September 2016


Gorazd Golob






A model of sustainable production: ecological and economic benefits of high-gloss UV-coating in offset printing without a relevant loss in gloss quality

Kirsten Radermacher
Erbschloeer Strasse 22, D-42369 Wuppertal, Germany


This paper presents a guideline for enterprises to realize sustainable production in compliance to economic interests. A special perspective on the product quality that is perceptually noticeable, or required for customer satisfaction, enables to reach economic benefits not conflicting in respect with the principles of sustainability. Therefore, the model of sustainable production was exemplarily demonstrated by the glossiness of cardboard packaging. The investigation was mainly concentrated on the gloss measurement and perception aiming to define a threshold of perceptual gloss that gives information about the product quality required. Gloss has been a part of research work for decades. However, there are no researchers known who were able to quantify a threshold that inform about noticeable gloss differences. Furthermore, the measurement technology of gloss is much more complex than expected. The specular gloss is still the main important feature, and is broadly the essential measure in practical application. However, further gloss types are implemented in so-called goniophotometric instruments. In this paper, the currently available knowledge in gloss perception and measurement is used to generate a measure of perceptible gloss differences. Influencing factors affecting the environmental performance of high-gloss cardboard packages are presented, and suitable methods for measurement are employed. For high-gloss coated cardboard packaging, the volume of the coating roller and the intensity of the UV-curing unit reveal potential for sustainable production under consideration of the threshold of 2.0 Gloss Units that is recommended from a visual test performed. Considering the assumption made for the product example, 0.99 ± 0.65 g ∙ m−2 of UV-coating and 6.6 ± 3.8 kWh of energy could be saved. The integration of these scenarios in life cycle assessment (LCA) on coatings will help to assume whether these savings are crucial in the whole product life cycle. This paper gives first impressions.

Keywords: gloss measurement, gloss perception, ecological assessment, cardboard packaging, quality assessment

JPMTR 084 | 1609 Original scientific paper
DOI 10.14622/JPMTR-1609
UDC 655.1 | 338.3-035.67-022.316

Received: 2016-06-04
Accepted: 2016-09-07

Improving run-time stability with aerosol jet printing using a solvent add-back bubbler

Arjun Wadhwa1, Denis Cormier2, Scott Williams3
1 Quest Integrated, LLC, 19823 58th Pl. South, Suite 200, Kent, WA 98032 (USA)
2 Industrial and System Engineering, Rochester Institute of Technology, 81 Lomb Memorial Drive, Rochester, NY 14623 (USA)
3 School of Chemistry and Materials Science, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623 (USA)


Aerosol jet printing is a non-contact process capable of printing on conformal and flexible surfaces. Aqueous or solvent nano-inks are pneumatically atomized under nitrogen. The atomizing gas flow through the atomization cup leads to evaporation and removal of volatile solvent(s). As the ink solid loading fraction increases with the loss of solvent during atomization, the rheological changes eventually lead to instabilities in print output. A potential solution to this problem is to moisten the incoming atomizing gas with a solvent add-back system. In this study, neat co-solvent solutions of ethanol and ethylene glycol at 85 : 15 and 30 : 70 mixing ratios were atomized using nitrogen flow rates ranging from 600 to 1000 cm3 ∙ min−1 (ccm, cubic centimeters per minute). It was observed that ethanol, being the more volatile solvent, was depleted from the neat solution at a much higher rate than ethylene glycol. When nitrogen gas was passed through a bubbler prior to atomization, an excessive amount of ethanol was returned to the neat solution. The solvent loss rate from an ethanol rich neat solution (80 %) was higher compared to an ethylene glycol rich neat solution. Perfecting the solvent add-back rate to an ink will enable longer print runs in a manufacturing environment.

