Sliding friction of the seal-shaft contact is one of the main contributors (up to 70%) to the energy dissipation in many bearing applications such as wheel hubs for cars and trains. This is mainly a result of the fact that the friction coefficients (μ) in seal applications are quite high and lie typically in the range of 0.2-0.7. Therefore, seals with significantly reduced friction coefficients would be advantageous.
Similar arguments are valid for other applications that have sliding surfaces such as sliding bearings (plain bearings), stern bearings and the sliding contacts in linear actuators.
As the contact pressures in seals are significantly lower than in the steel-steel contacts one usually finds in bearings, it is possible to look for alternative lubricants to traditionally applied oils and greases.