Powder coatings surface quality

Direction of innovation tfrom the standpoint of market actors - 6al Automotive manufacturers substantiate the reduction of solvent emissions by water-based and powdered coatings on the basis of emission statistics. However, the automotive manufacturers state the improvement of the surface quality with the simultaneous improved cost-effectiveness of procedures as the decisive criterion for successful innovation. 

Powder paints are commonly applied by electrostatic spraying on metal substrates. The powder particles are charged inside the spray gun (Corona or Tribo) and adhere to the earthed metal object. Powder coating is ideal for coating complicated three-dimensional objects because the powder particles can easily reach recessed surfaces or even the backside of surfaces, following the electrical field lines from the gun to the substrate. Powder paint which does not reach the object or disassociates from the surface ( overspray ) can easily be gathered, recycled, and re-used without loss of quality (Figure 16.6). The substrate, covered with a layer of powder paint, is subsequently heated in a hot-air oven. The powder particles melt, coalesce, and fiow out into a film. 

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