Leather is probably the oldest of the lip materials still in common use, but the move towards mass production methods has seen a massive increase in the development of synthetic rubbers which lend themselves to accurate and repeatable injection and compression moulding. Nitrile (NBR) is still by far the most common elastomer for “normal” use, whilst Viton® (FKM/FPM) is rapidly replacing Polyacrylate (ACM) and Silicone (VMQ) for high-temperature applications. Viton® also has high resistance to abrasion and chemical attack making it a preferred elastomer. Recent developments in the use of PTFE for Rotary shaft seals has caused widespread interest particularly for high-speed shaft rotation or poor lubrication applications.

These seals are more commonly used in pumps, motors both electric & hydraulic, gearboxes & occasionally dirt wipers in hydraulic cylinders. They help protect shafts and bearings from dirt and harmful contaminants entering the internals of the application that they are fitted to, as well as prevent any leaks of lubricant.

If you are looking for the highest temperature resistant oil seals, Perfluoelastomer can go up to 600°F. If you are more concerned for low temperature, Chloroprene can go all the way down to 40°F, which is why it is used most commonly for refrigeration. And if FDA applications or medical devices are your primary concern, Butyl , the all petroleum compound, will be your best choice. As you can see, when choosing the right material to work with, you must analyze several other key components to help choose the right one.