cardboard

During the production of graphic cardboard, medium grammage paper is glued to both sides of the base sheet. Graphic cardboard is used for e.g. book- and binder backs and puzzles, and must show excellent flatness and the ability to remain very flat.

In case of solid cardboard, different types of paper or cardboard are glued to the base sheet (e.g. bleached kraft paper or gold foil). Solid cardboard is widely used in the packaging industry. An example is tomato boxes, for which the requirements are water resistance and flatness.

Corrugated cardboard is produced by allowing paper to pass over preheated corrugater. The core sheet is adhered to either one or between two paper sheets. The breadth of the corrugated layer and the number of layers determines the strength of the corrugated cardboard. Corrugated cardboard is glued together by gelatinising starch. Cardboard adhesives are usually applied by means of a two-roller system. Occasionally a wire wound applicator is used.