Static Electricity in Printing.

The elements of static electricity are reviewed briefly, and the mechanisms of static generation and methods of static elimination are explained. It is shown that static charges on paper can be generated in two ways; (1) by contact electrification, and (2) by induction. Elimination of static in paper can be accomplished only if electrical conductivity is established, either in the paper or in the air near the paper. Air is an insulator and must be ionized to become electrically conductive. Paper is an insulator when dry, but can be made conductive by absorbing moisture, such as by storage in a humid room. The role of relative humidity in static elimination, and the various methods of eliminating static by the ionization of air are discussed.