Adhesives can be classified on the basis of chemical composition [29], setting mechanism [30], and adhesion mechanism as pressure-sensitive, adhesion, and diffusion adhesives [31]. Lucre [32] proposed a flexible classification in which each adhesive is characterized and classified according to various characteristic features, such as chemical basis, form of application, application temperature, thermal behavior, and uses. A classification such as this provides for very detailed coverage of the individual features of an adhesive and is a helpful guide for industrial users. However, it is extremely comprehensive and goes beyond the scope of this treatise. For this reason, a classification based on the setting mechanism is given here [30].
I. Setting without Chemical Reaction. The high molecular mass bonding substance is present prior to bonding.
I. I. Application without Volatile Solvents. The adhesive film is obtained by the action of heat.
Hot-melt adhesives, e. g., ethylene — vinyl acetate copolymers, polypropylene, polyamides, polyesters. Uses: paper, fiberboard, plastics, textiles, leather (assembly bonds).
Plastisol Adhesives. PVC or poly(methyl methacrylate) powder + plasticizer+ adhesion promoter. Uses: metals (sheet-metal constructions), silicate-containing materials.