Towards the optimisation of the flexographic printing of corrugated boards for quality improvement

摘要

With the technical support of a group of partner companies, we have undertaken an experimental study of the quadrichromic printing of various corrugated boards by a flexographic post-printing process. A set of parameters were chosen and varied to highlight their influence on the resulting quality of the prints by means of an original test form : 1. top paper grade, 2. flute geometry, 3. printing plates thickness and underlying foam substrates, 4. ink sequence and parameters (viscosity, pH), 5. physicochemical surface characteristics. Three kinds of quality criteria were evaluated: 1. solid density (mean value and evenness) and colour gamut, 2. dot gain, 3. ink trapping. In this last case, we used classical indexes (through Preucil and Ritz formulae) in association with image analysis. The results were handled by a systematic approach comprising 53 combinations of parameters. Their analysis led to the possibility of finding an optimal set of parameters yielding the best print in terms of both aesthetic and technical performance by reference to a high quality printing process.