Pulp and Paper Institute

Ljubljana, Slovenia

Pulp and Paper Institute

Ljubljana, Slovenia
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Plesa T.,University of Ljubljana | Mraovic M.,Pulp and Paper Institute | Kavcic U.,Valkarton Rakek d.o.o. | Pivar M.,University of Ljubljana | Muck T.,University of Ljubljana
International Conference on Digital Printing Technologies | Year: 2016

The research examines the printing of passive electrical circuit elements, specifically of printed switches. In the introduction, the functional printing and printed electronics are defined, and the composition and functioning of printed switches are explained. The aim of the research was to create printed switches of different sizes and shapes with screen printing, and to explore the optimal conditions for their operation. In the experimental part, two types of switches were developed, namely with sensors based on two electrodes (electrical capacitor) and sensors based on a single electrode. Various forms of sensors were designed and printed on printing materials (special paper for printed electronic, recycled paper and foil) with functional conductive ink and the screen-printing technology. Printed sensors were varnished and laminated. On each of them, measurements were performed and the influence of various factors was evaluated, i.e. the shape and size of capacitors/electrodes, printing material, air moisture, varnishing and laminating. Finally, the functionality of sensors was analysed and the sensors were applied onto a packaging as switches for turning on an LED light. © 2016 Society for Imaging Science and Technology.


Hladnik A.,University of Ljubljana | Muck T.,University of Ljubljana | Stanic M.,Kenniscentrum Papier en Karton | Cernic M.,Pulp and Paper Institute
Acta Polytechnica Hungarica | Year: 2012

The Fast Fourier transform was applied to demonstrate how to solve two related technological problems in the fields of papermaking and printing using ImageJ, a public domain Java image processing program. By converting a digital image of a multifunctional office paper surface from the spatial- into the frequency domain followed by an appropriate filtering, it was possible to identify and separate two different types of patterns - non-periodic structures such as formation, and periodic structures such as fabric marks. In addition, the moiré pattern, a negative phenomenon often occurring in printing, was eliminated to a large extent. The method proved to be a valuable tool in investigating and quantifying various paper and print quality-related phenomena.


Balabanic D.,Pulp and Paper Institute | Balabanic D.,University of Nova Gorica | Rupnik M.,University of Maribor | Klemencic A.K.,University of Ljubljana
Reproduction, Fertility and Development | Year: 2011

There is increasing concern about chemical pollutants that are able to mimic hormones, the so-called endocrine-disrupting compounds (EDCs), because of their structural similarity to endogenous hormones, their ability to interact with hormone transport proteins or because of their potential to disrupt hormone metabolic pathways. Thus, the effects of endogenous hormones can be mimicked or, in some cases, completely blocked. A substantial number of environmental pollutants, such as polychlorinated biphenyls, dioxins, polycyclic aromatic hydrocarbons, phthalates, bisphenol A, pesticides, alkylphenols and heavy metals (arsenic, cadmium, lead, mercury), have been shown to disrupt endocrine function. These compounds can cause reproductive problems by decreasing sperm count and quality, increasing the number of testicular germ cells and causing male breast cancer, cryptorchidism, hypospadias, miscarriages, endometriosis, impaired fertility, irregularities of the menstrual cycle, and infertility. Although EDCs may be released into the environment in different ways, the main sources is industrial waste water. The present paper critically reviews the current knowledge of the impact of EDCs on reproductive disorders in humans. © CSIRO 2011.


Mraovic M.,Pulp and Paper Institute | Muck T.,University of Ljubljana | Pivar M.,University of Ljubljana | Trontelj J.,University of Ljubljana | Pletersek A.,AG ams R&D
Sensors (Basel, Switzerland) | Year: 2014

Research, design, fabrication and results of various screen printed capacitive humidity sensors is presented in this paper. Two types of capacitive humidity sensors have been designed and fabricated via screen printing on recycled paper and cardboard, obtained from the regional paper and cardboard industry. As printing ink, commercially available silver nanoparticle-based conductive ink was used. A considerable amount of work has been devoted to the humidity measurement methods using paper as a dielectric material. Performances of different structures have been tested in a humidity chamber. Relative humidity in the chamber was varied in the range of 35%-80% relative humidity (RH) at a constant temperature of 23 °C. Parameters of interest were capacitance and conductance of each sensor material, as well as long term behaviour. Process reversibility has also been considered. The results obtained show a mainly logarithmic response of the paper sensors, with the only exception being cardboard-based sensors. Recycled paper-based sensors exhibit a change in value of three orders of magnitude, whereas cardboard-based sensors have a change in value of few 10s over the entire scope of relative humidity range (RH 35%-90%). Two different types of capacitor sensors have been investigated: lateral (comb) type sensors and modified, perforated flat plate type sensors. The objective of the present work was to identify the most important factors affecting the material performances with humidity, and to contribute to the development of a sensor system supported with a Radio Frequency Identification (RFID) chip directly on the material, for use in smart packaging applications. Therefore, the authors built a passive and a battery-supported wireless module based on SL900A smart sensory tag's IC to achieve UHF-RFID functionality with data logging capability.


