| 摘要 |
691,397. Discharging electricity from paper &c. KELLER, T. W. Oct. 30, 1950, No. 26359/50. Class 35. [Also in Groups XI and XVII] In making bags of thermoplastic material such as polyethylene by-passing a flattened tube of the material between electrically-heated devices which seal the superposed plies together at bag length intervals, and finally severing the tubular stock adjacent to the sealing lines (see Group XVII), the consequential accumulation of static electricity is neutralized by passing the finished bags beneath a device 187 immediately behind the cutting mechanism and comprising a cylindrical outer casing 188 enclosing an axially arranged rod 189 from which it is spaced, the rod being provided along its length with a series of pointed projections 192 extending radially outwardly through corresponding openings in the casing 188 towards the bags. The casing 188 is earthed and the central rod 189 connected to a source of high potential, e.g. 50,000 volts. |
