March 2016

Gorazd Golob

Download

Improving the electrical performance and mechanical properties of conductive ink on thin compound substrate

Andreas Willfahrt, Thomas Fischer, Gunter Hübner
E-mail: willfahrt@hdm-stuttgart.de; fischert@hdm-stuttgart.de; huebner@hdm-stuttgart.de
Stuttgart Media University, Nobelstrasse 10, D-70569 Stuttgart, Germany

Abstract

In printed electronics applications, very often conductive lines have to be printed and there are several ink/paste and substrate combinations to choose from. Silver ink is usually used due to its high electrical conductivity. Carbon black and PEDOT:PSS are also very common. Substrates are available in a broad variety. Flexibility, good adhesion of the ink, processability, and a maximum processing temperature compatible with the curing temperature of the functional inks is important. If barrier properties, e.g. against the permeation of oxygen, carbon dioxide or water vapour are required, a compound substrate may be necessary, consisting of two or more layers of different materials. The motivation for this investigation was the need for improving the stability and processability of a given substrate chosen for printed batteries. The substrate consists of three layers, namely polyethylene (PE), aluminium and polyethylene terephthalate (PET). This compound foil is rather thin (100 µm) and very flexible. This is a major requirement for the application. The aluminium sandwiched between two polymer layers provides sufficient barrier properties. PET is commonly used as a substrate for printed electronic applications. PE is not as easy to print on, but with e.g. plasma treatment the adhesion of printing inks is sufficient. The weldability of PE is beneficial for the screen-printed battery application, although poor printability without surface treatment and the thermal mismatch of the asymmetric polymer compound (PE–PET) renders processing rather difficult. In this work, the authors examined a route for printing on PE without the need of pre-treatment of the substrate with plasma or corona. Instead, it was found that an UV-ink layer used as adhesion promoter provided sufficient adhesion and improved mechanical stability, i.e. cohesion of the successively printed silver ink layer. Additionally, the thermal treatment of the conductive ink was optimized by comparing heat press and hot stamp curing with batch oven curing.

Keywords: printed electronics, printed battery, conductive ink, UV-curing, laminated substrate

JPMTR 073 | 1513 Research paper
DOI 10.14622/JPMTR-1513
UDC 621.38 : 667.5 | 678.6-024.25

Received: 2015-12-25
Accepted: 2016-02-26

Improvement of abrasion resistance by over-varnishing in the case of water-based flexographic printing

Marta Gajadhur, Agnieszka Steć
E-mail: m.gajadhur@wip.pw.edu.pl; a.m.chrzanowskaa@gmail.com
Warsaw University of Technology, Faculty of Production Engineering, Institute of Mechanics and Printing, Department of Printing Technology, 2 Konwiktorska Street, 00-217 Warsaw, Poland

Abstract

The objective of the research was to analyse the abrasion resistance in flexographic printing with water-based inks, covered with different water-based varnishes. Print rub-off tests in the Ink Rub Tester were performed for one water-based ink and three different water-based varnishes used in flexographic printing. The rub-off resistance was evaluated by spectrophotometric methods and visual observations. The ΔE*_ab parameter was used in evaluation. The 3D optical microscope was used to analyse the obtained test results. It was observed that the varnishing process significantly improves the abrasion resistance of the prints. The type of the varnish used in the research does not have such an influence on improvement of abrasion resistance as that of the varnishing process itself. Considering the average surface roughness it could be deduced that the varnishing process increases the surface roughness for both the paper base and for the polyethylene foil. The greater the surface roughness the better is the resistance to abrasion.

Keywords: water-based ink, water-based varnish, surface roughness, spectrophotometric measurement, ΔE*_ab colour difference

JPMTR 074 | 1425 Research paper
DOI 10.14622/JPMTR-1425
UDC 655.1 : 667.7

Received: 2014-07-15
Accepted: 2016-03-01

Evaluation and use of gamut information in ICC output profiles

Reem El Asaleh, Diondra Filicetti, Abhay Sharma
E-mail: reem.elasaleh@ryerson.ca
School of Graphic Communications Management, Ryerson University, 350 Victoria Street, Toronto M5B 2K3, Canada

Abstract

A device’s color gamut is an important parameter in color managed workflows. With the increasing use of expanded gamut workflows and the need for more colorful products in large-format inkjet printing or packaging, the management and prediction of in-gamut colors is critical information for the content creator. When device color capability information is stored within the structure of an ICC profile, this information becomes readily available to any software utilizing the ICC profile in conjunction with an image or image data. A product may for example offer a gamut stain or warning to indicate to the user that the color under consideration is out of gamut of the destination print process. This research compares the gamut predictions of Adobe Photoshop, ArgyllCMS, BabelColor PatchTool, Esko Color Engine Pilot, Little CMS and MathWorks MATLAB. It is shown that the different tools may use different methods to determine the color gamut of a system. In general, the methods available include a Round Trip test, use of the ICC profile Gamut Tag and a Gamut Boundary Descriptor process. The Gamut Tag was read-in and displayed for different ICC profiles and differences in the tag contents was demonstrated. In total, 1729 CIELAB values, representing the PANTONE+ Solid Coated Library V2 were used and the percentage of in-gamut values using each software product was computed for different output print processes. There was a large difference in the predictions between the different products tested; the software tools variously predicted that 30–65 % of the library was in-gamut. A general philosophy of an ICC workflow is predictable result; while the ICC architecture is not intended to change a device’s gamut capabilities, it should be able to communicate accurate and consistent gamut information. As more and more software systems are starting to present gamut data, it is important that systems do not predict disparate results.

