and differences between open and closed-cell foams. 

What is Open-Cell Foam?

Open-cell foam is a soft, resilient foam that is used in a variety of applications. It gets its name because it is made up of cells that aren’t fully encapsulated. The cell walls are deliberately left open in order to allow air to flow through them. This results in a lighter, less dense foam that is soft to the touch and provides excellent cushioning and shock absorption. This makes open cell foam ideal for applications like: 

  • Packaging for small and sensitive products (circuit boards, CPUs, microprocessors, and medical devices) 
  • Cushioning (mattresses, seating, pillows, and bed wedges) 
  • Orthotics 
  • Athletics (wall pads, pit foam blocks, landing mats) 
  • Fenestration 
  • Filtration 

Open-cell foams are also more viscoelastic, which means they tend to return more easily to their original shape after a force has been applied to them (think memory foam). The two major types of open-cell foam are Ether Polyurethane Foam and Ester Polyurethane Foam. 

What is Closed-Cell Foam?

Closed-cell foam is much more structurally rigid and dense foam because the cells within the material are closed off and encapsulated. This makes the foam not very breathable, but it still provides ample cushioning, just in a different way. Closed-cell foam is more ideal for: 

  • Packaging of heavier, more dense items 
  • Insulation 
  • Sound dampening 
  • Gaskets and seals 
  • Marine applications 
  • Waterproofing 
  • Outdoor seating 

The major types of closed-cell foam include: 

  • Polyethylene Foam 
  • Beaded Polyethylene Foam 
  • Crosslinked Polyethylene Foam 
  • Expanded Polystyrene Foam 
  • Neoprene 

When Should You Use Closed or Open-Cell Foam?

This depends on your application. While both foams are durable, have high tensile strength, and offer protection/cushioning, they are not meant for any application. There are also many types of foams within these two classifications, so it’s not as simple as picking open or closed-cell foam for your application. 

At Amcon, we stock hundreds of types of foam materials and can help you choose the best ones based on your products, their applications, and your budget. Need help selecting the right foam? Get in touch with us today.