During the creation of an adhesive bonded joint, all types of adhesive must undergo transition from the liquid to the solid state, except for pressure-sensitive adhesives (PSAs), which comprise both liquid and solid properties and thus have a permanent tack and adhesive bonding ability. Viscosity is a prerequisite of the adhesive to bring it and the adherent into close proximity, and to allow adhesive forces to originate. The material properties that prevail after curing are responsible for the cohesive strength of the bonded joint.
Curing may take place according to a wide variety of chemical and physical mechanisms, all of which have been translated into adhesive systems with advantages and disadvantages for the manufacture process, depending on the materials to be joined and the structure of the paramount process chains (see Chapter 4).
Some combinations of application forms and processing/curing conditions of physically setting and reactive adhesive systems are summarized in Tables 6.1 and 6.2.
Specific examples will be discussed in the following sections in order to illustrate the possibilities and processing parameters available today.