With sealing lip
Sealing lips are used in round filters when the pleat of the filter medium are additionally glued on the edges, forming hermetic pockets. These seals are placed on the inner edge of the cartridge, providing a kind of filter sealing in the casing and beneficial stress pattern in the filter during exploitation. The advantage of this design is a significantly smaller polyurethane seal, which is not neutral to the natural environment during used filters disposal. As far as the functionality is concerned, these filters are not different from those with traditional seal covering the whole width of pleats.
Air filter cartridge with sealing lip