Paper is one of the most important materials for packaging and the demand for
this material is constantly increasing. The printing and packaging
industries are researching alternative sources of ...fibre, to produce more
environmentally friendly paper without compromising quality. As a packaging
material, paper must meet high strength requirements, and it has to exhibit
acceptable surface properties to preserve the printing quality. This
research had two objectives: to produce paper made from pulp of recycled
fibre reinforced with virgin straw fibre and to evaluate the print quality
on such papers. Straw pulp used for this purpose was obtained from three
cereal crops: wheat, barley, and triticale. The paper produced was printed
by using five printing techniques. Rubbing stability was evaluated by the
difference in colour and reflectance spectra before and after performing rub
tests and a comparison was made for the best interaction of paper and ink
determined by the printing technique. For the prints with the highest colour
difference after the rub test, the surface of the rub test receptor
(uncoated recycled paper) was examined for signs of ink transfer during the
test and the areas of transferred ink coverage were calculated on their
processed microscopic images.
Paper performance qualities strongly depend on the origin of cellulose fibers. Awareness of environmental issues and sustainable development has led to the increase in the use of recycled printing ...papers. Recovered fibers are often used as a substitute for virgin wood fibers in the production of certain types of papers. As recovered fibers cannot provide the same quality level of paper products as virgin wood fibers, alternative sources of virgin cellulose fibers need to be identified. The aim of this research was to analyze the printability of laboratory papers made of different contents of straw pulp. Therefore, the printing papers were formed using straw pulp of three different cereal species (wheat, barley, and triticale) and mixing them with recycled newsprint in different weight ratios. The printability of these laboratory papers was analyzed by classifying dot reproduction quality based on four dot reproduction attributes. Printed dot reproduction greatly affects the quality of reproduction in graphic products, as dots are the most important element in multi-color reproduction of texts and images. It was confirmed that laboratory papers containing straw pulp provide the same or even better dot reproduction quality than laboratory control papers formed only of recycled newsprint.
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Packaging and labels are used for a variety of products and have become an indispensable part of daily life, while products without labels or packaging cause uncertainty among consumers. The global ...trend is to reduce the amount of packaging waste by recycling and reusing the same material or using other available waste raw materials. With large quantities of stalks remaining discarded in the fields after harvest each year, cereal straw is emerging as an alternative source of lignocellulosic fibers for secondary green packaging and labels. In this study, the usability of printed papers with discarded lignocellulosic fibers by offset and gravure printing processes for secondary green packaging and labels was observed based on the qualitative parameters of reproduction and ink penetration into the printing substrate. From the obtained results, it can be concluded that gravure prints have greater penetration of the ink into the printing substrate, resulting in more uneven surface coverage with printing ink, compared to offset prints, where the viscosity of the ink and the printing process itself have the greatest influence. Therefore, these substrates with discarded lignocellulosic fibers can be used for secondary green packaging and labeling printed by the offset printing process, while gravure printing requires an additional coating or a larger amount of filler in the paper structure.
Today the print quality of digital printing techniques has improved and is considered satisfactory and competitive to analogue techniques for certain graphic products. Satisfactory print quality ...mostly depends on the interaction of ink and printing substrate where ink penetration has an important role. Namely, the ink penetration affects the parameters that describe the print quality together with visual appearance of print density and mottling. Therefore, it is important to select an adequate printing substrate for each printing technique. Awareness of environmental problems related to the shortage of wood raw materials has led to an increase in the use of recycled printing paper and in particular the implementation of new alternative sources of cellulose fibres instead of virgin wood fibres in the papermaking process. In this research the emphasis is precisely on defining the influence of ink penetration into laboratory papers made of triticale pulp on the final print quality. The laboratory printing papers were obtained by mixing triticale pulp with pulp from recycled fibres in three different portions. Papers were thereafter printed by ultraviolet (UV) inkjet printer and the ink penetration within laboratory papers with and without straw pulp was analysed using two methods of ink penetration analysis (microscopic/spectroscopic). The influence of ink penetration on the final print quality was observed and analysed based on several quality parameters (optical ink density, mottling and colorimetric values). These results confirmed that triticale pulp in laboratory papers provides equal print quality compared to laboratory papers made only from pulp from recycled fibres.
