Foam products take many forms, but all are made by trapping gaseous bubbles in a liquid matrix. When it is cured, the end result is an extremely complex system of polydisperse bubbles separated by draining films. Depending upon the chemicals and manufacturing process used, the product may be water repellent or highly absorbent, and will also vary in hardness.

Sponge rubber may be either closed or open-cell in structure. The open-cell type consists of interconnected cells which allow the absorption and circulation of liquids and gases. This absorbency means the product should not be used where resistance to penetration by fluids is a necessity, unless it is protected with a surface coating. The reason we say this is because it isn’t always immediately obvious how absorbent open-cell sponge foams are; rather than being porous, the outer surface is continuous. However, this gives them good physical durability.

Owing to the fact air can pass freely between the cells, open-cell sponge foams are not memory foams. Instead, they display a high degree of compressibility, followed by rapid recovery from compression. This means they can be “wrung out” quickly – ideal for use as cleaning sponges.

Sponge rubber is generally made from polyurethane, although natural latex is also used (natural foam rubber makes a very durable and absorbent mattress material.) As with all foam materials, it is manufactured with a foaming agent, creating an air-filled matrix.

One method of producing natural sponge rubber is via the Talalay process, a complex method of producing natural latex shaped foams which was first used in the 1940s. Some of the products we at Technical Foam Services sell are still made by this process.

Tags: foam cut to size, memory foam, Rubber, Sponges

This entry was posted on Friday, August 27th, 2010 at 10:32 am and is filed under Rubber. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.