抄録
Both calcium carbonate and talc powders dried in a desiccator for about a day were used as the model of spraying materials which have been applying widely on printed sheets delived from a sheet-fed press. The electrostatic charges generated by rubbing the powders against a surface of glassine paper or aluminium plate were measured by use of a electrometer.
As the results, it was obtained that the calcium carbonate powder has the positive charge through rubbing against a surface of glassine paper or aluminium plate, while the talc powder appears constantly negative in charge in the same conditions. Further, it was observed that the negative charge on talc powder is decayed considerably by passing the powder through a ring electrode having the possive potential.
