Corona is a visible electrical discharge which occurs when a high voltage, high frequency electrical potential is applied to a small diameter electrode in relatively close proximity to an electrical ground. The resulting electrical discharge is known as a "Corona Discharge". This corona discharge will cause partial ionization of the surrounding atmosphere and can be used for surface modification.
How does Corona Treatment work?
To obtain good adhesion to materials that have a low surface energy i.e. low or non-polar materials like PP, PE, HDPE etc. we create a high voltage, high frequency electrical discharge or corona discharge in close proximity to the part to be treated. This high energy corona discharge is attracted to the material severing the molecular bonds on the surface. These severed bonds are now free to attach to free radicals and other particles that exist in the highly active corona discharge environment. The resulting formation of additional polar groups on the material surface have a strong chemical attraction to inks, paint, coatings, adhesives etc. leading to significantly enhanced surface energy and therefore adhesion.