| 摘要 |
1. A method of perforating or of perforating and cutting the walls of hollow bodies made of plastic, said bodies being capable of running true or of presenting rotational symmetry, in particular reels such as textile tubes, characterized in that the hollow body (2) to be perforated is rotated and the points where it is to be perforated are repeatedly punctured by a plurality of needles (8) and the puncture action is repeated in succession at a frequency and with a rapidity such that the tips of the needles (8) in each case repeatedly entering holes being formed heat themselves by friction and make perforations from initially small holes. |
