The quality of surface treatment is often the key to obtaining a good adhesive joint, because the permeability of the adhesive into the surface of the adherend and the intermolecular forces (i.e., adhesion) at the interface are the main reasons for achieving high bonding strength. During manufacturing, transportation, storage, and use, the surface can be contaminated to varying degrees, directly affecting the penetration of the adhesive and the bonding strength. The importance of surface treatment is as follows.

① When preparing building parts before bonding, there are often oil stains, mold release agents, weathered layers, carbonized layers, and corroded layers. If these unclean and weak surface layers are not removed, they will greatly affect the bonding performance.

② Roughening the surface of the adherend can increase the actual bonding area of the adherend. For example, sandblasting can increase the bonding area of a polished metal surface by 20 times. In addition, a rough surface allows the cured adhesive to form more interlocking structures with the adherend, that is, mechanical interlocking, thereby improving bonding strength. This has been confirmed by both theory and practical experience.

③ Surface treatment can also improve surface properties. For example, chemical treatment of metal surfaces can provide a higher surface tension on the adhesive surface, thereby improving bonding strength. Some difficult-to-bond low-energy surface composites and rubbers can only be effectively bonded through surface treatment (such as treating PTFE with sodium naphthalene solution). The aforementioned coupling agents can also improve the bonding performance of surface treatment. Therefore, surface treatment is very important in the building bonding process.