Pad Printing Pre-Treatment
A cloud of ionized air (or corona discharge) is a common method of treating surfaces of plastics and other materials. It breaks down the molecular bonds on the surface, resulting in oxidation of the surface. This readies the surface for better adhesion, especially on tough marking surfaces such as elastomeric and polymeric surfaces.
Plasma treatment is used mainly on rubber, metals, glass, polymeric, and ceramic materials. Highly ionized air streams breaks the hydrogen bonds atop the material's surface resulting in a cleaner and better bonding exterior. A big perk of plasma treatment is the ease in which it can adhere to cover complex three-dimensional parts.
A popular method of making materials such as polyethylene and polypropylene work is using a flame treatment. A rapid and intense heat breaks molecular bonds and forms polar points on the surface of the material. This makes the surface rougher on a microscopic level, allowing better ink adhesion.