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Liquid painting

Applications

The charged, very fine atomized paint drops are attracted to the grounded workpiece with electrostatics. Even paint droplets that would normally fly by the workpiece now follow the field lines and land on the workpiece.

With electrostatics the application efficiency reaches up to 95%.

Liquid painting without electrostatics

During painting electrostatics is primarily used for increasing the TE (transfer efficiency). The objective is to get as much paint as possible onto the workpiece during atomization. Often with painting without electrostatics only 30% of the sprayed paint reaches the workpiece and 70% is caught in the exhaust and the downstream filter.

Liquid painting without electrostatics

Liquid painting with electrostatics through contact charging

As a rule during electrostatic wet painting the paint is set on high-voltage potential. The amount of voltage varies in this depending on the application, paint and geometry of the workpiece. Normal voltages during electrostatic wet painting lie between 50,000 and 100,000 volts. The paint is either charged through contact with the high-voltage or by ionization in flight. During contact charging the atomizer is set to high-voltage potential using the high-voltage generator and the paint is charged by this during atomization.

Liquid painting with electrostatics through contact charging

Liquid painting with electrostatics through external charging

During external charging the paint droplets are charged in flight through ionization. This is especially found in the use of conductive paints, e.g. water-based paint application. A conductive paint would cause a short-circuit to ground during classical

Liquid painting with electrostatics through external charging