Electrostatic Spraying of Liquid Insulators

A method for generating drops of liquid insulators using electrostatic spraying is reported. This method differs from normal electrostatic spraying in the method of charging the liquid. A sharp needle placed in the liquid near the end of a capillary is raised to a high potential, thus injecting charge into the liquid. As the voltage is raised, a jet is formed electrostatically with the size of the jet decreasing with increasing voltage. A theoretical prediction of the jet radius as a function of current is obtained by finding the amount of electrical energy which goes into mechanical energy. Experimental results of the spraying of silicone oils are given and compared with the theory.