August 2025

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Daniel Bohn

The news section of the Journal: Topicalities

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A novel methodology for assessing the latency of water-based inkjet inks

Amélie Brogly¹, Aurore Denneulin¹, Raphaël Wenger ², Gilbert Gugler ², Gioele Balestra ² and Anne Blayo¹

E-mails: amelie.brogly@grenoble-inp.fr, aurore.denneulin@grenoble-inp.fr, raphael.wenger@hefr.ch, gioele.balestra@hefr.ch, anne.blayo@grenoble-inp.fr

(1) Université Grenoble Alpes, CNRS, Grenoble INP, LGP2, F-38000 Grenoble, France
(2) iPrint Center, HEIA-FR, HES-SO, University of Applied Sciences and Arts Western Switzerland, 1700 Fribourg, Switzerland

Abstract

The use of digital printing in the printing industry continues to expand and evolve, largely due to the versatility of inkjet technology, which offers extensive possibilities in terms of customisation and a wide range of applications compared to conventional printing techniques. Moreover, growing environmental awareness drives the development of water-based inks. However, the use of aqueous inkjet inks requires considerable expertise in the drop-on-demand ejection process. Indeed, a common issue with inks of this nature is the generation of defects in printed designs, such as missing areas and lines, often caused by nozzle latency. The latency phenomenon occurs when nozzles fail to fire drops after a period of inactivity (idle time). This paper presents two innovative quantitative methods to assess the latency phenomenon of water-based inkjet inks: one involving direct observation of printed results thanks to a specific test form, and another focusing on the observation and analysis of the drop ejection. These techniques can help ensure a reliable ink ejection in an industrial production context.

Keywords: digital printing, water-based inks, latency, idle time, drop

JPMTR-2506 Original scientific paper | 198
DOI 10.14622/JPMTR-2506
UDC 655.3:667.6

Received: 2025-05-22
Accepted: 2025-06-20

Predicting the jetting performance of an ink and issues associated with translating a printable ink in the lab to large-scale industrial manufacturing

Alyssa A. Wroniak, Yen-Hsun Huang and Patrick J. Smith

Emails: aawroniak1@sheffield.ac.uk, yhuang130@sheffield.ac.uk, patrick.smith@sheffield.ac.uk

University of Sheffield,Laboratory of Applied Inkjet Printing, Department of Mechanical Engineering
64 Garden Street, Sheffield, S1 4BA, England United Kingdom

Abstract

Inkjet technology is advancing to allow for more printable materials (e.g. higher viscosity inks can now be jetted). However, there is an issue of materials that can be printed in the research lab becoming unprintable when scaled up to the industrial scale. In this review, the differences between inkjet printers that are used in academic research and those that are used in industry are discussed. In academia, there is a focus on exploring new applications where inkjet can provide an advantage, which requires the use of simple inks (e.g. a solvent). In industry, the focus is on productivity, which results in inks containing a range of additives that ensure regular, reliable printing over long cycle times. Therefore, the principal question is, how does one gain confidence in an ink’s printability regardless of the printer or scale of work employed? Inkjet research uses small-scale printers whereas industry uses large-scale printers. The scale of work leads to printing conditions specific to the machine used that can change the printability of an ink (as it translates from academia to industry). This difference in printing conditions is creating a gap between academic inkjet research and industrial inkjet development. To understand how to traverse this gap, all the factors that affect the printability of an ink need to be evaluated and understood. Printability is determined by fluid properties, rheology, and printing conditions. Thus, this review investigates printability. By understanding all the factors that affect printability, and how research-lab inkjet and industrial inkjet differ, an improvement in the transfer of newly researched inkjet systems into the industrial markets can be achieved.

Keywords: Ink formulation, inkjet printability, rheology, additive manufacturing, jet-ability performance

JPMTR-2505 Review paper | 199
DOI 10.14622/JPMTR-2505
UDC 655.3:667.6

Received: 2025-02-28
Accepted: 2025-08-02

The effect of offset printing plate deformation on print quality

Gülhan A. Büyükpehlivanoğlu¹, Mehmet Oktav², Lutfi Özdemir¹, Elif Ural¹ and Pelin Hayta

Emails: gulacar@marmara.edu.tr, moktav@marmara. edu.tr, lozdemir@marmara.edu.tr, eozenural@marmara.edu.tr, phayta@sinop.edu.tr

(1) Marmara University, Vocational School of Technical Sciences, Audiovisual Techniques and Media Productions, Istanbul
(2) Marmara University, Faculty of Applied Sciences, Printing Technologies Department, Istanbul eozenural@marmara.edu.tr
(3) Sinop University, Gerze Vocational School, Department of Graphic Design, Sinop.

Abstract

To be able to make quality prints on uncoated paper, it directly depends on the printing system, the physical properties of the substrate, the ink and ink drying method, the plate properties and the number of prints, the printing room conditions, and the properties of other main and auxiliary materials used in printing. Web offset printing system (heat-set), uncoated paper, CtP plate preparation, heat-set inks, and drying methods were considered in this paper. For prints made on uncoated papers, the loss of quality caused by the wear of the printing plate due to physical and chemical effects during the printing process was examined practically by test printings. For this purpose, 180 000 test prints were made with thermal CtP plates used in heat-set printing. Microscopic and three-dimensional/topographic images of the surface were taken before and after printing, and their areas at the level of micrometer square (µm2) were measured. Dot size deformation was also visually examined and evaluated, depending on the number. For high volume print run on uncoated paper, it was determined that the plate must be replaced per 150 000 impressions or baked before printing.

Keywords: web-offset printing, computer to plate, offset plate deformation, print quality.

JPMTR-2503 Original scientific paper | 200
DOI 10.14622/JPMTR-2503
UDC UDC 655.344: -035.57

Received: 2025-01-29
Accepted: 2025-08-06