Cork and rubber gaskets are commonly used in sealing flanges where there is contact with oil, fuel or natural gas and where bolting pressure is somewhat low. Both cork and cork/rubber gaskets are excellent when mating surfaces have possible imperfections or don't perfectly mate as they will conform to the surfaces.
Benefits of Cork
When most people think of cork, the top of their favorite bottle of wine comes to mind. However, cork has long been used is gasketing applications. Cork comes from the bark of the Cork tree, which is found in the Mediterranean. When used in gasketing, the cork is ground into pieces and bound together using a “binder.” The binder can be a simple glue or resin, or can incorporate rubber, carbon or other materials that carry additional benefits.
While less popular than other gasket materials, cork does offer certain unique benefits. For example, it is:
- Natural and lightweight
- Extremely compressible
- Excellent memory when pressure is removed
- Highly abrasion resistant
- Fire retardant
- Highly water resistant
- Low conductivity to heat, noise & vibration
- Sustainable - the cork trees regenerate after bark is harvested
Benefits of Cork Rubber
When used for gasketing, cork is very resilient, meaning it can be compressed in one direction without losing dimension in the other direction. Cork is commonly blended with rubber granules when used in gasket applications. The proportion of cork vs rubber varies with different blends. The most common rubber used in this material is nitrile, neoprene and a blend of various rubbers. The rubber choice is typically dependent on the application and what the product will come in contact with.
The benefits of using rubber with cork are:
- Rubber makes the cork denser and eliminates pathways that can cause leaks
- The choice of rubber can control the swell of the material to provide an optimum seal. The choice of rubber is also determined by the chemicals or oils that the product will come in contact with.
- Rubber makes the cork more stable
- Rubber extends the shelf life of the material
Cork and Cork Rubber Materials:
- Cork Composition
- Cork Friction
- Cork and nitrile/neoprene/rubber blends