Patent ID: 7338696

Claim:
Process for producing a sandwich panel having a cellular structure having two faces, a plurality of adjacent cells opening up on at least a first face, at least one wall and an adhesive film inserted between said wall and said first face, the process comprising: punching an unperforated adhesive film in order to form at least one approximately circular hole having a diameter, wherein the punching the unperforated adhesive film is performed by at least one punch which comprises a conical end part with an angle β of between and including approximately 30° and 35°, and with an adjacent tapered part with an angle θ of between and including approximately 20° and 25°; locating the adhesive film between the wall and the first face with one hole facing each of the cells of the cellular structure; and gluing the wall to the first face, wherein the adhesive film is perforated with at least one hole facing each of the cells of the cellular structure in which the holes are formed by punching an unperforated adhesive film, and wherein the at least one hole is approximately circular with a diameter that is not uniform over a thickness of the said film, and wherein the at least one hole is tapered.