Method and press for introducing a deformation pattern into a sheet

A method for introducing a deformation pattern into a sheet by using at least one tool unit of a press to produce an electrolyser plate or fuel cell plate, wherein

• a. the deformation pattern in at least one sub-area has a plurality of identical pattern units lying beside one another with a pattern spacing in at least one pattern direction, and
• b. for deforming only the at least one sub-area the press comprises a tool unit, in which an upper and a lower forming die are arranged, interacting deformation structures of the forming dies forming in the sheet at least one pattern unit of the at least one sub-area in a single stroke of the tool unit as the sheet is guided between the forming dies, and
• c. between two successive strokes of a predetermined total number of strokes of the tool unit, the sheet is transported onward within the tool unit in a conveying direction corresponding to the at least one pattern direction, and
• d. in the tool unit, with each stroke of the predetermined total number, the deformation pattern introduced into the sheet is supplemented by at least one of the pattern units until, after the predetermined total number of strokes, the sub-area of the deformation pattern has been completed, and
• e. with each stroke of the tool unit a positioning opening is die-cut in the sheet and a positioning pin is provided in the tool unit or the press, and before and/or with a closing movement of a stroke of the tool unit, the positioning pin moves into the positioning opening, and
• f. the positioning opening is arranged in a predetermined area of the sheet, subsequent, additional die-cutting step being carried out with another tool unit of the same press or another press in the predetermined area, wherein the positioning opening is removed by a die-cut made in the subsequent, additional die-cutting step, the die-cut thereby formed having a fluid-guiding function in a pack of a plurality of the electrolyser plates or fuel cell plates.