4 октября, 2015 
Pokraskin Grit blasting is carried out by aiming abrasive materials (e. g. corundum) by means of a jet of air onto the surface to be treated. The degree of abrasive surface removal and deformation caused by the particle impact is determined by the form and hardness of the blast medium, the applied pressure, and the distance of the blast nozzle from the surface. When the blast medium impacts the surface, very high, localized energy concentrations are created. Thus, it is assumed that during a short duration, a plasma state is created in the impact area. When the plasma collapses, condensed residues may recontaminate the adherent surface. Hence,
the material properties of the blast medium may influence the adhesion properties of the blasted surface (see Sections 7.4 and 7.5). The two blast systems generally used are:
• dry blast processes, such as flywheel-blasting, grit-blasting and vacuum-blasting
• blast processes using fluids, such as water-jet blasting, hot-water and steam blasting
The blast media comprise metallic, organic and mineral materials. It is important that the blast medium (e. g. compressed air) is free from contaminants such as oil and silicone. In the case of plated substrate materials, the plating may be damaged and a mechanical deformation of sensitive materials may occur under the influence of compressive internal stresses at the superficial areas zone.
In the special blasting method known as SACO (SAndblasting and COating), corundum coated with reactive silicate is used as the blast medium. When the grit hits the surface and the plasma collapses, part of the silicate coating is assumed to transfer to the adherent. In a next step, a silane adhesion promoter is applied to the silicate-containing layer (see Section 5.10) to yield a surface with good adhesive properties. Precautions must be taken when using this process, however, as harmful silicate dust may be produced.
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