Klemencic A.K.,University of Ljubljana | Bulc T.G.,University of Ljubljana | Balabanic D.,Pulp and Paper Institute
Periodicum Biologorum | Year: 2010

Background and Purpose: A chemical-free water treatment system consisting of fibre filters, ultrasound, and UV for fish farming was operated in a fishpond to study its effect on the control of algae compared with a non-treated fishpond. Materials and Methods: Phytoplankton and phytobenthos were sampled in both ponds, at the same time Chlorophyll-a, nitrates (NO 3), orto-phosphates (PO 4), pH, water temperature and saturationwere monitored. Results and Conclusions: The results showed that ultrasonication caused efficient sedimentation of planktonic algae. The number of determined algal species was lower in the treated pond. The proportion of green algae and Cyanobacteria was higher in the non-treated pond, and diatoms were the predominant group of algae in the treated pond. The species Oedogonium sp., Mougeotia sp. and Spirogyra sp. were »tolerant« to ultrasonic irradiation. The successful control of algae using the chemical-free water treatment system suggests that the Chem-free water treatment system can be a practical method to control algal bloom in fish farms.


Mraovic M.,Pulp and Paper Institute | Muck T.,University of Ljubljana | Pivar M.,University of Ljubljana | Trontelj J.,University of Ljubljana | Pletersek A.,Ams Ag Inc.
Sensors (Switzerland) | Year: 2014

Research, design, fabrication and resultsof various screenprinted capacitive humidity sensors is presented inthis paper. Two types of capacitive humidity sensors have been designed and fabricated via screen printing on recycled paper and cardboard, obtained from the regional paper and cardboard industry.As printing ink, commercially available silver nanoparticle-based conductive ink was used. A considerable amount of work has been devoted to the humidity measurement methods using paper as a dielectric material. Performances of different structures have been tested in a humidity chamber. Relative humidity in the chamber was varied in the range of 35%-80% relative humidity (RH) at a constant temperature of 23 °C. Parameters of interest were capacitance and conductance of each sensor material, as well as long term behaviour. Process reversibility has also been considered. The results obtained show a mainlylogarithmic response of the paper sensors, with the only exception being cardboard-based sensors. Recycled paper-based sensors exhibit a change in value of three orders of magnitude, whereas cardboard-based sensors have a change in value of few 10s over the entire scope ofrelative humidity range (RH 35%-90%). Two different types of capacitor sensors have been investigated: lateral (comb) type sensors and modified, perforated flat plate type sensors. The objective of the present work was to identify the most important factors affecting the material performances with humidity, and to contribute to the development of a sensor system supported with a Radio Frequency Identification (RFID) chip directlyon the material, for use in smart packaging applications. Therefore, the authors built a passive and a battery-supported wireless module based on SL900A smart sensory tag's IC to achieve UHF-RFID functionality with data logging capability. © 2014 by the authors; licensee MDPI, Basel, Switzerland.


Balabanic D.,Pulp and Paper Institute | Balabanic D.,University of Nova Gorica | Hermosilla D.,Complutense University of Madrid | Merayo N.,Complutense University of Madrid | And 2 more authors.
Journal of Environmental Science and Health - Part A Toxic/Hazardous Substances and Environmental Engineering | Year: 2012

There is increasing concern about chemical pollutants that have the ability to mimic hormones, the so-called endocrine-disrupting compounds (EDCs). One of the main reasons for concern is the possible effect of EDCs on human health. EDCs may be released into the environment in different ways, and one of the most significant sources is industrial wastewater. The main objective of this research was to evaluate the treatment performance of different wastewater treatment procedures (biological treatment, filtration, advanced oxidation processes) for the reduction of chemical oxygen demand and seven selected EDCs (dimethyl phthalate, diethyl phthalate, dibutyl phthalate, benzyl butyl phthalate, bis(2-ethylhexyl) phthalate, bisphenol A and nonylphenol) from wastewaters from a mill producing 100 % recycled paper. Two pilot plants were running in parallel and the following treatments were compared: (i) anaerobic biological treatment followed by aerobic biological treatment, ultrafiltration and reverse osmosis (RO), and (ii) anaerobic biological treatment followed by membrane bioreactor and RO. Moreover, at lab-scale, four different advanced oxidation processes (Fenton reaction, photo-Fenton reaction, photocatalysis with TiO2, and ozonation) were applied. The results indicated that the concentrations of selected EDCs from paper mill wastewaters were effectively reduced (100 %) by both combinations of pilot plants and photo-Fenton oxidation (98 %), while Fenton process, photocatalysis with TiO2 and ozonation were less effective (70 % to 90 %, respectively). © 2012 Copyright Taylor and Francis Group, LLC.


