Details:
Summary:
With any type of printing, controlled and consistent ink conditions, such as temperature, viscosity and pH of water-based inks are essential to achieve a consistent print quality. The performance of water-based gravure spot color inks during the printing trials simulated on the laboratory scale, using a Moser sheetfed gravure proofing press, was investigated. The viscosity and pH profiles of water-based gravure inks were monitored. Changes in the rheological behavior of the tested inks after different dwelling time of inks on the press and changes in the flow properties were observed. Viscoelastic behavior of the tested inks showed that the strength of ink's structure is time-dependent. Color stability during the printing trials was tested in terms of reflective spectra; CIE Lab color coordinates and color difference. The importance of viscosity and pH control of water-based gravure inks was shown. It was observed that even if the ink's pH drop is in the acceptable range for water-based inks, keeping it constant during the printing runs improves the color stability.