There is provided a cooker hood and a method of manufacturing the cooker hood. The cooker hood comprises a roof (20) and sides (10, 12, 14, 16) that descend from the roof. The method comprises providing a first metal sheet (100) that forms the sides of the cooker hood, the first metal sheet having upper and lower lengthwise edges opposite from one another; providing a second metal sheet (200) that forms the roof of the cooker hood, the second metal sheet having peripheral edges; folding the first metal sheet across the width of the first metal sheet to define differing ones of the sides of the cooker hood, and subsequently joining the upper lengthwise edge of the first metal sheet to the peripheral edges of the second metal sheet.

There is provided a method of producing acoustic damping elements having an acoustic resistance. For that purpose at least one sleeve with a hole having a diameter is placed below a base material. At least one hole is stamped in the base material by at least one punch having a punch diameter. The punching operation is repeated at various positions on the base material.

Disclosed is a multi-layered composite panel. The multi-layered composite panel comprises at least two sheets of thin plates with continuous waveform patterns having the same pitch and different heights in one direction are overlapped. In the multi-layered composite panel, an air layer is formed between the overlapping thin plates, orthogonal pressing portions, which divide the waveform patterns on the top and the bottom of the thin plates into the unit of triangle-patterned cell by being pressed orthogonally to cross each other on the top and the bottom of the thin plates overlapping in the orthogonal direction crossing the direction of the waveform patterns, are formed and an undercut portion is formed by pressing the centers of both sides connecting a groove and a ridge of each cell on the top and the bottom of the thin plates with opposite orthogonal pressing portions.

A gutter guard apparatus and method of making the same is disclosed. In some embodiments, the gutter guard apparatus is made from at least two different types of materials, thereby enabling, for example, lighter weight, non-conductive plastics that are best suited for coupling to an existing rooftop gutter system in a corrosion preventing manner to be employed while at the same time providing for a central portion spanning the gutter opening made from a more durable material (e.g., lightweight expanded metals). The gutter guard apparatus may be manufactured by a variety of means, including a desirable, low-cost, and highly effective co-extrusion process through which end portions are extruded from raw materials of different colors into desired configurations and simultaneously extruded onto and effectively integrated with the central portion formed from a different material, thereby creating a unitary gutter guard apparatus that desirably incorporates two or more materials.