Balabanic D.,Pulp and Paper Institute | Balabanic D.,University of Nova Gorica | Klemencic A.,University of Ljubljana
Fresenius Environmental Bulletin | Year: 2011

Paper mills generate varieties of pollutants depending upon the type of the production process. Raw and biologically treated effluents from two paper mills with different production processes and different biological treatment plants were analysed by COD, BOD 5, AOX as well as by phthalates, bisphenol A, and nonylphenol which are potential endocrine disrupting compounds. Removal efficiency of aerobic and combined aerobic/anaerobic wastewater treatment plants were studied for investigated compounds. The results indicated that dimethyl phthalate, diethyl phthalate, dibutyl phthalate, di(2-ethylhexyl) phthalate, benzyl butyl phthalate, bisphenol A, and nonylphenol were present in raw and biologically treated paper mill effluents. The removal efficiencies of aerobic and combined aerobicanaerobic biological wastewater treatment plants were 87% and 87% for dimethyl phthalate, 79% and 91% for diethyl phthalate, 73% and 88% for dibutyl phthalate, 84% and 78% for di(2-ethylhexyl) phthalate, 86% and 76% for benzyl butyl phthalate, 74% and 79% for bisphenol A, and 71% and 81% for nonylphenol, respectively. Despite relative high removal efficiency of biological wastewater treatment plants for investigated compounds, the concentrations of nonylphenol in treated paper mill effluents exceeded limits of 0.3 μg/L according to Directive (2008/105/EC). © by psp.


Peterlin S.,Pulp and Paper Institute | Planinsek O.,University of Ljubljana | Moutinho I.,Portucel Soporcel Group | Ferreira P.,University of Coimbra | Dolenc D.,University of Ljubljana
Cellulose | Year: 2010

Unbleached TMP spruce fibers were stepwise delignified by KMnO4/H2SO4 and five partly delignified samples were obtained. Fibers were characterized in terms of carboxylic groups, lignin and hemicelluloses content. IGC measurements were performed in the untreated fibers and in the five delignified fiber samples, as well as in microcrystalline cellulose (MCC). Different parameters, such as the dispersive component of the surface free energy (γd s), the free energy and the enthalpy of adsorption with nonpolar probes (δGd a and δHd a, respectively), as well as the specific interactions with polar probes, quantified by the free energy and the enthalpy of adsorption (δGs a and δHs a, respectively), were determined. The values of γd s and δGd a are for all samples lower than for pure cellulose and vary slightly with the amount of lignin. For small contents of lignin, the values of δGs a of the acidic probes decrease with the delignification whereas those of the basic probes increase, pointing to a rather acidic character of the fibers due to the increase of the relative amount of the carbohydrates. The values for MCC corroborate these findings. Despite the substantial variation in the carboxylic group content during delignification, no clear tendencies were detected regarding the affinity with the basic probes. © 2010 Springer Science+Business Media B.V.


Kaluza L.,Kolicevo Karton | Sustarsic M.,Pulp and Paper Institute | Rutar V.,Pulp and Paper Institute | Zupancic G.D.,Institute for Environmental Protection and Sensors
Bioresource Technology | Year: 2013

The possibility of introducing the thermo-alkali hydrolysis of Waste-Activated Sludge (WAS) was investigated, in order to enable the use of its solid residue as a raw material in cardboard production and the use of its liquid portion for anaerobic digestion in an UASB reactor. The evaluation of the hydrolysis at pH>12 and T=70°C showed that the microbe cells were disrupted with more than 90% efficiency in less than 2h. The solid portion was hygienised, therefore making it possible to integrate it into the cardboard production as a raw material for less demanding cardboards. Up to 6% addition of the liquid portion of hydrolysed WAS to wastewater decreased the specific biogas production in a pilot-scale UASB from 0.236 to 0.212m3/kgCOD, while the efficiency of the COD removal decreased from 80.4% to 76.5%. These values still guarantee an adequate treatment of the wastewater and an increased biogas production by 16%. © 2013 Elsevier Ltd.

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