Abstract

Important task is, considering sustainable development, the better utilisation of the yearly renewable biomass. Large proportion of the Great Hungarian Plain can not be utilised for food production as earlier, consequently it is open for cultivation of plants for industrial utilisation. In one of the Hungarian Agricultural Centres in Szarvas appropriate researchers have developed, patented and produced in large scale a new yearly renewable source of biomass called “Szarvas – I Industrial Grass”. Details related to agricultural production of the studied industrial grasses has also been discussed. The yearly production (metric tons/hectare) of biomass of industrial grass origin has been compared with those of conventional agricultural (e.g. straw, hemp, flax) and forest (e.g. Coniferous trees, Broad-leaved trees) plants. In cooperation with the Szarvas Research Group the Hungarian Paper Research Institute and with the a Research Group at the Department of Organic Chemistry and Technology of the Budapest University of Technology and Economics have started research activities for utilising this grasses in the paper industry. Complex analytical studies in separating different components of industrial grass proved the possibility of utilisation of its components as follows: extracted by hexane 1.5 %, hot water extraction 1.0%, holocellulose 65.0%, lignin 29%, ash content 1.0 %.

Keywords: industrial grass, renewable raw material, pulp- and paper industry

Abstract

The properties of classic and recycled papers with and without surface coatings were investigated by several methods. With the infrared attenuated total reflection spectroscopy, the molecular structure on sample surfaces was identified and analysed. This way the filler and coating pigment were detected and their amount on classic and on recycled papers. Ultraviolet/visible spectroscopy enables the reflectance and transmittance measurements. The most important result was detection of the optical brighteners and comparison of its amount in our paper samples. These results were compared with the calcium carbonate and china clay content in the bulk of examined papers, as calculated from the ash contents. Furthermore, differences between classic and recycled materials are discussed in more details.

Keywords: Recycled paper, FT-IR spectroscopy, UV/VIS spectroscopy, ash content.

Abstract

The suitability of recycled paper packaging materials for direct food contact applications is a major area of investigation. The evaluation of food contact suitability was conducted on two commercially produced recycled papers. The white top testliner and the fluting paper, commonly used as integral parts of corrugated container, were tested. Selected papers were also submitted to additional chemical cleaning, which was obtained by means of laboratory deinking flotation. The aim of this experiment was to evaluate a possible decrease in the amount of chemical contaminants in the deinked pulp after laboratory deinking flotation had been conducted. Two original paper samples as well as their corresponding deinked pulp handsheets were checked for the presence of potentially harmful substances that are usually found as residues of recycling procedures. Food contact analyses comprised determination of heavy metals (Cd, Pb, Hg), primary aromatic amines, diisopropylnaphthalenes (DIPN), phthalates and polychlorinated biphenyls (PCB) from aqueous or organic solvent extracts of paper samples. It was found that all amounts of measured contaminants were below the maximum limit of concentration proposed for these compounds by the European legislation. Furthermore, deinking flotation applied on the white testliner and fluting samples had a positive effect on the reduction of chemical contaminants from the deinked pulp.

Keywords: Food packaging, health safety, recycled fibres, chemical deinking flotation, reduction of contaminants.

Abstract

The aim of the research was to analyse the typographic changes in the newspaper Slovenec from its inception in 1873 – first it was published three times per week and after ten years, it became a daily newspaper – until its decline in 1945, as well as during its revival from 1991 until 1996. All the issues of the newspaper were analysed; however, the focus was put on those which were actually changed. By analysing the typeface style, it was established that for the content, the most widely used typestyle in the “old” newspaper (1873–1945) was modern, which was not always the case with titles and subtitles where decorative or lineal typestyles were used. On the other hand, the most widely used typestyle in the “new” newspaper (1991–1996) was transitional and was used for titles and subtitles, sometimes replaced by slab serif and lineal typestyles. The design of the “old” newspaper somehow followed the common European newspaper design, while in the “new”, modern newspaper, the design could not be detected. Therefore, the cultural heritage of the “old” newspaper was lost.

Keywords: cultural heritage, graphic design, newspaper, Slovenec, typography

Abstract

Surface topography of the printing plate and substrate and the printing ink composition are factors which highly influence ink transfer during flexographic printing process. Consequently, their influence on final imprint quality is certainly not in question. The research presented in this paper was aimed on determination of wetting characteristics of the printing plate and printing substrate, depending on printing ink composition, as well as their surface topology. Samples of printing ink were made with varying solvent and varnish concentration. Evaluation of the printing ink was made by measuring viscosity and the characterisation of surface topography of printing plate and PE foil was made by measuring roughness parameters. To determine wetting characteristics of the prepared ink samples on the used solids measurements of contact angle were performed. Obtained results showed that the ink composition has significant influence on the printing ink viscosity and on the wetting of the printing plate but on the printing substrate as well. The contact angle between printing ink and both investigated surfaces is decreasing by increasing the solvent and varnish concentration thereby resulting in worse wetting. The conducted research showed the importance of printing ink composition on the wetting of printing plate and printing substrate, consequently on the ink transfer from ink tray to imprint. Furthermore, one must monitor all observed parameters (surface topography, ink viscosity, wetting characteristics) in order to achieve best printing results.

Keywords: flexography, printing ink, polyethylene, contact angle, surface topography