How the ESS MaxCharge™
Spray Nozzle Works

The heart of the ESS sprayer system is the Max-Charge induction electrostatic nozzle. The original induction charging air-assisted nozzle was invented by
Dr. Ed Law at the University of Georgia. ESS has made many improvements to
Dr. Law's original concept; the result is a simple, safe, and reliable electrostatic spray nozzle system.

Air and liquid enter separately at the rear of the nozzle. The air moves at near-sonic speed through the nozzle and impacts the liquid at the tip. This causes the formation of optimum-size spray droplets of 30 to 40 microns in diameter. The air pressure needed is only 20 to 90 psi. At these low pressures the nozzles last a long time. As the spray is atomized the liquid passes an electrode inside of the nozzle. Electrons are induced onto the liquid stream and the droplets leave the nozzle with a high negative charge. The droplets are carried in an air stream towards the target surface. The closer the charged droplets get to the target, the stronger the electrostatic forces of attraction. The droplets follow electrical field lines of force and wrap around the target. Once droplets hit the target they immediately lose the electrical charge. The induction charging used in ESS's MaxCharge nozzle can produce a very high charge without using high voltages. Other types of charging methods, such as contact charging, use voltages that are much too high to be safe or reliable. The MaxCharge nozzle is easily disassembled for cleaning.

The Science behind Electrostatic Spraying

Coulomb's Law says that opposites attract, or more specifically, unlike electrical charges attract to each other. Because of Coulombic forces, when charged spray particles are near any object with an opposite charge, they will be attracted to that object. They will follow electrical field lines and wrap around and coat all sides.

ESS takes advantage of this physical principle to allow spray applicators to do a better job and to help provide less environmental impact. In addition ESS uses air-assistance to help with spray delivery. Air is necessary in electrostatic spraying to cause the charged spray to push deep into complex targets, such as hospital rooms or subway cars.

To fully take advantage of the force of electrostatic attraction we need to make the droplets very tiny - about 40 microns. When the droplets are small enough and the droplet charge is sufficiently high, the droplets have a force of attraction of 75 times greater than that of gravity. The result is the droplets can reverse direction and move upwards or around objects to coat hidden surfaces.

Electrostatics, with air-assist, plus the right droplet size is a good combination for the best possible spray job.