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1

Assessment of conductive properties of flexographic inks

Hamerliński J., Hoppe J., Krzyżkowski J.

Acta Poligraphica

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2016

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Vol. 7

7--13

EN

The article presents results of assessment of flexographic inks for their conductive properties. Conductive inks for printed electronics are much more expensive than standard graphic inks, thus it was interesting to find out if the standard graphic inks can be a viable substitute in some cases. Several formulations of solvent-based and water-based flexographic inks were assessed to discover that the surface resistance of layers printed with these inks widely differs. Some inks are not conducting until a certain film thickness is reached. The inks printed on paper in general are more conductive than printed on non-absorbent substrates, and their conductive properties do not change with time. The best results obtained with graphic inks are comparable to the properties of specifically formulated flexographic conductive ink. This indicates that standard graphic inks can be used for some applications where resistivity in the single kOhm per square range is required, and some changes to the formulation may lead to a hybrid ink with good printability and conductivity.

PL

W artykule przedstawiono wyniki badań dotyczące oceny właściwości przewodzących standardowych farb fleksograficznych. Z uwagi na wysoką cenę farb przewodzących stosowanych do druku elementów elektronicznych, możliwość wykorzystania w tej roli farb graficznych jest interesującym rozwiązaniem dla przemysłu poligraficznego. Zbadano kilka dostępnych na rynku standardowych farb fleksograficznych (rozpuszczalnikowych oraz wodorozcieńczalnych), przy czym stwierdzono, że ich rezystancja powierzchniowa znacząco się różni. Niektóre farby zaczynają wykazywać właściwości przewodzące dopiero po przekroczeniu pewnej grubości warstwy. Farby nanoszone na papier wykazują z reguły lepszą przewodność niż farby nanoszone na podłoża niechłonne, a ich właściwości elektryczne nie ulegają zmianie z czasem. Niektóre zbadane farby osiągnęły przewodność porównywalną ze specjalistyczną farbą przewodzącą opracowaną dla techniki drukowania fleksograficznego. Wskazuje to na możliwość zastosowania standardowych farb graficznych do druku niektórych elementów elektronicznych, gdzie rezystancja powierzchniowa na poziomie pojedynczych kiloomów na kwadrat jest wystarczająca. Wyniki badań sugerują także, iż możliwe jest opracowanie modyfikacji farb graficznych w kierunku stworzenia farby hybrydowej, posiadającej dobre właściwości elektryczne i graficzne jednocześnie.

2

Spectral analysis of parametric two degrees- of-freedom system

Krzyżkowski J., Pyryev Y.

Challenges of Modern Technology

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2015

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Vol. 6, no. 4

9--13

EN

In this paper model of a vibrating system of two rotating, stressed to each other and periodically losing contact cylinders is presented. The model is described by two-degrees-of-freedom Hill's differential equations system, which was numerically solved. Spectra of the vibrations were analyzed in here.

3

Investigation on lineworks printed with different types of flexographic printing forms for purposes of printed electronics

Krzyżkowski J., Dąbrowa T., Hamerliński J., Śleboda P.

Challenges of Modern Technology

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2015

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Vol. 6, no. 3

3--9

EN

Nowadays one can observe fast development of materials and technologies dedicated to inexpensive mass production of electronic devices with conventional printing techniques. One of them is flexography. In this paper investigation on quality of lineworks printed with flexographic printing technique for purposes of printed electronics is presented. There was analysed influence of different printing forms on printed elements reproduction accuracy. Results obtained with conventional graphic ink with commercially available conductive ink were compared as well. Aspects which should be taken under consideration when implementing flexography to printed electronics applications have been specified.

4

Badanie odwzorowania elementów kreskowych w technice wklęsłodruku przy użyciu cylindrów formowych grawerowanych mechanicznie z zastosowaniem różnych metod i parametrów

Dąbrowa T., Hamerliński J., Hoppe J., Krzyżkowski J., Śleboda P., Wojciechowski M.

