Лако-красочные материалы — производство

The surface condition ofthe adherents is one factor which has the greatest impact on the quality and durability of adhesively bonded joints. Therefore, both in the literature and in adhesive manufacturers data sheets it is strongly recommended that the adherent surfaces are cleaned and carefully prepared prior to bonding. Only in few cases where the […]

Many factors influence the load capacity of adhesive bonded joints [3-7]. In a first approach, simplified design rules may be used to estimate the average stress in basic joint layouts [3] (Figure 6.10). Figure 6.8 Avoiding peeling in bonded joints [1]. Favorable Not favorable u ________ і —- , * J О г * a […]

The design considerations for optimizing a bonded joint should mainly include: • avoiding peel forces • generating compressive stress rather than tensile stress • avoiding stress concentrations in the bond-line [1] The stress concentrations present at the ends of the overlapped joints are due to the difference in axial strain occurring in the adherents as […]

For the design of structural adhesive bonded joints, it is necessary to take the time-, deformation — and temperature-dependent behavior of the adhesive polymeric ma­terials into account. Modern finite element analysis methods and tools allow a prediction ofthe stress distribution and deformations to be expected in an adhesively bonded joint, provided that the relevant material […]

When designing adhesively bonded joints, one should be aware that many of the mechanical properties ofthe polymer in the bond-line are different from those ofmetal — lic and other inorganic materials. Indeed, its strength is relatively low, its deformation properties are nonlinear and time-dependent (viscoelastic-plastic behavior), and irreversible material damages may occur when exceeding a […]

Fillers are fine solid materials that are added to adhesives and are, at best, adhesively bound to the polymer. Generally, they have an inorganic nature, although organic material (e. g. rubber) is used in special cases. The importance offillers is also often underestimated, because they are believed to be used only to reduce the content […]

The existence ofadhesion promoters has long been known. For example, as far back as the eighteenth century, Henry Duhamel du Monceau (see Chapter 2) explained that the adherence of glue to wood could be improved by rubbing the wood with garlic before the glue was applied. Whilst this was mere speculative experience, reactive organosilanes [42, […]

The polymer chemistry of primers used in adhesive bonding technology is basically the same as the polymer chemistry of adhesives. A primer may simply be an adhesive solution that improves wetting and protects the surface in the dry or cured condition. Strictly speaking, the primer transforms the adherent surface into a polymer surface that, with […]

The effect of primers on manufacturing processes and adhesion, as well as their basic chemistry, was described in Section 4.4. It has also been mentioned that primers may contain adhesion promoters because it does not always make sense — even if it is possible — to directly add specific adhesion promoters to the adhesive. It […]

In recent years it has become apparent that natural material-based adhesives still have industrial importance. However, gene technology may make it possible to further develop these adhesive systems by skillfully influencing natural materials in such a way that advantage can be taken of adhesive systems already existing in nature. For example, barnacles are able to […]