Study of wetting on the non-image area of offset printing plates by an alternative iso-propyl alcohol-free fountain solution

Abstract

In this study, an alternative aqueous isopropyl alcohol-free fountain solution for sheet-fed offset printing is prepared comprising 5 w/w% McIlvaine's buffer system for pH control, 0.3 w/w% Polysorbate 80 as a surfactant, 1 w/w% magnesium nitrate hexahydrate as a conductivity agent and 10 w/w% ethylene glycol mono-butyl ether as an additional wetting agent. The percentages of each composition are w/w% of active and then adjusted to 100 w/w% by adding distilled water. The contact angles of the obtained fountain solution on non-image areas of three common offset printing plates: CTP plate of Kodak, CTP plate of Huaguang Graphic Co. Ltd (China), and CTP plate of Mylan Printing Media Co. Ltd (Vietnam), range from 10° to 20°.The surface tension, conductivity, pH and viscosity were found to be 30.5 mN/m, 1.45 mS/cm, 4.8, and 1.05 x 10-2 g/cm.s, respectively. In comparison to the commercial fountain solution (KF - Trade Mark (China) containing isopropyl alcohol (IPA), the obtained fountain solution shows similar wettability on the non-image area of the offset printing plate whilst having similar physico-chemical parameters. The results indicate that ethylene glycol mono-butyl ether could be a potential substitute for IPA in fountain solution in offset printing, and the obtained fountain solution displays suitable properties for the offset printing process.