buoyance of natural cork is used to good effect in petrol and oil level gauges, but the most important application of cork in the automotive industries is in cork-and-rubber gaskets. Today, these are as essential as petrol or diesel fuel to the car and truck industries. The material used combines the compressibility and resilience of cork with the high mechanical strength and dimensional stability of rubber, making them the best substances of such automotive applications as oil pan gaskets, valve cover gaskets and timing gear cover gaskets.
Another important application of cork-and-rubber is as a seal to retain lubricants in crank shaft bearings. When pressure is applied the air within cork cells is compressed, thus exerting a reverse pressure on the restraining faces. This is termed 'fight back' and is a primary requirement in all good gasket materials. Cork-and-rubber can be cut easily, and because it is strong and flexible, it can be used for making gaskets with narrow flanges.
A wide variety of formulations are used for making gaskets with narrow flanges. Natural Rubber, Synthetic Rubber, Nitrile, Neoprene, EPDM Silicone and sizes of cork granuals are available to meet the industry's various requirements. For the electrical industry, special cork-and-rubber have been developed to prevent leakage of the very searching cooling fluids used in modern electrical transformers. Similar materials are also widely used in switch gear circuit breakers, lightning arresters, and other transmission equipment, as well as in conduit fittings, gear cases and cover plates in washing machines.