Flexible Graphite

The Story Behind Flexible Graphite

Some sources say that an enormous deposit of graphite was discovered in Borrowdale Parish, England, around 1500. At the time, graphite was used as a refractory material to line molds for cannon balls, resulting in rounder, smoother ammunition that could be fired further, hence the growing superiority of the English navy.

But a half century ago, it was graphite flake that inspired Union Carbide to make a product that was “flexible” and had all the characteristics of graphite. It displayed properties of thermal stability, thermal conductivity, was naturally lubricious, and resistant to most chemicals; but it was flexible, compact, conformable to any cavity, and extremely resilient.

In 1985, EGC created Thermafoil®, a material that is controlled by specification and in which vendor selection is critical. Thermafoil is processed from naturally occurring graphite which is chemically treated to form a compound between layers of structured elements. This intercalation is then heated rapidly to a state of decomposition resulting in an eighty-fold expansion (exfoliation) in size when compared to raw flake and creating a worm-like structure which is molded or calendared into sheets.