Corona treating is a method of increasing the surface tension of most types of materials. Although you cannot see the treatment effect with you eye, after treatment the surface of the material will have become receptive to a wide range of inks, adhesives and other coatings.
Corona treatment works by exposing the surface of a material to an electrical discharge, often called a corona. It is in the discharge area that oxygen molecules break up into their atomic form and bond to the ends of the molecules in the material being treated. It is this process that chemically activates the surface of the material. It should be understood that the treatment is not permanent and will degrade over time depending on the material and storage conditions. The best places for installation are in-line on your press and if blown film on the extruder itself, as fresh material is much more receptive to being treated. Virtually any material can be treated such as foils, paper, polyethylene, vinyl, paperboard, pvc and many more.