Abstract: A housing for filtering the intake air of a fuel cell, comprising a housing bottom part and a housing top part, which together bound off a space, the space being divided by at least one filter element into a crude air space and a clean air space, both the housing bottom part and the housing top part being coordinated with an air admission port to carry intake air into the space or out from the space, wherein the housing works steadily and reliably after a no-problem installation, wherein the filter element is at least partly embedded in a sealing compound.

Abstract: A filter arrangement for cleaning fuel cell supply air, including at least two filter layers, whereby a first filter layer is designed as a coarse filter and a second filter layer as a fine filter, wherein the second filter layer includes an electret filter material.

Abstract: A method of producing a filter insert (1) having folds (2) extending radially, by first pleating a filter material to form an essentially rectangular filter sheet (3) having folds (2) arranged across the longitudinal direction (4), then wrapping the pleated filter sheet (3) around a core (7), and next joining the first fold (8) and last fold (9) of the filter sheet (3) adjacent to one another in the circumferential direction.

Abstract: A filter cartridge made of an accordion fold pack folded in a zigzag-shaped manner and made of a thermoplastically moldable and heat-sealable material, whose folds are held at an adjusted, defined distance relative to each other, in particular made of a nonwoven fabric. The longitudinal direction of the accordion fold pack, transversely to the folds, the individual fold peaks are folded over in the same direction in at least one strip on one or both sides of the accordion fold pack and in each case fixedly joined to the next following, likewise turned-down fold at least in the overlapping region, by heat-sealing.

Abstract: A flexible folded filter insert which is not noticeably deformed by the air which it cleans. The insert has a fold pattern which is closed off at the ends by flexible strips which can be compressed in the longitudinal direction.

Abstract: A pocket filter includes a front frame which accommodates at least two filter bags. The top of each bag accommodates a reinforcing frame. The bags are secured dust-tight to one another, to the reinforcing frames, and to the front frame. The front frame is a severed at at least one point along its perimeter. The front frame has a U-shaped channel around it that opens inward, and the reinforcing frames can be inserted into the channel when the front frame is open at the severed point. The reinforcing frames match each other and match the size of the front frame, creating a dust-tight contact between all the adjacent reinforcing frames and the inner surface of the channel when the front frame is closed at the severed point. Facing webs, disposed in the channel opening on each side of the "U", create a dust-tight contact with the reinforcing frame.