| 摘要 |
To avoid complicated drilling or punching tools, according to the invention holes are produced in foils of thin porous materials, e.g unfired ceramic foils, using compressed air. For this purpose, use is made, for example, of an apparatus having a lower part which carries all the necessary holes of a grid. An overlying mask has only those holes which are required for the particular application. The foil to be perforated lies, in a correctly fitting manner, on top of this mask under a lid-like upper part with compressed-air connection.
|
