US Patent 7261757 Slip-rib filter gasketing

There is provided a framed filter for insertion into a filter housing having a frame surrounding at least part of a filtration media with a fluid inlet face and a fluid outlet face, the frame comprising at least one longitudinally extending sidewall portion provided with one or more flexible side seals which side seal is provided with at least one longitudinally extending rib extending in the lengthwise direction of the seal on an outwardly facing surface of the seal.