Treatment of paper, cardboard and paperboard

[German version]

The properties of paper, cardboard and paperboard are sometimes considerably improved by special treatment methods. The aims of these treatment methods are, for example, to increase tearing and wet strength, impermeability to fat and moisture or to repel microorganisms. The following table shows three of the most important treatment methods:

Treatment method	Aim
Impregnation	Impregnation involves saturating paper products with waxes, dissolved salts or similar substances, so creating a protective layer which provides protection from insect infestation and rot. Impregnation may also render paper products impermeable to moisture and fat and also flameproof them.
Coating	The purpose of coating paper products is primarily to achieve moisture and fat repellency. Common coating materials are plastics and waxes, which are applied, for example, by brushing or other coating methods.
Lamination	In packaging applications, lamination is the bonding together of two or more plies of different packaging materials. In contrast with coating, lamination involves the application of pre-formed, flat products (films etc.). Lamination is principally performed with adhesives, waxes, latex products and polyethylene compounds. Lamination provides a protective layer on the paper products and moreover combines the various positive characteristics of the packaging materials used.