Corona activation is a highly efficient method used to improve the adhesion of many materials. The treatment is restricted to the surface, does not modify the material properties and is not visible. It greatly improves the adhesion of printing inks, lacquers, coatings and adhesives.
The corona process is based on an alternating electrical discharge into the atmosphere. The discharge burns in an electrode system adapted to the corresponding material. The high-energy electrons generate radicals on the material surface which mainly react with oxygen radicals which are also generated from air. The resulting chemical compounds have a lasting effect on the surface.
The most frequently used materials are plastic films made from polyethylene, polypropylene, polyamide and polyester as well as metal films made from aluminum and types of paper or cardboard.
Increasingly, natural and synthetic fibers as well as non-wovens and wovens made from those fibers are corona activated.
Special systems are available for powder, pellets, profiles, pipes, machined parts, foamed materials, stampings, formats etc.
The main assemblies are the corona station to treat the material, the corona generator to supply the medium-frequency high voltage and the exhaust system to prevent the emission of reaction products into the workspace.
Peripheral assemblies are the ozone converters for exhaust air decontamination, the remote control for control of all functions, the central control for connection to production machines and the pressure housing for explosion proof operation.
Expander rollers, pressure rollers, cooling rollers and roller drives are used as web guiding elements.
Adapted handling systems are available for machined parts.
Corona systems are always installed inline on blown film, cast film and coating machines upstream of the rewinder, and downstream of the unwinder for printing, lacquering, coating machines.