GB1424627A - Corona discharge device - Google Patents

Abstract

1424627 Corona discharge HOECHST AG 20 June 1973 [22 June 1972] 29230/73 Heading G2H [Also in Division H1] A moving sheet is charged by a corona discharge device in the form of a flexible electrode strip in a plane parallel to, Figs. 1, 2, 4 and 5, or at right angles to, Figs. 8 and 9, that of the material and moving at right angles to the material, the corona discharge being from one or both edges of the strip. The strip passes through a cleaning zone (separate from the charging zone) in which cleaning may be effected by a doctor blade or a stationary or roll brush. It may move continuously in one direction in the form of an endless belt or reciprocate between supply rolls. It may be a continuous metal or metal-coated tape or comprise discrete rigid metal elements attached to a belt Fig. 7a, b and d (not shown) or directly to one another Fig. 7c (not shown). It may be flat or shaped. It may have a longitudinal guiding and reinforcing element. Its discharge edge may be straight, Figs. 1, 2,4 and 5, saw-like, Figs. 8 and 9, or in the form of a plurality of needle points. Its discharge may be controlled by one or more auxiliary electrodes which may be stationary or moving in the same or opposite direction (relative to the main electrode). Ozone may be sucked from the discharge zone. Figs. 1 and 2 show a main electrode 1 guided between a block 20 and strip 21, two rows of stationary control needle electrodes 11 and 12, and cleaning brushes 6. Fig. 4 shows a pair of control electrodes of the same type as the main electrode. Fig. 5 shows stationary control needle electrodes 11 and 12 and further stationary control electrodes 40-44, Fig. 8 shows main and control electrodes of the same saw-edged type, while Fig. 9 shows stationary needle control electrodes 11, 11' and 12.