What is defined as the surface of an adherend?

The surface of an adherend refers specifically to the solid material that is being bonded in an adhesive application. This material, known as the substrate, is crucial because it provides the physical foundation for adhesive bonding. The characteristics of the substrate, such as its texture, cleanliness, and chemical composition, significantly affect the adhesion process and the overall performance of the bonded joint.

The adhesive layer is the material that is applied between two adherends, and while it is important for creating the bond, it does not describe the surface itself. The bond interface is the region where the adhesive meets the adherend surface, but it does not cover the entirety of the adherend itself. The curing area relates to the conditions under which a curing adhesive sets but does not define the adherend. Thus, the term “substrate” is the most accurate choice to describe the surface of an adherend in this context.