Abstract: The invention relates to a fuel cell system (1) which is characterized in that a fuel cell stack (2) comprised of a plurality of intermediate plates is enclosed between two end plates (3) to compress the intermediate plates. At least one end plate (3) has an end plate base (4) and a contact surface plate (5) linked therewith to electrically contact the fuel cell stack. The end plate base (4) is furthermore provided with channel structures (6) designed for a cooling circuit for cooling the fuel cell stack. The end plate is deformed in such a manner that it is capable of applying an even compression to the fuel cell stack and to balance the setting behaviour of the stack and of the end plate.

Abstract: A method of making an air filter insert for cleaning the combustion air of an internal combustion engine. The method includes producing the filter insert (21) from a pleated filter medium (33) which is formed into a hollow cylinder, in which at least one end plate (33, 34) made of thermoplastic elastomer or thermoplastic polyurethane is disposed on the axial end faces of the filter medium (33). The at least one end plate (33, 34) is bonded to the cylindrical filter medium (33) by heating the filter medium or the end plate (33, 34) with a high-temperature heating element and fusing the filter medium (33) and the end plate (33, 34) to form a welded joint.