Acta Poligraphica

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2014

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Vol. 3

9--27

EN

Gravure printing is used for high-volume production of high quality magazines and packagings. The method of printing form preparation, while satisfying the requirement for uniform and ink transfer and low image granularity, restricts the precision of linework elements, especially those used in securities and special printing. To overcome this problem, novel engraving methods have been developed. The Paper presented deals with the quality of linework reproduction using different combination of engraving parametres. The quality was assessed by printing a prepared test image containing commonly used linework elements, while using forms engraved with different parametres combinations. A printout with standard engraving parameter set was used as a reference point. Line separation, details reproduction, image resolution and ink optical density were measured to quantify the results. Printing parameters were identical for all samples. It was found that engraving parametres have negligible influence on text readability, but other linework elements, e.g. microlines, Landolt rings and concentric circles, may differ significantly if printed from a form engraved with different parameters. Moreover, the linework element reproduction depends on relation of element direction and engraving direction, as well as the convergence of engraving screen and linework elements’ distance. The minimum linework thickness required for stable reproduction for all electromechanical engraving methods and parametres was found to be between 100 and 150 microns.

5

Cylinder Gap Shock and its Impact on Quality of Prints in Offset Printing Technique

Krzyżkowski J., Pyryev Y.

Challenges of Modern Technology

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2013

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Vol. 4, no. 2

23--30

EN

There are many factors in offset printing technique, which determine the final quality of the printouts. Next to ink, dampening liquid and paper properties, significant role plays here construction of printing unit and its technical condition. Many works, where problem of vibrations was investigated, point canals in plate and blanket cylinders as source of vibrational excitation in printing unit. The canals may generate vibrations of inking and dampening rollers, as well cylinders themselves. If wear of bearings, looseness and unbalance of rotating cylinders and rollers will be additionally taken into account, there may be expected, that excited vibrations will seriously influence on the results obtained during printing process. Some undesired artifacts, for instance, cross stripes may be noticeable on the prints then. The main scope of the researches presented in this paper was to find relation between vibrations in offset printing unit and their influence on quality of the printed image. For this purpose, while printing, measurements of vibrations of printing unit have been made. Afterwards printed test image have been precisely analyzed in search of undesired phenomena, which can be an effect of excessive vibrations in printing unit. Then comparison between position of the artifacts on the prints and the results of vibration measurements has been made. Effects of the experiment are presented in this paper.

6

Parametric vibrations in printing unit of offset printing machine

Pyryev Y., Krzyżkowski J.

Vibrations in Physical Systems

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2012

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Vol. 25

335--340

EN

Vibrations in printing machines are serious problem, which influences on the run of printing process and the quality of the printouts as well. Ones of the most important sources of vibrations are printing units, in which periodically changing stiffness excites parametric vibrations. In this paper, printing unit of offset printing machine is modelled as a two degree-of-freedom system, which is described by a system of parametric differential equations. Some analyses of this model’s behaviour are presented as well as conditions, in which parametric resonance in such systems may occur.

7

Construction of cylinders in offset printing presses and its vibratory consequences

Krzyżkowski J., Pyryev Y.

Challenges of Modern Technology

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2012

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Vol. 3, no. 1

15--18

EN

Vibrations in offset printing presses are serious problem, which beside influence on machines’ parts, are also source of problems with printing process and achieving prints of right quality. In this paper construction of offset printing unit is presented. Reasons of vibrations and their types in printing units are shortly described. Moreover, this article shows the role, which some of printing unit’s elements play in resisting of vibrations appearance. There is model of printing unit of sheet-fed offset printing machine presented in here. Model is described by the system of differential parametric equations. There were computer simulations realized, that pointed conditions, which should be fulfilled, so the parametric vibrations occurred.

8

Analysis of vibration of printing unit of offset printing press

Krzyżkowski J., Pyryev Y.

Challenges of Modern Technology

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2011

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Vol. 2, no. 2

31--34

EN

There are several causes of vibration of off set printing presses. Major are cyclic work of feeders and deliveries, gaps with mechanisms for fixing plate and blanket in cylinders of printing pair and inappropriate stress between those cylinders. All mentioned above causes increased exploitation of bearings, gears driving cylinders and other parts of the printing press. The consequences of vibration are also breaking of paper web and such artefacts as doubling and streaking on the prints. In this paper printing pair cylinders of lithographic printing press are described as a two-degree of freedom model. Solution of a system of differential equations, which describes this model shows influence of vibration of printing unit cylinders on the fluctuation of the ink film thickness on the prints (magnitude of streaking phenomenon).