Quality of Digitally Printed Paperboard for Folding Cartons

The global market for digitally printed packaging grows rapidly. This study focused on using dry and liquid toner system to print on regular paperboards, which are originally for lithographic or flexographic printing. Uncoated, gloss coated, and cast coated paperboards with different calipers were tested. The paperboards were printed with and without surface treatment to modify paperboard surface energy. The printed paperboards were folded with and without scoring. The folding occurred at printed areas including single color and multiple color overprints. To study the contribution of varnish to folding quality of paperboard, printed paperboards were applied aqueous coating. The folding quality was evaluated under microscope and calculated by density variation. The results showed that folding cracked the inkfilm printed with dry and liquid toner. Coated paper had less folding cracks than uncoated paper. With increasing paper caliper, the folding got worse. Scoring improved folding quality.