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Due to the rising problem of deforestation, slow renewability, and higher cost of wood sources, it is of great importance for the paper and packaging industry to find suitable, environmentally ...friendly alternative sources of cellulose fibers. Much of the research has focused on studying the use of non-wood sources from various annual or perennial plants from which cellulose fibers can be obtained with equal quality to those from wood sources, since they are a fast-growing, renewable, and cheap source of fibers. This research focuses on the laboratory production and stability valorization of a paper substrate for packaging containing virgin fibers from triticale straw mixed with recycled wood pulp in various amounts up to 30%, printed with black ink through a simulation of the offset printing technique under controlled conditions. For stability analysis, printed paper substrates were subjected to three treatments essential for packaging: aging, rubbing, and chemical treatment. The stability of the prints was evaluated after treatments though spectrophotometric measurements (ΔE*ab, ΔR, ΔL*, Δa*, Δb*) and Fourier transform infrared analysis. The aging, rubbing, and chemical stability of the prints with the addition of triticale virgin fibers was improved for all product packaging except for products containing soybean oil.
Today, the paper industry is faced with a global deficiency of raw wood materials, so alternative sources of virgin cellulose fibres are playing an important role in paper production. Agricultural ...countries produce large quantities of crop farming by-products such as straw, which is an interesting alternative raw material for cellulose fibres. Straw is used in many industries because of its numerous advantages: animal food industry, biofuel industry, construction industry and as artistic material. The potential use of straw production residues is of great importance in paper and printing industry. The focus of this research is on triticale straw, which was used as a non-wood fibre source for paper production. Namely, triticale straw was converted into semi-chemical pulp and was combined with recycled wood pulp in order to produce alternative laboratory papers. The usability of this kind of laboratory papers in printing industry was analysed based on line reproduction quality. This research evaluated and analysed line reproduction quality based on four line attributes: width, blurriness and raggedness. The results of this research proved that triticale pulp in laboratory papers has equal influence on line printing quality as the recycled wood pulp.
Wood is still the most widely used raw material for pulp and paper production in the world. However, due to the necessity to supply the paper industry with raw materials used in the extraction of ...cellulose fibres and the overexploitation of forests, new sources of primary pulp fibres had to be identified. The aim of this research is to highlight the important features of cereal crop residues and their utilization in the paper industry. As the chemical composition of plant materials is one of the most important indicators of how such materials can be used in paper production, the analysis of the chemical composition of straw with the highest grain production was performed. The straw, as a harvesting residue, is a fibre resource available from the annually renewable crops, produced abundantly in numerous regions all over the world. For the purpose of the research, wheat, triticale and barley straw were selected for the analysis. The analysis of carbohydrate, lignin and extraneous material (organic extractives and inorganic minerals) was performed in order to obtain the straw chemical composition. Based on the results of the chemical composition of all analysed straw, it was confi rmed that straw, as an agricultural by-product, is rich in cellulosic fibres and, therefore, a valuable raw material for the paper industry. Out of all analysed straw, based on the results of their chemical composition, triticale straw is considered potentially the best source of alternative cellulose fibres.
This paper describes the improved removal of impurities (coating, ink/toner) from offset prints produced by digital printing of two-side coated paper. The substrates were printed by conventional and ...digital offset processes. Based on image analysis results it was established that deinking flotation is an inefficient method for ink particle removal from digital offset printed paper, but it is efficient for ink removal from conventional offset printed paper. On the other hand, pre-treatment with hydrogen peroxide solution gives better results for ink particle removal from digital offset prints than from conventional offset prints. Optimal parameters for hydrogen peroxide pre-treatment for both offset prints were chosen based on unprinted substrate mass loss results in the preliminary investigation. These results showed that hydrogen peroxide pre-treatment is more successful at removal of impurities in comparison with flotation deinking without pre-treatment.
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In recent years, due to environmental awareness regarding the harmfulness of polymeric materials, there has been a growing interest in using papers, especially those from alternative raw materials. ...The importance of using all available raw materials is imperative today. Raw materials that were once viewed as waste are now of great importance because they have the ability to replace raw materials that are used irrationally or are lacking. Cereal straw is a lignocellulosic material that could be used in the paper industry and in the production of increasingly prevalent paper packaging. The aim of this research was to analyze the relationships between the qualitative parameters of straw-based printed papers containing 30% agricultural residues (wheat, barley, or triticale). The influence of two qualitative parameters (ink penetration depth and optical ink density) on the print-through was observed using multiple regression analysis on straw-based papers produced at the laboratory level. Throughout the research, 100% recycled wood paper was used as a reference sample. The results of the regression analysis showed that none of the variables individually make a statistically significant contribution to the prediction of the dependent variable in a linear context, that is, they indicate a non-linear interaction between the variables and the specific conditions under which the dependent variable reaches local extremes and changes in the gradient. Considering the results of the regression analysis and the visualization of the relationship, the model was additionally tested with other independent variables (paper type). From the results obtained, it can be concluded that the alternative straw-based paper with 30% barley pulp has the best interaction between ink and paper, which is the most similar to the reference sample in terms of printability, while the alternative straw-based paper with 30% wheat generally differs significantly from the reference paper when all three prints are considered.
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