What is Foam or Sponge?

Is there any deference between Foam or Sponge?

The definition of a Foam:

1. Foam is a substance where air or gas bubbles are trapped in a solid or liquid. Such as froth on beer, shaving foam. Foam plastics or rubbers

The definition of a Sponge:

1. Any of numerous aquatic, chiefly marine invertebrate animals of the phylum Proliferate, characteristically having a porous skeleton composed of fibrous material or siliceous or calcareous spicules and often forming irregularly shaped colonies attached to an underwater surface. Natural sponges are in this class.
2. Porous plastics, rubber, cellulose, or other material, similar in absorbency to this skeleton and used for the same purposes.

As is probably evident, the distinction between foam or sponge is confusing and even to the extent that there isn’t really any difference

No matter how you want to call them foam or sponge, it is a plastic or rubber material that is produced via one of the following processes

1. Injected with a gas during the liquid phase before solidifying
2. Chemicals such as blowing agents giving off known gases create the cells
3. A chemical reaction creates gases within the process

It is far easier to define these materials as Open Cell or Closed cell

Open cell foams

These are pretty much 80% open cell with about 20% closed cells, although through a special process called Reticulation, these extra cells get exploded to create Reticulated Foams which are 100% open cell……. this will be discussed in greater detail on its own. Open cell foam is good where softness and comfort, or a degree of liquid or gas penetration is required or low value protection.

Closed cell foams

These are products in which the gases are completely enclosed within a bubble, be it a fine or coarse structure. This type of material has a function of not being permeable, so things like liquids or gases cannot penetrate and make them ideal for seals, gaskets, shock absorbers, thermal insulation and others.

Most of our EVA foam is Closed cell foam, unless customer required an open cell EVA foam

These foam or sponge products can be modified to create different grades during the manufacturing process; which makes things a little strange, such as semi-closed cell grades. This can be explained at a later date.

Please check out our website www.morevafoam.com for more information on our range of Open and Closed cell foams or sponge.