Papers by Edyta Małachowska
Energies, Jul 31, 2019
The results of enzymatic hydrolysis of birch and beech kraft cellulosic pulps indicate that they ... more The results of enzymatic hydrolysis of birch and beech kraft cellulosic pulps indicate that they may be promising feedstocks for fermentation processes including biofuel manufacturing. The aim of this study was to investigate whether birch and beech wood require the same degree of delignification by kraft pulping as pine wood. The differences observed in the efficiency of hydrolysis for the raw materials tested suggest that the differences in the anatomical structure of the examined wood in relation to pine wood is essential for the efficiency of the enzymatic hydrolysis process. The yields of glucose and other reducing sugars obtained from the birch and beech cellulosic pulps were similar (up to around 75% and 98.3% dry weight, and 76% and 98.6% dry weight, respectively). The highest glucose yields from cellulose contained in the birch and beech pulp were around 81.2% (at a Kappa number of 28.3) and 83.1% (at a Kappa number of 30.4), respectively. The maximum glucose yields and total reducing sugars of birch wood on a dry weight basis (39.8% and 52.1%, respectively) were derived from the pulp at a Kappa number of 28.3, while the highest yields of glucose and total reducing sugars of beech wood on a dry weight basis (around 36.9% and 48.2%, respectively) were reached from the pulp at a Kappa number of 25.3. To obtain the highest glucose yields and total reducing sugars of a wood on a dry weight basis, total lignin elimination from the birch and beech pulps was not necessary. However more in-depth delignification of birch and beech wood is required than for pine wood.
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology, 2015
The paper presents tensile properties of paper produced from mixure of poplar and pine cellulosic... more The paper presents tensile properties of paper produced from mixure of poplar and pine cellulosic pulps. Pine cellulosic pulp was delivered by one of domestic paper mills and is mainly used for production of fine graphic paper. Poplar pulp was produced at Institute of Papermaking and Printing. The produced paper was thoroughly investigated and structural, tensile and optical properties were measured. This work presents just the most crucial properties like breaking length and tear resistance.
Coatings
Despite numerous methods to optimise their operation and parameters, anilox rolls are subject to ... more Despite numerous methods to optimise their operation and parameters, anilox rolls are subject to rapid wear during use and due to improper cleaning processes. Therefore, regular diagnosis is needed. In this study, X-ray fluorescence (XRF) analysis based on Fe and Cr was used to determine the elemental compositions of raster cylinder coatings. Due to the layered composition of the anilox roll, where Cr2O3 coating is applied on the iron core, evaluation of the composition of the roll surface can be used to detection of anilox damage. A portable XRF apparatus was used to identify selected elements even at low concentrations of <1%. In this work, it was proved that XRF can be a preliminary, rapid method for assessing the technical condition of an anilox cylinder. The XRF technique can be safely used in non-destructive chemical analyses of the anilox rollers’ condition in flexographic printing technology, and chemical information that aids in their use may be routinely obtained, thus ...
Sustainability
The properties of the fibers determine the quality of the pulp and, thus, the quality of the pape... more The properties of the fibers determine the quality of the pulp and, thus, the quality of the paper made from it. Recognition of properties, which fiber and paper pulp should be characterized by, in order to achieve required paper properties, is, therefore, a subject of research and interest of many papermaking research experts and scientists. Fibers are subject to deformation and possible weakening under the influence of chemical and mechanical factors, and therefore the quality of the fibers decreases each time they are used in production when it comes to recycled pulps. Then again, the key factor determining the quality of the primary fiber is the degree of pulp delignification. In the article, an attempt was made to define the impact of delignification of virgin pulp on morphological properties of fibers, and compare them with the properties of recycled paper pulp, in order to find correlations. The current economic and raw material situations in the wood market force one to seek...
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology, 2015
Influence of temperature on Bendtsen air permeability. This work presents the impact of drying te... more Influence of temperature on Bendtsen air permeability. This work presents the impact of drying temperature and drying time on the air permeability properties of Bendtsen method on the final product. With the obtained results show that the air-dry pulp has a higher values of air permeability of the dried pulp. Furthermore, it shows that by drying the pulp occurs hornification and flexibility of fibre had been declining. However, even as a result of the refining process original features of fibre can not obtain the retained.
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology, 2015
Selection of enzymes for pulp refining. The goal of this research is to investigate the impact of... more Selection of enzymes for pulp refining. The goal of this research is to investigate the impact of enzymatic pre-treatment on pulp refining and provide guidelines for selection of enzymes enhancing refining process. For this purpose commercially available enzymes and enzyme preparations were used. This topic is very important because pulp refining process is very expensive and consumes about 50% of all electrical energy used in the process of paper manufacturing. Application of suitable enzymes may contribute significantly to reduction of energy consumption in paper production process.
