Closed cell foam is a strong, flexible material that's made up of internal pores, or cells, that sit closely together but are not connected. Its structure can be compared to a net filled with balloons, where the balloons are trapped tightly against each other, but they are not interconnected. It's a versatile material that can be used in everything from crafts to construction. The six basic types of closed cell foam are polyethylene, Styrofoam™, Volara®, Minicel®, neoprene, and gymnastic rubber.
All types of closed cell foam are known for their high structural integrity, high compressive strength, and low moisture absorption. It is lightweight, flexible, and firm, and resists most solvents and chemicals as well as fungi and mold. Durable enough to withstand a large amount of pressure without major distortion, it's stronger than open cell foam, but also requires more material, which makes it more expensive. The ways in which the foam is used varies depending upon the type.
Strong and resilient, polyethylene foam is often sold as closed cell foam sheets. It is used as thermal insulation, as shock absorption, to dampen sound, and as cushioning. It is very buoyant and is frequently found in flotation devices and other nautical equipment.
Polystyrene, also called Styrofoam™, is a lightweight foam that is easy to work with. It is used in construction as insulation because of its almost complete resistance to moisture, water vapor, and mold. It is also a popular choice for arts and crafts and packing material.
Volara® is a thin foam with has a smooth consistency, gauge control, and low water absorption and vapor transmission. It is generally found in refrigerators and freezers or used as poker table padding. It has also been used a good deal in the auto industry.
Minicel® is a thick closed cell foam that has a smooth feeling. It is commonly used for shock absorption and padding and may be used to cushion sporting equipment like football helmets. It is also used in flotation equipment and airplane seating.
Neoprene is a flexible and durable sponge rubber. It is form-fitting and offers insulation from heat, cold, and moisture. Neoprene can also resist breakdown by water, along with ozone, sunlight, oxidation, and oils. Some of the many uses of neoprene include orthopedic braces, wetsuits, waders, and gloves.
Gymnastic rubber is durable, flexible, resilient, and resistant to most liquids. As its name suggests, this type of closed cell foam is often used in exercise mats, camping pads, boat cushions, and floor padding. Its squishy consistency makes it a good choice as padding.