Devising a Procedure for Examining the Quality of Prints of Digital and Offset Printing on Corrugated Cardboard

Abstract

The rapid development of digital printing and the popularity of corrugated packaging production encourages manufacturers to improve product quality. Therefore, research into the quality of digital prints, using modern procedures for determining the qualimetric indicators, is important for both consumers and manufacturers. We have studied the prints made by the inkjet printing machine Durst Rho 1312. The printing involved the inks CMYK+Light Cyan+Light Magenta (Austria)+Light Cyan+Light Magenta. The prints were obtained directly on five-layer corrugated cardboard using the post-print technology. In addition, the printing was performed on a liner, followed by its pinning to fluting (the preprint technology). The paper describes a procedure for determining the qualimetric prints’ indicators, in particular, optical density, the increase in the tonality of the raster image, color reproduction, resolution, print stability on prints, and in the printing process, and lightfastness. The imprints’ quality was evaluated in accordance with the requirements set by the standard ISO/TS15311-2:2018. The quality of digital and offset prints has been compared. It has been established that the digital post-print technology on the five-layer corrugated cardboard BE and the pre-print technology on the cardboard GD180 ensure the same print quality parameters. This includes such a quality indicator as the reproduction of raster image tones, optical density, color difference, printing stability. The print resolution of the imprints has slight deviations. It was found that the color transfer of offset prints is higher (by 10 %) than that of the digital prints based on the pre-print technology. Offset printing also provides higher resolution (by 93 lines/cm) than digital printing. However, in terms of print stability and color difference, the inkjet prints are inferior to the offset technology. Digital prints have good lightfastness (10‒20 times better than offset samples)