Лако-красочные материалы — производство

For moderately rough surfaces, an increase in surface area may well lead to a proportionate increase in adhesion, so long as the roughness does not reduce contact between the surfaces. Gent and Lai have convincingly demonstrated the effect in careful experiments with rubber adhesion [65]. In comparing adhesion to smooth and to grit blasted steel, […]

Having discussed the nature of surfaces and of surface roughness we now move on to examine some recently published work, selected to illustrate different ways in which inter­facial roughness may affect the strength of an adhesive joint. Interfacial roughness of potential significance in adhesion may be on a scale ranging from the macroscopic to the […]

It may not be possible, even in principle, to ascribe a unique ‘‘surface area’’ to a surface. It has long been recognized from work on gas adsorption on porous solids that the surface area measured depends on the size of the probe molecule. A small probe can enter finer surface features and therefore may give […]

Can the simple roughness factor approach (Eq. (8) be applied if the surface is very much rougher? Many of the surfaces encountered in adhesion technology are very rough indeed. Figure 1 shows a microfibrous oxide on steel and a porous oxide layer on aluminum. Figure 4(a) shows a phosphated steel surface prepared for rubber bonding […]

We have seen how the concept of surface energy in principle relates to adhesion. The surface energy terms discussed (e. g., Eqs. (1) to (7)) are all energies per unit area. We now need to consider carefully what we mean by the interfacial area. If the interface between phases 1 and 2 is ‘‘perfectly’’ flat, […]

It may be adequate in everyday life to think of a flat surface as the two-dimensional plane of Euclidean geometry. This, like the perfectly straight line with length but no breadth, is a Figure 2 Fully hydrated calcite {1011} surface showing (top) rotation of surface carbonate groups with (bottom) bulk ordering below the surface (after […]

Most historical surveys treat the work of McBain and Hopkins in 1925 as the earliest application of modern scientific investigation to the study of adhesion [9]. McBain and Hopkins considered that there were two kinds of adhesion, specific and mechanical. Specific adhesion involved interaction between the surface and the adhesive: this might be ‘‘chemical or […]

The sensation of stickiness is among the commonplace experiences of humanity. Resin oozing from a pine branch and the sap from a dandelion stem are among a multitude of natural examples from which it can be asserted with confidence that humans have ‘‘always’’ been aware of the phenomenon of adhesion. Indeed for millennia, as a […]

D. E. Packham Center for Materials Research, University of Bath, Bath, England

Adhesion is a very complex field beyond the reach of any single model or theory. Given the number of phenomena involved in adhesion, the variety of materials to be bonded, and the diversity of bonding conditions, the search for a unique, universal theory capable of explaining all the experimental facts is useless. In practice, several […]