Friction is NOT Your Friend - Slipper Can Be GOOD!
Rubber seal products like O-Rings are used in a wide variety of different applications.
The most common elastomers, Nitrile (Buna) or EPDM (EPR) are generally suitable for dynamic applications but will typically have a higher than normal break-out or running friction without the use of internal or external lubrication.
Silicone and Fluorosilicone are typically used in fuel or high-temperature applications but have very poor tensile strength and are not recommended for any high rate dynamic applications.
Fluorocarbon (Viton®) offers improved breakout and running friction over the other elastomers and some of the best high temperature and chemical performance.
External lubricants such as silicone base greases or barium base greases can be applied to O-Rings and can provide the best initial reduction in break-out or running friction. Key issues to consider, before utilizing an external lubricant include chemical compatibility of the elastomer.
Internally lubricated compounds have a friction reducing agent mixed with the elastomer that is designed to be chemically incompatible with the elastomer, causing the elastomer to continually exude the lubricant. Like external lubricants, it is critical to verify that the internal lubricant chosen will be compatible with the system fluids.