Abstract: An improved wire corona charging apparatus and processes for treating webs and films, to improve surface wettability characteristics and other surface properties, and to create permanently charged electrets. Corona produced by wires results in more evenly distributed ion flux under a high level of control, than possible with commonly used bar chargers. Wire chargers are not used in applications that involve webs and films of large width, since at these widths wires can slacken and break, resulting in possible electric shorting that can be a safety hazard in most non-batch processes. The embodiments disclosed overcome these reliability and safety issues.