Influence of Ink Curing in UV LED Inkjet Printing on Colour Differences, Ink Bleeding and Abrasion Resistance of Prints on Textile

Digital printing techniques are increasingly present in the field of textile printing. Particularly prominent is the inkjet printing technique using water-based inks, UV LED inkjet printing also increasingly being in use. UV LED inkjet is primarily not intended for direct clothing printing; however, it can be used especially as a hybrid solution in the soft signage market. It is a great option for the printers that are not engaged only in textile printing, and want a more versatile print portfolio, extending it to non-clothing textile products, e.g. soft signage and non-wearable products. As these types of products often require colour reproduction of logos, accurate colour reproduction, good ink adhesion and sharpness are important just like in other printing technologies. In order to evaluate the impact of UV LED radiation amount on colour differences, ink bleeding and abrasion resistance, six different fabric samples (five woven and one nonwoven) were printed using a UV LED inkjet printer. Based on the results of colour difference, it was established that a reduction of UV radiation (by half the manufacturer’s recommended amount) had no effect on this parameter. However, perceptible colour differences were observed with the use of different M measurement conditions defined by the international standard ISO 13655-2017. Reducing the amount of UV radiation had no effect on the adhesion and durability of the printed ink. Small differences detected in these two parameters were mainly a consequence of the properties of textile materials and not of decreased UV radiation

Deinking of Screen-Printed Electrodes Printed on Invasive Plant-Based Paper

The deinking of paper-based printed electronics is a growing concern regarding the increase of printed electronics products. The benefits of using paper-based substrates instead of polymer or ceramic for the single-use printed electrodes can contribute to sustainability goals. The use of invasive plant species for making paper substrates for printed electronics is a unique opportunity to have several environmental benefits. In this study, the recycling issue of these products through the use of the deinking technique was evaluated. Screen-printed electrodes printed on an invasive plant-based paper and commercial cardboard were deinked, and their optical, morphological, and silver residues in paper and corresponding water extract were analyzed. The invasive plant-based paper had higher silver content in the recycled paper sheets, which influenced the optical and surface resistivity and residue ink particle number. On the other hand, the surface-treated cardboard had lower silver particle content after deinking, but higher silver concentrations in the water extract. The results indicate that ink-paper surface and ink-fibre interaction and adhesion is vital in the ink silver particles binding during the deinking process

The personality structure of toddlers and pre-school children as perceived by their kindergarten teachers

The present study was designed to analyse the personality structure of children aged one to seven, as perceived by their kindergarten teachers. In addition, gender differences were examined to determine whether kindergarten teachers perceived the personality characteristics of toddler and pre-school girls differently than those of boys. 508 randomly-selected Slovenian children were assessed by their kindergarten teachers using adapted Flemish Big-Five Bipolar Rating Scales. Four-factor structures that explained more than two-thirds of the variance emerged for teachers' personality ratings of children in each of the three age groups: toddlers, three- to five-year-olds and five- to seven-year-olds. However, five of the twenty-five scales, four of them referring to the Conscientiousness dimension, did not appear to be relevant when assessing individual differences in the toddlerhood. Intellect/Openness, as observed for the toddler sample, and the combined Conscientiousness-Intellect/Openness factor, extracted for each of the two older age groups, accounted for the greatest part of the variance. Extroversion was obtained as a second factor in each of the three age groups, while Emotional Stability showed relatively less stability across these groups. Agreeableness was clearly differentiated only in the oldest age group, emerging there for the first time as an independent factor. A few gender differences were found to be significant within the two groups of pre-school children, with girls consistently being rated higher in terms of Conscientiousness-Intellect/Openness

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

CHALLENGES IN DESIGNING SUSTAINABLE PAPER PACKAGING FROM INVASIVE PLANTS

<p><i>Consumer goods are usually enclosed in protective packaging to protect them from vibration and impact shocks during handling and transportation. Bio-degradable materials such as moulded pulp and honeycomb paper panels have emerged as formidable and sustainable alternatives to EPS. These materials exhibit distinct nonlinear and orthotropic behaviour and can be characterized by a relatively high stiffness. These makes them far from being regarded as an ideal cushioning material. Due to the inferior paper-based packaging performance, the improvement of protective and cushioning properties relay on the structural optimization of the packaging design. With proper design in terms of minimizing the vibration transfer path to the product itself and by avoiding extensive plastic deformation it is possible to significantly enhance cushioning performance of paper-based packaging even at multiple impacts. This requires advanced numerical models using finite element models using a highly nonlinear material models. This article presents the process of creating a numerical model for samples made from paper pulp, which also incorporate fibres from invasive plants, and introduces the method to identify its material properties. Leveraging this strategy enables to predict the static and cushioning characteristics of the pulp using numerical simulations. </i></p&gt

IoT electrochemical sensor with integrated ▫Ni(OH)2–NiNi(OH)_2–Ni▫ nanowires for detecting formaldehyde in tap water

Simple, low-cost methods for sensing volatile organic compounds that leave no trace and do not have a detrimental effect on the environment are able to protect communities from the impacts of contaminants in water supplies. This paper reports the development of a portable, autonomous, Internet of Things (IoT) electrochemical sensor for detecting formaldehyde in tap water. The sensor is assembled from electronics, i.e., a custom-designed sensor platform and developed HCHO detection system based on Ni(OH)2–Ni nanowires (NWs) and synthetic-paper-based, screen-printed electrodes (pSPEs). The sensor platform, consisting of the IoT technology, a Wi-Fi communication system, and a miniaturized potentiostat can be easily connected to the Ni(OH)2–Ni NWs and pSPEs via a three-terminal electrode. The custom-made sensor, which has a detection capability of 0.8 µM/24 ppb, was tested for an amperometric determination of the HCHO in deionized (DI) and tap-water-based alkaline electrolytes. This promising concept of an electrochemical IoT sensor that is easy to operate, rapid, and affordable (it is considerably cheaper than any lab-grade potentiostat) could lead to the straightforward detection of HCHO in tap water

DEVELOPMENT OF MOULDED PULP PROTECTIVE PACKAGING FROM ALTERNATIVE FIBERS

<p>Expanded polystyrene foam is a standard protection element for many packaging solutions which needs cushioning properties against mechanical stresses. While its protective functions are very good (lightweight good cushioning properties, easy to 3D-form with tooling) the environmental aspect of this material is questionable due to bulkiness (high space volume) and low rates of real and viable recycling infrastructure. Due to that producers have switched to fiber solutions (corrugated board inserts, fiber foams and biopolymer fiber composites) as an alternative solution. Even though this fiber-based alternative solutions are environmentally friendlier the overuse of cellulose fibers from wood sources can also be a burden on the environment. On the other hand, invasive alien plants due to their negative impact on biodiversity and other economic damage (riverbank degradation) are one of the possible solutions for producing fiber elements.</p><p>In this paper the development of moulded fiber cushioning elements, made from locally sourced invasive fiber alien plants (Japanese knotweed and Canadian goldenrod) and processed in Slovenia is presented as a part of the protective packaging system for household appliances. The fiber morphology and processing as well the prototyping of the moulding tools have influenced the mechanical properties needed for protection simulation due to different fiber bonding and entanglement. The obtained results serve as a basis for further development and structural analysis (finite elements modelling) of stress points for building simulation software for the use of alternative fiber solutions.</p&gt