A bond fails if either the adhesive separates from the substrate or the adhesive breaks apart. In cladding industry the adhesive strength of the adhesive must be firm enough so the cohesive strength of the bond fails before the adhesive one. So ‘adhesion’ and ‘cohesion’ are both keywords. The difference between them is that adhesion refers to the clinging of unlike molecules and cohesion refers to the clinging of like molecules.