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology, 2015
Comparison of papermaking potential of wood and hemp cellulose pulps. The use of fibre hemp (Cann... more Comparison of papermaking potential of wood and hemp cellulose pulps. The use of fibre hemp (Cannabis sativa L.) for pulp and paper dates back more than 2,000 years. This technology disappeared, but we have a significant reasons to try to reproduce and improve this technology. The aim of this paper is to present experimental researches, which show that hemp can be successfully used in paper industry and replace wood. This work presents the pulp and paper properties obtained from wood and hemp cellulose pulps. To comply studies were used refined and unrefined pulps. In order to digestion of the raw material used sulfate method, which is the dominant process of digestion in worldwide scale 80%.
Sustainability
In the 21st century, numerous economic and environmental initiatives have significantly increased... more In the 21st century, numerous economic and environmental initiatives have significantly increased paper recycling, which continues to expand due to environmental awareness. With increasing recycling rate, low-quality paper fractions may be included in the process, leading to the overproduction of very low-value papers that cannot be reprocessed. Moreover, the production of paper from poor-quality wastepaper can result in the introduction of chemicals from the recycled paper into the recycling loop and unintended spread of chemical substances. Therefore, reliable and conscious selection of recycled pulp is imperative. To this end, the present study verified the properties of recycled pulp critical for the assessment of its papermaking ability for the production of high-quality sanitary paper. Following an examination of samples, it was found that the key parameters that influence the papermaking ability of wastepaper include presence of impurities, content of extractive substances, f...
Bioresources, 2019
Refining is a primary unit operation that has a large impact on the quality of paper products and... more Refining is a primary unit operation that has a large impact on the quality of paper products and cost of production. The refining process of cellulose fibers is the most energy-intensive step in the preparation of paper pulp. High energy consumption during the refining process has motivated researchers to improve the economics of the process without decreasing the strength of the paper produced. This objective can be realized through easily refined pulps that are produced from alternative vegetal fibrous raw materials. This work compares the energy consumption of refining soft, hardwood, and fast-growing fibrous materials to 30 °SR. The goal was to reduce energy consumption while maintaining the strength properties of the paper received. For this purpose, cellulose pulps from fast growing plants including poplar, larch, and grasses were used.
Materials, methods & technologies, 2016
This article presents the impact of laboratory refiner load on papermaking potential of paper. Bl... more This article presents the impact of laboratory refiner load on papermaking potential of paper. Bleached pinewood kraft pulp from one of paper mills was used for the investigation. The main goal of the work was to investigate the influence of refiner load on properties of paper. According to scientific literature it is assumed that lower refiner load enable to obtain paper of high tensile properties but requires longer refining time. This concept was investigated in this work. Cellulosic pulp was refined in Valley beater and after refining properties of both pulp and paper were investigated. The obtained results have led to conclusions that there is a minimal refining load which is necessary produce paper with sufficient tensile properties. Moreover, observed differences in paper properties for different refining load after exceeding this minimal value are not very significant. Furthermore, detailed characteristics of paper refined using different load from 1,361 kG up to 8,165 kG ar...
Influence of coating grammage on the utility properties of coated papers.The paper coating offers... more Influence of coating grammage on the utility properties of coated papers.The paper coating offers the opportunity to create a product with high added value, the potential of which has been recognized by both paper mills and polygraphs.Indeed, paraffin coatings have excellent barrier, sliding and strength properties, and also increase the quality and durability of the print. This paper presents the results of the research on the influence of the coating weight on the functional properties of the coated paper. To this end, a commercially available paper was coated with a paraffin emulsion using various Mayer rods and then tested using standard mechanical, surface, and water absorption tests. It was found that the coating of the base paper, regardless of the amount of the applied mixture, significantly influences its hydrophobic, surface, and strength properties. Papers with the highest coating weight allowed to obtain a paper with increased strength and high surface smoothing. The com...
The results of enzymatic hydrolysis of birch and beech kraft cellulosic pulps indicate that they ... more The results of enzymatic hydrolysis of birch and beech kraft cellulosic pulps indicate that they may be promising feedstocks for fermentation processes including biofuel manufacturing. The aim of this study was to investigate whether birch and beech wood require the same degree of delignification by kraft pulping as pine wood. The differences observed in the efficiency of hydrolysis for the raw materials tested suggest that the differences in the anatomical structure of the examined wood in relation to pine wood is essential for the efficiency of the enzymatic hydrolysis process. The yields of glucose and other reducing sugars obtained from the birch and beech cellulosic pulps were similar (up to around 75% and 98.3% dry weight, and 76% and 98.6% dry weight, respectively). The highest glucose yields from cellulose contained in the birch and beech pulp were around 81.2% (at a Kappa number of 28.3) and 83.1% (at a Kappa number of 30.4), respectively. The maximum glucose yields and tot...
