2. Membership theory

2.1 Notions of adhesion and cohesion

A distinction must be made between adhesion and cohesion (figure 4 ). The strength of a bonded assembly depends directly on :

• the internal cohesive force of the adhesive ;

• compatibility between adhesive and substrates, the ability of the adhesive to wet the surfaces of each substrate;

• the internal cohesive forces of the substrates.

Adhesion (expressed in N/m) depends on the nature of the adhesive, the nature of the substrates (more or less easy to bond depending on surface energy) and time (rise in adhesive performance)....