To support circular economy and sustainability, the use of synthetic polymers should be minimized due to their excessive accumulation in the environment and low biodegradation rate which leads to a global waste problem. Thus, the quota of natural resources should be increased, as well as the use of agriculture and industrial waste or by-products as raw materials in industrial processes. Agro-industrial wastes were found to have high cellulose fiber potential which makes them an excellent resource for paper production. This study investigates the influence of artificial aging test on the stability of commercially available fiber based self-adhesive pressure sensitive labels (PSL), in which the facestock is made of 15% agro-industrial byproducts, 40% post-consumer recycled paper and 45% virgin wood pulp and compared to ones made of biobased polyethylene. The results showed that optical brighteners are present in the composition of fiber based PSL. Moreover, the fluorescence and UV-Visible spectroscopy results indicated that by the action of UV irradiation and temperature. The oxidation of cellulose was not found by FTIR spectroscopy, indicating its high stability.

In the present research, properties and performance of special effect printing inks were observed with the aim of obtaining a printed product with dual functional properties. Thermochromic liquid crystal-based printing ink (TLC) and UV-visible (daylight invisible) fluorescent inks (UVF), pure and as hybrid ink systems, were printed using a screen-printing technique on two types of uncoated paper substrates. Characterization of the paper substrates was performed, as well as detailed analysis of printed layers. Thickness, surface roughness, surface free energy, and adhesion parameters of printed layers were analysed. Spectral reflectance of pure UVF and TLC printing inks, as well as the spectral reflectance of the proposed hybrid ink systems were measured. The thermochromic effect of the TLC ink and hybrid systems was analysed. Microscopy was used to display the visual colour play effect and the effect of the fluorescence. Results of the measurements showed high compatibility of used materials in the proposed hybrid ink systems. Since the effect of luminescence and the colour play effect in the hybrid systems were preserved, it can be concluded that TLC/UVF hybrid ink systems can find their application in the development of functional packaging and in all other applications with special requirements for temperature monitoring and hidden information for different products.

In addition to satisfying a book binding criterion, the paperback should provide content moments. Its binding style must be adjusted to book purpose. In publishing longruns production, the perfect (adhesive) binding style with flexible hotmelt provides optimal binding durability with reasonable book price. Paperback should appeal to everyone through its visual-tactile senses. Taking the required actions in binding quality realization keeps track of comprehensive knowledge on various standardized paper substates (EN643:G3) that need to be wisely joined to realize perfect binding technique practices effectively. Moreover, designer technological awareness gained by experience provides potentials to understanding binding ability principles. The conducted research gives specific answers regarding paper cohesive capacity impact on consistency changes of adhesive bound book. It was concluded that higher paper drape capacity leads to increase of single sheet paper tension. Inappropriate bound book constructing was achieved although the flexible adhesive was used

Today, more than ever, sustainability is at its highest peak of daily interest for all business sectors, especially involving label and packaging industries. Usage of paper products made from alternative fiber sources is a very important topic that directly supports circular economy in everyday life. Although paper products should be recycled or re-used as secondary source of raw - material, a vast volume of products end their life at landfill, especially still in our region, causing excessive accumulation in the environment. For the purpose of this research, fluorescence intensity was measured on three different biodegraded pressure sensitive label material samples (PSL), made from agro-industrial and postconsumer waste. PSL materials utilized in this research are widely used for labelling various products, for example, wine, luxury products, food etc. and are compiled of 3 parts: facestock, adhesive and liner. PSL materials are enriched with optical brighteners to give the final product the desired optical properties. Fluorescence spectroscopy is a direct measure of optical brightener concentration within the substrate. Biodegradation was performed by usage of soil burial test under aerobic conditions. Laboratory soil burial experiments were conducted at room temperature (25±2°C) by placing the unprinted label paper substrates; facestock and adhesive (delaminated from the liner) horizontally in field soils in 2L laboratory glass containers, orientated adhesive down. The water content of the soil was adjusted to 40 % of its maximum water retention capacity. Substrates were buried for a period of 2, 4, 7, 10 and 13 days. Sample’s fluorescence intensity was measured before and after incubation in the soil containers. The samples were dug out after designated time, rinsed with distilled water to remove soil particles from the surface, air dried and measured. Fluorescence intensity was measured by using Ocean Optics USB2000+ spectrometer using a 30 mm wide integrating sphere under (8:di) measuring geometry with the addition of LSM Series LED light source at 365 nm. LED light source is operated via a smart controller during the measurement. A constant current of 0.140 A was kept stable in order to maintain a constant excitation light source with the aim to excite fluorescence whitening agents within the samples. As previously research shows the presence of optical brighteners in composition of fibre based PSL, fluorescence spectroscopy of biodegraded samples indicates decomposition of optical brighteners.

Today, the packaging industry is increasingly transforming, especially in terms of development of new sustainable materials and smart solutions in order to attract customers when choosing products, and to be competitive in the market. The use of colour changing packaging can give added value to the product since this kind of packaging can in that way interact with the consumer and provide a massage upon the product. During its lifecycle, the packaging can be exposed to the influence of various agents, for example the spilling of beverages over the printed labels. For this reason, the prints need to be resistant to certain agents, in this case, ethanol. In the end, the spill of ethanol can cause visual alterations of the print due to the colourants or the substrate itself not being resistant to the particular agent. Thermochromic inks are widely used as indicators for beverage packaging which can often be exposed to different concentrations of alcohol that may affect the functionality of that same indicator. Thermochromic inks differ in their composition from classic printing inks, which in the end results in lower stability when exposed to UV radiation and various chemicals. Thus, this study explores the influence of ethanol on the functionality of TC prints on labels. Different label papers were printed with one TC ink, with an activation temperature of 12°C. The samples were exposed to different concentrations of ethanol (8%, 12%, 25%, 35%, 42% and 96%) to simulate the real conditions in which it is possible to spill different alcoholic beverages on the thermochromic print on the packaging of an alcoholic product. It can be concluded that alcohol affects the stability of microcapsules even in the smallest concentrations because the largest changes of colour were observed at low temperature, while smaller colour changes determined at 23 ° C indicate that the classic process ink is more stable to the influence of alcohol. The results of this test showed that the chemical stability of the thermochromic print depends on both, the printing substrate and the external conditions to which the print is exposed. The results show that the proper choice of printing substrate can improve the stability of the thermochromic print in reaction with ethanol.

The increasing use of pressure-sensitive labels (PSLs), driven by growth in the packaging sector, raises concerns regarding material consumption and end-of-life management under evolving European packaging regulations. This study investigates the biodegradation potential of sustainable PSL facestocks produced from 15% agro-industrial by-products, 40% post-consumer recycled fibers, and 45% virgin wood pulp. Their biodegradation behavior was compared with bio-based polyethylene (PE) facestocks using laboratory-scale aerobic soil burial tests conducted for up to 28 days. Biodegradation was assessed through weight loss measurements, visual evaluation, Fourier transform infrared (FTIR) spectroscopy, and fluorescence analysis. Fiber-based facestocks exhibited significant degradation, reaching approximately 50–55% weight loss after 28 days, accompanied by structural changes in the cellulose matrix and reduced fluorescence intensity. In contrast, bio-based polyethylene facestocks showed negligible weight loss and only minor spectroscopic changes, indicating high stability under the tested conditions. The results demonstrate that fiber-based samples derived from agro-industrial and recycled sources possess substantially higher biodegradation potential than bio-based polymeric alternatives. These findings support the use of fiber-based PSL facestocks in applications requiring improved environmental compatibility.