Friction Charging (Tribostatic Charging) for powder coating

Friction Charging (Tribostatic Charging) which generates an electrostatic charge on the powder as it rubs against an insulator

Powder particles are friction charged as a result of the motion caused by each particle rubbing rapidly against a special type of insulating material which lines the barrel of the spray gun.

Between the friction charging spray gun and the object, as the diagram illustrates, we have present primarily:

With friction charging, there exists no high voltage which can subsequently generate free ions or produce electric fields.

Efficient friction charging of powder particles depends on each particle being rubbed against the barrel of the spray gun. This, as a rule, can be adjusted by regulating the air flow through the gun as well as the powder/air ratio for optimum performance.

Most friction spraying devices are equipped with a microamperemeter that provides an indirect measure of the powder charging process. This electrical current measurement, however, depends on the amount of powder passing through the spray gun. A high mA reading does not guarantee good coating results. The most important factor is maximizing the proportion of charged powder particles existing the spray gun.