| 摘要 |
The invention is concerned with an apparatus and a process for perforating synthetic plastics film, for example polyethylene or polypropylene, with an electrical spark discharge set up between a set of first electrodes which may be pointed rods and second electrodes which also may be complementary pointed rods or a single electrode which may be an electrically conducting guide plate, vane or roller. The film is drawn between the first and second electrodes. Each first electrode is supplied with high voltage sufficient to cause the spark discharge from a separate charged capacitor whereby each first electrode is electrically isolated from the others and thus a discharge from one first electrode does not prevent the formation of discharges from the other electrodes. The charging and discharge of the capacitors is controlled by a series of coupled switching units. |