Keywords: color gamut, color management, lookup tables, PANTONE, ICC Gamut Tag

JPMTR 075 | 1505 Research paper
DOI 10.14622/JPMTR-1505
UDC 159.937 : 744.8

Received: 2015-08-03
Accepted: 2016-01-21

The influence of location-related factors on the perception of billboard advertising

Janine Spieß and Ulrich Nikolaus
E-mail: janine.spiess@me.com; ulrich.nikolaus@htwk-leipzig.de
Leipzig University of Applied Sciences (HTWK Leipzig), Faculty of Media, Gustav-Freytag-Straße, 42, 04277 Leipzig, Germany

Abstract

The impact that printed out-of-home advertisements have on the consumer’s perception is dependent on several location-related factors. For a long time, however, this influence was only indirectly gathered by measuring the relative performance of different locations of billboard advertising: Advertising agencies were traditionally only measuring consumer movement patterns and estimating “exposure opportunities”, but no real visual contacts. In this paper, the influence of the factors competition, distance, environmental complexity, occlusion and viewing angle, used with increasing frequency to improve those estimates on billboard perception, is analyzed using eye tracking technology. Two slightly different walks through a city environment are simulated, and changes in gaze behavior due to a variation of the aforementioned location-related factors are recorded and compared. The results confirm the impact of the environmental complexity and occlusion factors, whereas the influence of the other factors is lower or less conclusive. The results presented in this paper help to better understand how these factors affect human attention and allow for a more precise comparison of the relative importance of these location-related factors on the consumer’s perception. Furthermore, they might help to improve existing advertisement measurement systems.

Keywords: eye tracking, visual perception, human attention, billboard location, consumer’s perception

JPMTR 076 | 1601 Research paper
DOI 10.14622/JPMTR-1601
UDC 159.937 : 659.1

Received: 2016-01-07
Accepted: 2016-02-26

Features contributing to the genuineness of portraits on banknotes

Osamu Masuda^1,2, Marius Pedersen¹, Jon Y. Hardeberg¹E-mail: marius.pedersen@ntnu.no
¹ The Norwegian Colour and Visual Computing Laboratory, NTNU Norwegian University of Science and Technology, Teknologivegen 22, N-2815 Gjovik, Norway
² Department of Orthoptics and Visual Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata 950-3198 Japan

Abstract

Portraits have been thought to be one of the most important security features on banknotes for a long time. Portraits are often printed as the main feature of banknotes at a very high resolution in intaglio press. We tried to investigate on how important portraits actually are and what factors were contributing to the perceived genuineness of portraits on banknotes with a psychometric experiment. Banknotes were presented to subjects, enclosed in envelopes to cover the area other than the portrait, and the genuineness of those banknotes were rated. The factors affecting the rating were asked to the subjects at the same time. It was suggested that natural wear and tear strengthen the perceived genuineness of tested banknotes. Even though the inspection of the banknotes was restricted to on and around the portrait, the importance of the portrait was not high compared to other features, and a significant fraction of subjects answered that they paid no attention to any part of the face, which requires reflection and reconsideration of the use of human portraits as a security feature.

Keywords: intaglio printing, security printing, counterfeit deterrence, image quality, face perception

JPMTR 077 | 1508 Research paper
DOI 10.14622/JPMTR-1508
UDC 743 : 336.74 | 7.061

Received: 2015-11-01
Accepted: 2016-02-24

Formatting print layouts with CSS3

Christin Götz, Ulrich Nikolaus
E-mail: christin.goetz@pagina-tuebingen.de; ulrich.nikolaus@htwk-leipzig.de
Leipzig University of Applied Sciences (HTWK Leipzig), Gustav-Freytag-Str. 42, 04277 Leipzig, Germany;

Abstract

Cascading Style Sheets (CSS) have already been the de facto standard for the visual representation of digital content for some time now. However, advanced functions intended for the formatting of print layouts have been included only recently. With CSS level 3, which is still under development, several new features have been added to the standard, such as, for example, the definition of marginalia, footnotes, running heads or the support for advanced micro-typographic settings like OpenType features. In theory, these new features could be the key to a significant simplification of cross-media publishing, based only on the use of XML or (X)HTML and CSS3. In this paper, the current status of implementation of CSS3 features for the formatting of XML-based print layouts is discussed and its current support by rendering engines analyzed. The results suggest that CSS3 can be used at present for the formatting of simply structured content, but not for visually or semantically complex print layouts.

Keywords: eXtensible Markup Language, Cascading Style Sheets, cross-media publishing, electronic publishing, rendering engine

JPMTR 078 | 1512 Research paper
DOI 10.14622/JPMTR-1512
UDC 7.012 : 004.91

Received: 2015-12-22
Accepted: 2016-03-07