The importance of surface pretreatments in prior to bonding

An explanation of the adhesional mechanisms is only possible by high resolution analytical techniques. Adhesion is not, as is simply assumed in most of the theories, a two-dimensional phenomenon in which two materials, i.e. adhesive and metal, are observed as not being influenced by each other. In fact the boundary layer is a three-dimensional, multimaterial problem and one has to understand that the adhesion partners influence each other and can change not only during commencement of adhesion but also during ageing processes. Thus, from further investigations, more detailed analytical results will have to be obtained concerning the material conditions at different regions of this boundary layer zone. It is however already possible nowadays in the present state of knowledge, at least in the system aluminium-polymer, to carry out certain systematical optimization. For example, the chemistry of adhesives taking into consideration the durability of the boundary layers will have to altered , or surface pretreatment methods will have to be developed which allow for durable adhesive substrates on metals. A start for a systematical optimization in this direction has thus already been made.