The influence of ink concentration and layer thickness on yellow colour reproduction in liquid electrophotography toner

U elektrofotografiji s tekućem tonerom, kolornigamut je često smanjen u žutom području što vodi do problema pri realizaciji otisaka fotografske kvalitete. Poznato je da koncentracija čestica pigmenta u tiskarskom bojilu i debljina nanosa na papirnatoj podlozi utjeću na konačnu kvalitetu otiska. U ovom radu varirana su upravo ta dva parametara, primjenjujući pritom žuto ElectroInk procesno bojilo te elektrofotografski tiskarski stroju HP Indigo. Za kolorimetrijsku i slikovnu analizu primjenjena je ECI tiskovna forma koja sadrži 378 definiranih polja. Dobiveni rezultati statistički su obrađeni metodom dvosmjerne analize varijacija. Studija je prikazana pomoću volumena kolornog gamuta, te površinske pokrivenost rasterskih elemenata (točkica). U radu je utvrđeno je da na kvalitetu obojenja prvenstveno utječe debljina nanosa žutog bojila, dok je utjecaj koncentracije žutih pigmenata minoran. Povećanje nanosa bojila sa jedanog na dva imalo je mnogo jači učinak od onog koji je realiziran povećanjem sa dva sloja na tri sloja.In liquid toner electrophotography, colour gamut is often diminished in the yellow region leading to problems with photo quality prints. It is known that the concentration of pigment particles in the printing ink and its thickness when applied on a paper substrate decisively influence final print quality. Variation of these two parameters for the yellow process ink was performed by modifying the printing process of the electrophotographic printer HP Indigo S1000. Printed colour patches of ECI test chart were analysed colorimetrically and using image analysis approach. Two-way analysis of variance was implemented to statistically assess the obtained results. Both studied responses – colour gamut volume and area coverage of halftone dots – were found to be primarily influenced by the yellow ink layer thickness and much less by the ink concentration. Increase from one to two ink layers had a significantly stronger effect on each of the two responses when compared to an additional increase from two to three layers

UV Ink-Jet printability and durability of stone and foil

he use of ultraviolet (UV) printing technology has impacted printing industry in last years due to its applicability on many different »absorptive« as well as »non-absorptive« printing materials. The printability of building materials and recycled foils is relatively unknown. For primary building materials like stones, functionality can be explored with the use of UV printing technology; increased visual, informative effect or even “creative printing” of buildings. Also several aspects of recycled foils reusability as a printing material could be find (printed packaging material or also like secondary building materials). In the present study, printability of the stone and recycled foil and durability of UV prints was explored by means of macroscopically and microscopically characterization. Results indicate that higher print quality can be achieved on polished stone and on coated foil, which surfaces have higher smoothness. Durability of UV prints at freezing is higher at unpolished stone and coated foil that is at materials with the higher surface energy

Porosity of natural stone and use of confocal laser scanning microscopy on calcitic marble aged in laboratory

Porosity is one of the key characteristics of natural stone, which influences ondurability as well as functionality of stone as building material. Further, deterioration processes themselves are also characterized by change of porosity. Different direct and indirect techniques can be used for porosity determination. In the following paper overview of these methods, as well as their advantages and disadvantages, is given. Confocal laser scanning microscopy (CLSM) is indirect (microscopic) technique. Despite its numerous advantages, among which 3D visualizationof pore structure is of major importance, this technique is less known in the area of building materials. An example how CLSM can be applied for qualitative and quantitative evaluation of porosity of calcitic polygonal granoblastic marble is given in this paper. Studied marble has been, despite of its poor durability, often used as building material, especially in the case of claddings. It is shown that thermal hydric factors of deterioration can influence porosity significantly,especially formation of intergranular cracks.This kind of deterioration can be successfully evaluated with use of CLSM method, if samples are suitable prepared and if suitable image analysis tools are developed

Humidity Sensors Printed on Recycled Paper and Cardboard

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

Humidity Sensors Printed on Recycled Paper and Cardboard

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

Pharmaceutical packaging and ID cards with printed antennas of RFID tags

The integration of RFID tags in different applications is important in order to gain greater functionality in products. Upon packaging, box tracking in logistics or in the supply chain can easily be achieved [1]. High manufacturing costs have led to the search for alternative manufacturing methods at an ultra-low cost and various printing processes have been considered such as inkjet, gravure, flexo, offset and screen printing. Currently, investigations are focused on the use of these printing technologies for the mass production of RFID directly on different printing materials such as papers, cardboards and foils [2–12]. This paper is an upgrade of our preliminary research [13] focused on antenna design and optimization of printing conditions. The analysis of the readability of UHF RFID tags, which were printed on real pharmaceutical packaging (of tablets) and on ID cards with printed and multi-layered laminated plastic cards were done. Two different antenna designs were printed. The first one on a packaging box and the second one on a foil layer which was then laminated with seven different foil layers. For printing thermal drying silver conductive printing ink was used. The NXP plastic strap chips were integrated with printed antennas using conductive glue. We found that printed antennas of UHF RFID tags and inline chip integration can swap the RFID tag label on packaging and RFID tag inlays in ID cards with printed ones. Preliminary results are promising, but to achieve better performance significant improvements have to be made in the near future