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Electrostatic powder spraying (EPS)

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Electrostatic powder spraying (EPS)

In this coating process, powder granules are electrostatically charged during spraying with air and attracted to the earthed component as a powder cloud. The powder layer melts when the component is heated and forms a closed coating after cooling.

EPS is a very environmentally friendly and economical coating process. Different types of powder coatings can be used to coat different substrate materials and meet different requirements.

 

The powder coating particles can be charged in two ways:

  • Corona charging
  • Tribocharging

 

In the corona spray system, the powder particles are charged negatively - either inside a spray gun or in an applied high-voltage field when the powder emerges. The ionised powder particles then travel along the field lines to the positively charged, grounded work-piece. If a high working speed and the coating of large surfaces are required, this process is the obvious choice. During tribo-charging (friction charging), the powder coating passes through a PTFE tube at high speed. Under air turbulence, all particles rub against the surface of the tube, give off electrons and are positively charged. Work-pieces with recesses and cavities in particular benefit from this process.

An essential component of the electrostatic powder spraying system technology is the powder coating booth. In addition to defined air guidance and extraction, it also contains control and safety systems as well as a powder recovery system.

Thermoset powder coatings are used, which melt and cross-link on the hot component surface.