adhesion tendency

Adhesion (from Latin adhaerere 'to cling' or 'to attach') describes the adhesion between bodies of different kinds. The forces acting between atoms and molecules, the so-called molecular forces, are divided into two types: the cohesive and adhesive forces.

The cohesive force causes the atoms and molecules of a body to be held together, e.g. B. when bending a nail, the particles stick together. The greater the cohesive force of a body, the more solid it is (solid body = large cohesive force, liquids = lower cohesive force, gases = very small cohesive force).

The adhesion force refers to the attractive force between particles of different bodies, e.g. B. Ink sticks to paper, chalk sticks to the blackboard, glue sticks to wood. The strength of the adhesion forces depends on the respective material. For example, they have a particularly high adhesion force. B. Adhesives, paints and varnishes.

Adhesion tendency refers to the degree of attraction between two different bodies. If there is talk of a large adhesion tendency, the two bodies adhere well to each other (eg paint on vehicle body). If one speaks of a low adhesion tendency, the two bodies adhere badly or not at all to each other. A low adhesion tendency therefore has a non-stick effect.

The goal of a surface coating which is to have an anti-adhesive effect is therefore the lowest possible adhesion tendency between the coating and the substances or media that touch it.