Differences in Permeability and Application between Open and Closed Cell Foams

Today, numerous industries are taking advantage of the benefits of plastic foams. The construction industry typically uses them as structure insulation or cut them for decoration purposes. Alternatively, the packaging industry utilises foam materials in protecting fragile products. Foams can also be used in reupholstering any piece of furniture.

Foams are being utilised by a lot of industries since they can effectively insulate heat, vapour, noise, and other elements. These materials can be grouped into two types. One is open cell foams, and the other is the closed cell foams. Both types of foams can be used in everyday products. However, their structural differences make them more suitable for specific applications.

Formation of Cell Foam Materials

Foam materials are usually produced by dissolving gas under high pressure into a polymer while it is in a liquid state, which causes the formation of tiny bubbles or cells in the polymer. Each foam has a unique set of properties that are intended for specific applications. In choosing between open and closed cell foams, manufacturers mustconsider the permeability of the foam material to different elements, especially on how effective they can be as barriers.

Key Features of Open and Closed Cell Foams

The formation of the cells in open cell foams is broken, making them vapour semi-permeable. Open cell foams allow air to permeate more easily, which makes them more porous and more absorbent than closed cell foams. The appearance and cell configuration of open cell foams can closely resemble the holes found on a sponge.

The cells found in closed cell foams are piled together like tiny air pockets in a compact configuration, which may look like inflated balloons that are nestled tightly. This specific cell configuration helps the closed cell foams to be vapour semi-impermeable, more rigid, more susceptible to high pressure, and is about four times denser than open cell foams.

Permeability and Application Differences

Permeability is a measure of the ability of a porous material to allow fluids or air to pass through it. With foams, their permeability highly depends on their cell configuration and other properties.

Since open cell foams have broken cell formation, they have a higher possibility of absorbing water than the closed cell foams. Withs continuous water absorption, expect your open cell foams to degrade over time. So, if you have a moist environment, it would be best for you to use closed cell foams since they do not absorb water.

Closed cell foams are also recommended in controlling airflow and preventing water vapour. These foams can be used as an effective gasket or seal as they can keep hot air from entering an air-conditioned enclosure. And since they are more impermeable to water, vapour, and air, closed cell foams can effectively prevent the occurrence of mould, mildew, rot, and bacteria.

Going back to open cell foams, they are effective as a filtration since they allow air to pass through them. Engines use this type of foams as air filters since they can help capture dust and other pollutants without restricting airflow. Aside from filtration, open cell foams are also more effective in absorbing and reducing sound. Their cell configuration allows sound waves to interact with residual membranes, absorbing some of the sound energy and subsequently transforming them into heat.

Knowing the differences between the open cell foams and the closed cell foams can help you determine the best type of foam for you. To help you choose between the foams, just contact us now at Foam Sealant. We sell quality pressure-sensitive adhesive foam tapes, single-sided and double-sided from trusted names, and our own competitively priced foam sealant range of foam tapes.