A Corona Study Relevant to Electrostatic Printing Process.

An electrostatic printing method is used to make multicolor reproductions of topographic maps. An area of interest of the process is the possible action of the double corona charging units in the machine on the chemistry of the materials that pass through the corona discharges during the printing sequence. The study will show what effects are observable on representative examples of the dye sensitizer, toner, binder, dispersant, and electrophotographic paper used in the process when these materials are exposed under assimilated printer conditions. Four compounds were observed under conditions which simulated the corona unit. It was found that the only compound formed via the discharge was that of ozone O3. Phthalocyanine blue, Isopar G, Fluorescein, and an alkyd resin were subjected to ozone concentrations. Other studies including paper charging rates as a function of atmosphere, toner, sedimentation rates, and the effect of ozone on the electrophotographic paper have been carried out. Author