Abstract: A high efficiency air filter assembly (100) for high temperature applications including: a filter core (102) including a unitary sheet of air-permeable filter media folded in accordion fashion to form a plurality of side-by-side pleats with zig-zag edges on two opposite sides and flat panels on the other two sides, and a spacer member between opposing walls of successive pleats, a box-like metal frame (108) enclosing said filter core on four sides in air tight engagement to define an air flow opening extending between upstream and downstream sides of said assembly, wherein the zig-zag edges of the unitary sheet of air-permeable filter media are sealingly embedded in a solid inorganic sealant composition (118) in the frame, and wherein the unitary sheet of air-permeable filter media preferably consists of a binder-free glass or mineral fiber filter media.

Abstract: A high efficiency air filter assembly (100) for high temperature applications comprising: a filter core (102) including a unitary sheet of air-permeable filter media folded in accordion fashion to form a plurality of side-by-side pleats with zig-zag edges on two opposite sides and flat panels on the other two sides, and a spacer member between opposing walls of successive pleats, a box-like metal frame (108) enclosing said filter core on four sides in air tight engagement to define an air flow opening extending between upstream and downstream sides of said assembly, wherein the zig-zag edges of the unitary sheet of air-permeable filter media are sealingly embedded in a solid inorganic sealant composition (118) in the frame, and wherein the unitary sheet of air-permeable filter media preferably consists of a binder-free glass or mineral fiber filter media.

Abstract: A backing net for a filter media is disclosed. The backing net includes a plurality of longitudinal beams and at least one cross beam. The height of at least one of the longitudinal beams varies along the length of the longitudinal beam such that said height is reduced towards the first end thereof. A filter media and a V-type filter including such backing net are also disclosed.

Abstract: A backing net for a filter media is disclosed. The backing net includes a plurality of longitudinal beams and at least one cross beam. The height of at least one of the longitudinal beams varies along the length of the longitudinal beam such that said height is reduced towards the first end thereof. A filter media and a V-type filter including such backing net are also disclosed.

Abstract: A method for the fabrication of a filter in a frame where a pre-formed pleated filter matrix is inserted into an injection mold tool. Then a suitable elastic thermoplastic material is injected into the tool. The amount of elastic thermoplastic material injected is less than the available space between the filter matrix and the tool so that the pressure will rapidly drop as the material flows from the point of injection.

Abstract: Method for the fabrication of a neat front side of a filter where the front side is inserted into an injection mold tool. Then a suitable elastic thermoplastic material is injected into the tool. The amount of elastic thermoplastic material injected is less than the available space so that the pressure will rapidly drop as the material flows from the point of injection. By injecting the elastic thermoplastic material into a gasket part this can be given an exact shape. At the same time the free front of the elastic thermoplastic material will secure that the pressure exerted on the filter matrix will not destroy this.

Abstract: An air filter unit comprising a first sheet of filter material folded into a zig-zag configuration with a generally planar second sheet of fine mesh air penetrable material extending across apexes of the zig-zag fold on one or both sides of the filter. The second sheet includes peripheral portions which are folded up against the lateral edges of the first sheet to facilitate mounting of the filter unit within a frame.