December 2021

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Gorazd Golob


The news section of the Journal: Topicalities

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Modeling and analysis of the ink splitting factors influence on ink filling in offset printing 

Mykhailo Verkhola, Ulyana Panovyk, Myron Kalytka and Oleksandra Babych


Department of Automation and Computer Technology, Ukrainian Academy of Printing, Pid Holoskom St. 19, 79020 Lviv, Ukraine


Currently, offset printing technology is used to manufacture a wide range of printing products. Given the trends to reduced print circulation, the issue of increasing the competitiveness of printing equipment by reducing the cost of ink and paper in printing press setup remains relevant, which is most effectively achieved by improving the accuracy of its pre-adjustment. The technical condition of printing equipment, the properties of ink and paper, climatic conditions in the production room, and other factors affect the distribution of ink flows in the inking and printing system (IPS). Obviously, the change in the ink splitting factors, which occurs under the influence of these aspects, will affect the accuracy of the pre-adjustment. The purpose of this study is to model and research the effect of ink splitting factors in the contact zones of rollers and cylinders on the process of its distribution and transmission in the IPS and its ink filling and to obtain information about the weight of ink splitting factors on the accuracy of the previous adjustment. To solve this problem, computer technology has been developed using the methods of automatic control theory, methods of mathematical modeling, theory of discrete systems, and MATLAB-Simulink interactive environment. A mathematical model of offset IPS was developed to implement the research technology, which describes the operation modes of all its components. The IPS simulator of the offset machine is constructed, which reproduces the technology of printing process. Simulation modeling and analysis of the ink splitting factors that influence the process of ink distribution and transmission in the IPS are carried out. The need to determine the reliable value of the ink splitting factors in the contact zones of the rollers and cylinders is substantiated. Computer technology makes it possible to determine the ink amount accumulating in the IPS during printing process and the ink thickness and volume on the surfaces of the imprints.

Keywords: mathematical model, signal graph, inking and printing system simulator, ink flow distribution, ink volumes

JPMTR-2113 Original scientific paper | 153
DOI  10.14622/JPMTR-2113
UDC 681.6-035.67|53.07

Received: 2021-09-09
Accepted: 2021-12-03

Designing the Spatial star as a three-dimensional derivate of the Siemens star and developing the methods to determine the accuracy, resolution and spatial frequency response from a 3D scan of the Spatial star 

Sven Ritzmann and Peter Urban


University of Wuppertal, School of Electrical, Information and Media Engineering, Rainer-Gruenter-Straße 21, D.42119 Wuppertal


In many cases investigating a 3D scan of a real object is more time and cost effective than investigating the real object. This is especially the case if related objects are spread over several collections around the world. Investigation results based on a 3D scan depend on the accuracy and resolution of the specific 3D scan. This paper lays the foundation to define the specific characteristics of a workflow to determine the accuracy, resolution and spatial frequency response of any 3D scan. Therefore, it adapts the operating principle of the Siemens star to the third dimension. The result is the Spatial star, a digital three-dimensional derivate of the Siemens star that provides the required information. This paper also develops the methods to determine the accuracy, resolution and spatial frequency response from a 3D scan of the Spatial star. During this process a 3D scan is restructured into a unified matrix representation that ensures comparability between different 3D scans and fits documentation purposes. To validate the developed methods, the paper uses a set of partly simulated 3D scans of the Spatial star.

Keywords: 3D imaging, quality assessment, optical transfer function, modulation transfer function

JPMTR-2109 Original scientific paper | 154
DOI  10.14622/JPMTR-2109
UDC 658.5:004.352|62-5(18)

Received: 2021-08-09
Accepted: 2021-12-03

Glucomannan-xylan blend biofilms for food packaging: preparation and evaluation of filmogenic solutions and biofilms  

 Kholoud Al-Ajlouni, Paul D. Fleming and Alexandra Pekarovicova 


Chemical and Paper Engineering, Western Michigan University, USA 


 Food packaging nowadays requires a sustainable, biodegradable, and friendly to the environment wrapping films. After cellulose, the hemicellulose in plants and grasses is the potential source for the biofilms. Konjac glucomannan is one of the hemicelluloses used to synthesize wrapping films. In this research, we conducted three sets of experiments: we formulated pure glucomannan biofilms, glucomannan–xylan blend biofilms with nano-fibrillated cellulose (NFC), and finally glucomannan–xylan blends without NFC. We studied the rheology of the filmogenic solution of the blends, before casting, and the physical and mechanical properties of the biofilms. The biofilms consisted from: glucomannan, xylan, NFC as reinforcement polymer, Surfynol 104 PA as surfactant and Sorbitol as a plasticizer. Pure glucomannan was stiff and viscous and in some cases showed a faceting phenomenon. In general, blended biofilms exhibited better properties with the presence of NFC in the formulation. 

Keywords: faceting, nano-fibrillated cellulose, stretch wrapping, shear thinning, frequency sweep

JPMTR-2116 Original scientific paper | 155
DOI  10.14622/JPMTR-2116
UDC 577.1|62-4:547.4:621.798 

 Received: 2021-12-08
Accepted: 2021-12-30