An Explanation of Density Anomalies in Electrostatically Assisted Gravure Printing.

Electrostatically assisted gravure printing quality was investigated in relation to practical gravure inks, using a laboratory proofing press. Light was thrown on the problem of reflection density changes found when using publication type inks. Quantitative analysis by an X-ray emission technique was used to determine the changes in the printed ink film composition caused by the application of electrostatic assist. These results showed a definite change in the pigment/binder ratio with low conductivity inks (publication type) which indicated that electrophoresis was taking place. A two-stage mechanism is proposed for electrostatically assisted gravure ink transfer. These results showed a definite change in the pigment/binder ratio with low conductivity inks (publication type) which indicated that electrophoresis was taking place. A two-stage mechanism is proposed for electrostatically assisted gravure ink transfer.