A new methodology for the use of a printability tester for the simulation of flexographic halftone printing onto film substrates

An experimental investigation has been performed to optimise a methodology for obtaining halftone test prints using a printability tester. A test image containing two gradation scales was printed onto a film substrate using UV cured ink. Initial problems due to poor ink transfer from the plate to the substrate were overcome by modifying the configuration of the printability tester was modified to increase the tension in the substrate. Neither the anilox nor the plate was cleaned between printed samples. Spectrophotometry measurements of the printed samples showed a significant increase in density occurred between the first print and subsequent prints, as the ink transfer from the plate, which occurred after approximately 6 prints. The stabilised density and halftone reproduction of the prints were similar to those produced on a commercial printing press under the same nominal conditions, showing that this method is suitable as an alternative to full-scale press trials.