Corona treatment

Eisby came up with the theory that a high frequency corona discharge would provide both a more efficient and controllable method to treat the surface.

[2] Polyethylene, polypropylene,[3] nylon, vinyl, PVC, PET, metalized surfaces, foils, paper, and paperboard stocks are commonly treated by this method.

[4][5] Corona discharge equipment consists of a high-frequency power generator, a high-voltage transformer, a stationary electrode, and a treater ground roll.

The treater station applies this power through ceramic or metal electrodes over an air gap onto the material's surface.

However, manufacturers who treat a variety of substrates on the same production line may choose to use a Bare Roll treater.

Therefore, many surfaces will require a second “bump” treatment at the time they are converted to ensure bonding with printing inks, coatings, and adhesives.

Both treatments may use one or more high voltage electrodes which charge the surrounding blown gas molecules and ionizes them.

An increased rate of ion bombardment occurs which may result in stronger material bonding traits depending on the gas molecules used in the process.

This treatment requires higher temperatures so many of the materials that are treated with a flame plasma can be damaged.