Rubber types seal integrity

Type PP Integral contact seals. These constructions usually consist of a synthetic rubber hp seal or a felt seal held by a pressed-steel member that is fixed in the bearing outer ring.The rubber lip seal is a popular design for prelubricated standard-width ball bearings. 

Contact seals. The most common types for prelubricated bearings are integral rubber lip or felt contact seals. For open-type bearings, external commercial cartridge seals or packings are mounted outboard of the bearings. These are usually standard components made by several manufacturers. 

---