When preparing a surface for coating it is important – apart form cleanness – to get a structure of the surface that offers optimal adhesion of the coating. This adhesion is ensured by obtaining a suitable degree of roughness and structural shape.
In case of high roughness heights the consumption of paint is higher than for lower roughness heights. It should also be taken into account that the applied coating thickness of the paint should correspond to the obtained roughness height.
Roughness and structural shape depend on:
the abrasive:
- shape of the grain
- composition of the operational mixture
- hardness of the abrasive
- toughness of the abrasive
the blasting unit:
- nozzle (shape of the nozzle)
- pressure – discharging speed
the material to be blasted:
- hardness
- intensity of the jet
the blasting device:
- impact angle
- distance between workpiece – nozzle
- nozzle movement and guidance.
Example: Different abrasive grains (steel shot)
Ra = medium roughness value
Rmax = maximum roughness height
Rz = averaged roughness height
- Table of contents
- 1. Fields of application of abrasive blasting technology
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2. Blasting technology
- 2.1 Airless blast cleaning
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2.2 Injection blasting
- 2.2.1 Compressed air blasting (also air blast cleaning or sand blasting)
- 2.2.2 Pressure blasting (injector blasting)
- 2.2.3 Vacuum-compressed-air blasting and vacuum injection blasting
- 2.2.4 Damp blasting
- 2.2.5 Wet blasting
- 2.2.6 Slurry blasting
- 2.2.7 Ice Blasting
- 2.2.8 Water- jetting cleaning and hydro-jetting
- 2.2.9 Wet blasting for fine surface treatment
- 2.2.10 Combination of different blasting methods
- 2.3 Laser cleaning
- 3. Abrasive
- 4. Efficiency assessment of abrasive blasting
- 5. Influence of compressed-air blasting on the surface of the workpiece
- 6. Generation of compressed air
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7. Plants for compressed-air blasting
- 7.1 Small and medium-sized blasting pots
- 7.2 Large blasting pots
- 7.3 Double-chamber blasting pot
- 7.4 Mixing and dosing valve
- 7.5 Hoses, lengths of hoses, couplings
- 7.6 Selection of a blasting pot in considering the wear and tear behaviour
- 7.7 Increased wear and tear at the blasting pot caused by wrong adjustment
- 8. Remote control and emergency shut-downs
- 9. Jet nozzles
- 10. Stationary blasting halls
- 11. Mobile abrasive blasting equipment
- 12. Laws and provisions