Keywords: aerosol jet printing, direct write, ink stability, solvent evaporation rate

JPMTR 085 | 1610 Research paper
DOI 10.14622/JPMTR-1610
UDC 655.1 | 62-1/-9

Received: 2016-06-05
Accepted: 2016-09-10

A method to compensate fluorescence induced white point differences in proof-processes by printing liquid fluorescent brightening agents using inkjet

Daniel Bohn1, Michael Dattner2, Stefan Fehmer3, Peter Urban1
1 University of Wuppertal, Faculty for Electrical Engineering, Information Technology and Media Technology, 42119 Wuppertal, Germany
2 BST eltromat Int. GmbH, Heidsieker Heide 53, 33739 Bielefeld, Germany
3 Laudert GmbH & Co. KG, Von-Braun-Straße 8, 48691 Vreden, Germany


One of the key goals in producing paper and cardboard in the print industry is to achieve a high whiteness degree. This is usually realized by fluorophores called OBAs (Optical Brightening Agents) or FBAs (Fluorescent Brightening Agents). The heavy use of FBAs in production substrates, while proof substrates contain a varying amount of FBAs, results into serious difficulties in any color management process, especially in terms of a white point correction.

In this study, an alternative procedure is presented to achieve an illumination independent colorimetric correlation and a visual match between most proof- and production substrates. This is achieved by printing defined amounts of liquid FBA using inkjet with variable area coverage.

Keywords: OBA, color management, FBA compensation, OBA compensation, carrier

JPMTR 086 | 1605 Research paper
DOI 10.14622/JPMTR-1605
UDC 655.1 = 774.8 (535.37)

Received: 2016-02-27
Accepted: 2016-05-24

Does the use of black ink still comprise the “darkest” issue of CMYK printing?

Yuri Kuznetsov and Maria Ermoshina
St. Petersburg State University of Industrial Technology and Design, North-West Institute of Printing, NWIP, Jumbula Lane 13, Saint Petersburg, 191180, Russia


Black ink can be used for multicolor printing to different extent within each of such multiple purposes, as: replacement of the achromatic component of three chromatic inks combination; reproduction of the image achromatic colors; expanding the color gamut; providing print security features… The relationships and effects within these functions are discussed in the paper on the background of prepress facilities evolution starting from the times of photoengraving and analogue scanners of 60’s up to the precise digital color control of today. The results of comparative colorimetric analysis of the sets comprising cyan, magenta and yellow (CMY), and cyan, magenta, yellow and black (CMYK) revealing the black in particular effect of expanding the print gamut by providing the darker chromatic colors which aren’t available for any combination of the other three process ones are also presented.

Keywords: color gamut, achromatic component, chromatic color, UCR, GCR, UC

JPMTR 087 | 1511 Case study
DOI 10.14622/JPMTR-1511
UDC 655.1 (774.8)

Received: 2015-12-14
Accepted: 2016-09-09

Evaluation of in-line viscosity measurement sensors in gravure printing

Henrik Knauber, Peter Schöffler, Thomas Sprinzing, Armin Weichmann
Hochschule der Medien, Institut für Angewandte Forschung (IAF), Nobelstr. 10, 70569 Stuttgart, Germany


For the stabilisation of printing quality, gravure printing machines are normally equipped with viscosity measurement systems. Recently two newly developed viscosity measuring systems, a microelectromechanical tuning fork sensor and an acoustic wave sensor, were introduced to the market. Those systems compete with the traditional rotary viscometer and the dropping body measurement. A system comparison of the different systems were implemented and performed at a Rotomec MW 60 rotogravure press. The aim was to find a system for in-line viscosity measuring of printing inks, which is as accurately as possible and does need minimal cleaning effort. Four experiments were conducted to evaluate the different viscosity measuring instruments: accuracy of the solvent concentration measurement, equipment capability, temperature behaviour in ink and influencing factors of viscosity measurement in the printing process. The results show that the acoustic wave sensor and the rotary viscometer are suitable for the viscosity measurement in gravure printing.

Keywords: viscosity sensors, tuning fork sensor, acoustic wave sensor, rotary viscosimeter

JPMTR 1510 Professional communication
DOI 10.14622/JPMTR-1510
UDC (655.1) 762 | 62-1/9

Received: 2015-12-10
Accepted: 2016-05-16