Determining Printablility of Liner-Board Manufactured for Postprint Converters Using Water-Based Flexo-Graphic Ink, 1997 Process & Product Quality Conference Proceedings

Flexographic printing, using water-based inks on postprint presses, or direct print, has evolved rapidly in the past few years and the pace of change seems only to be increasing. The corrugated industry has gone from single-color “commercially acceptable” standards to multi-color, “we want it to look like lithography” standards. Recent changes in printing presses, printing plates, inks, and linerboard have all converged to allow converters to get closer to that “litho look”. Improvements on the direct print side of the business include 1) printing presses with chambered-blade inking systems to lay down thinner ink films and servo drives to improve registration accuracy, 2) anilox roll engraving and coatings, 3) printing plate materials, uniformity across plate, and plate mounting accuracy, and 4) ink formulations. The last remaining variable is the substrate. Have substrate manufacturers kept pace with these quantum leaps in equipment and process improvements by manufacturers of products which had also contributed to variability in the printing process? Substrates, too, have changed to accomodate evolving markets and higher end-user expectations. Brighter, cleaner, whiter, and smoother liners are now being manufactured. The next generation of graphics-oriented linerboards are concurrently being developed and tested at converting plants. Historical testing methods to determine a substrate’s quality and ability to print well included caliper uniformity, brightness, and roughness. Ability to convert downstream in the plant were partially determined by scuff testing and internal bond. Recently, a new test has been gaining acceptance as a reliable tool to predict printability - the EMVECO smoothness profiling system. We will examine the methodology and results of this predictive test method.