How does a typical corona installation look like?
The set-up of a corona discharge system generally consists of one or several high-voltage electrodes arranged at a distance of between 1 to max. 12 mm from a grounded roller. If a high voltage is applied to the electrodes, a corona discharge occurs in the gap between the electrodes and the roller, and a plasma is formed.
The electrodes and/or the roller are covered with a non-conductive barrier (e.g. ceramic, quartz or silicone), which has also given rise to the term barrier discharge. Compared with metal electrodes, barrier electrodes result in more even surface treatment and are suitable for treating conductive materials such as aluminium foils. If a plastic is guided over the grounded roller through the discharge gap, its surface becomes oxidized when this is done.