The new possibilities with personalized and on-demand printing are strongly dependent on successful finishing. Today, however, the finishing is often seen as the week link in digital printing. The area is in great need of improvements to attain higher quality and cost effectiveness. A research study, based on a market analysis, was performed in close co-operation with the graphical industry. The study includes tests of different folding techniques and its function in a Print-on-Demand production process. The objective is to analyze the printed papers fold quality and functionality in the finishing process.Three different digital printing units, using the xerographic technique, were tested. Uncoated and coated paper qualities of stock weights above and below 150g/m2, developed for digital printing, were used in the study. The folding tests were performed 1-2 hours after printing. A single fold was applied to each printed test image, using two different folding machines and several folding strategies. The tests were performed in a climate–controlled laboratory, where the settings 20°C and 30%, 50% and 70%RH were used.Results show substantial differences between different folding techniques. The use of creasing was of vital importance in all cases. The results also indicate a diverse function of the tested digital printing units, most probably explained by dehydration of the papers in the printing process.
Johan Eklund, Bertil Österberg, Lars Eriksson, Lars Eidenvall, "Finishing of Digital Prints – A Failure Mapping" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP18), 2002, pp 712 - 715, https://doi.org/10.2352/ISSN.2169-4451.2002.18.1.art00069_2