Bonding materials - Mechanisms. Adhesive classification

Until the Second World War, materials were assembled mainly by mechanical means: bolts, screws, rivets, brazing (metals), sewing (leather and textiles). Only furniture-making and packaging made some use of gluing.

It was during this war that adhesive bonding came into its own. On the one hand, the development of new chemical products bringing new properties of adhesion, hardening necessary to control the setting of adhesives, durability, among others, made it possible to adapt this assembly technique to other applications. Bonding also benefited from the wartime development of the aeronautical industry, with American and British aircraft manufacturers beginning to use this technique for the mass production of aircraft structural components.

The gluing market then spread to other industrial sectors. As a result, the French glues and adhesives market grew from around 5,000 t/year in 1920 to 400,000 t/year in 2000.

The purpose of this article is to review adhesion mechanisms, product characteristics and general design rules, as well as the main types of glues, adhesives and sealants used for solid and permanent bonding of the main structural or semi-structural materials (metals, plastics, wood, glass, elastomers, etc.).