METHOD FOR PRETENSIONING THE DIAPHRAGM OF A DIAPHRAGM PRESS, AND PRESS FOR CARRYING OUT THIS METHOD

Provided is a method for pretensioning the membrane of a press, including the following steps: a) providing a press having a first pressing tool, a second pressing tool and a membrane. The first pressing tool and the second pressing tool are movable relative to one another, wherein the membrane is connected to one of the pressing tools. A cavity for a working medium is formed between the membrane and the pressing tool connected thereto. The cavity is sealed by at least one seal which presses onto the membrane with a sealing force; b) providing at least one workpiece, wherein the workpiece includes a matrix and fibres embedded therein; c) inserting the workpiece into the press; d) closing the press; e) subjecting the workpiece to pressure and/or to heat by means of the membrane. A cured shaped part is formed from the workpiece; and f) opening the press and removing the shaped part. In order to ensure as smooth as possible a surface of the membrane, it is proposed that the membrane is already pretensioned before step e). Also presented and described is a press for carrying out this method.