| 摘要 |
The band (16) does not rest against the counter electrode over its entire surface area. Preferred features: The circumferential area of the counter electrode (17) includes grooves running radially and/or axially, forming a regular pattern, at least locally. The pattern extends transversely across the material advance or shows no preferred orientation. Grooves are distributed in similar or diverse patterns on the counter electrode. A non-cutting process forms them, e.g. roller threading or knurling. Characteristic spacing between grooves is less than 1.5 mm. The wrapping angle is 10 deg at least, preferably 50 deg - 180 deg . A suction device (51) below the treated band is attached directly or indirectly to the casing. For pretreatment of non-conducting bands, grooves are formed directly in the conductive circumferential surface of the counter electrode. For pretreatment of conductive or partly-conductive bands, the high voltage counter electrode has a dielectric circumferential surface including grooves. The conductive or part-conducting material is at earth potential. Counter electrode bearings are insulated. Ahead of the counter electrode there is an air nozzle (52). The material approaches at one angle, leaving at another. Immediately following departure from the counter electrode, there is a further electrode (18) opposite the material.
|
