New investigations concerning the blistering phenomenon in rotary lip sealing have been carried out with fluoro elastomer seals with and without epidermoid layers, using different oil types and seals in different arrangements under static and dynamic conditions, including a microscopic analysis.

The test results indicate that blistering in rotary lip sealing is not only a problem of fluid compatibility but strongly refers to the thermal and mechanical load of the seal in contact with the rotating shaft. Blister-filling may be achieved in a macroscopic way without adsorption and diffusion of the sealed fluid.

This work examines the role of important factors of a blister formation in rotary lip sealing and therefore helps to analyze and prevent blistering in practical applications.