The utility properties of paper are dependent on the modification of the structure of the cellulo... more The utility properties of paper are dependent on the modification of the structure of the cellulose fibers, which is achieved via refining. The most important outcomes of the refining process are changes in the internal fibrillation and the shortening of the cellulose fibers. There are numerous opinions published in literature describing the relationship of these parameters and their impact on the final paper properties. These publications have been primarily based on the results of measurements conducted using insufficiently precise methods and simple speculations. The authors of this work decided to determine the effect of the refining intensity on the progress of internal fibrillation and shortening of cellulose fibers and the interrelation between these effects. Refining was performed with a laboratory Hollander beater, which was able to apply different refining loads. Utilizing additional control equipment, the specific edge load was also calculated. Finally, the impact of the ...
Effect of refiner load on Bendtsen air permeability. The main aim of this paper is to compare the... more Effect of refiner load on Bendtsen air permeability. The main aim of this paper is to compare the impact of refiner load, on Bendtsen air permeability of paper sheets. This article assesses changes of air permeability of paper sheets obtained from pulp refined at different intensity. Results show that refiner load plays an important role in refining process, since it affects both the energy consumption of this process and improve various properties of paper. All of results allowed to present significant impact of refining process to develop papermaking ability of
This article presents the impact of a degree of polymerization on the papermaking potential of pa... more This article presents the impact of a degree of polymerization on the papermaking potential of paper. Bleached pinewood kraft pulp from one of paper mills was used for research purposes. The main objective of this work was to investigate the influence of a degree of polymerisation of pulp on the properties of fibres such as water retention value (WRV) and the fines content etc. Different degrees of polymerization were obtained as a result of the pulp drying at different temperatures (105 ̊C, 130 ̊C and 150 ̊C) for a period from 1 hour up to 150 hours. During the drying process, a visible decrease in a degree of polymerization of cellulose in hornified fibres occurs. Significant differences in pulp properties can be observed in particular in case of pulps dried at a very high temperature (150°C) and in case of a long drying time (150 h).
The degradation of cellulose is an important factor influencing its mechanical, optical, physical... more The degradation of cellulose is an important factor influencing its mechanical, optical, physical, and chemical properties and, hence, the lifetime of paper in libraries and archival collections. Regardless of the complexity of the paper material, the main chemical pathways for its degradation are hydrolysis and oxidation. This study presents an overview of the analytical techniques employed in the evaluation of the hydrolysis and oxidation processes; these techniques include size-exclusion chromatography, Fourier-transform infrared and ultraviolet–visible spectroscopy, and X-ray diffraction. This paper aims to determine the extent to which these instrumental methods are useful for studying the aforementioned processes and for which lignin contents. It also highlights how atmospheric humidity could affect the cellulose structure in paper containing lignin. It was found that humidity causes significant changes in the cellulose chain lengths and that a high lignin content in paper cou...
Molecules
Petroleum, synthetic, and natural waxes have been used as hydrophobic bases for dispersions inten... more Petroleum, synthetic, and natural waxes have been used as hydrophobic bases for dispersions intended for use as barrier coatings for packaging paper. Oil-in-water dispersions with alkaline pH were prepared by a two-step homogenization procedure containing paraffin wax, with various characteristics, the Fischer–Tropsch synthesis product or beeswax. The size of the dispersed particles determined by dynamic light scattering depended on the type of hydrophobic base used and was in the range of 350–440 nm. The ability of dispersion particles in aggregation driven by electrostatic attraction, evaluated by Zeta potential analysis by electrophoretic light scattering, was from −26 to −50 mV. Static multiply light scattering was used for 30 days of stability assessment and helped to select the dispersion with a Sarawax SX70 wax base as the most stable. Dispersions were further used for coating the backing of kraft paper by the Meyer rod method. Coated paper with an applied coating of 6 g/m2 h...
Paper degradation menaces the useful lifetime of books, manuscripts, and works on paper during st... more Paper degradation menaces the useful lifetime of books, manuscripts, and works on paper during storage, circulation, and display in libraries, archives, and museums. Severe damages such as embrittlement, decay, and mold often occur to the paper that might threaten to lose cultural heritage. However, the shelf life of papers stored in suitable conditions can be extended by hundreds of years. The most important external factors affecting the deterioration of paper-based materials include, in particular, changes in temperature and air humidity. In this study, the effects of accelerated aging under different conditions, including substantially different relative humidity, were considered relative to the strength properties of the paper sheets. These include the mechanical strength, such as breaking length, tear resistance, and bursting strength of the paper samples before and after dry heat aging and hydrothermal aging. Samples with various content of lignin produced in neutral pH were ...
Scientific Reports
Paper degradation on a macroscopic scale is characterised primarily by yellowing, an increase in ... more Paper degradation on a macroscopic scale is characterised primarily by yellowing, an increase in brittleness, and other destructive changes caused by the hydrolysis of glycoside bonds and oxidation reactions. Until now, lignin has been believed to cause these changes. However, contemporary analysis has not confirmed this assumption and has attributed low paper resistance to ageing with acidification owing to the production in acid environments that involve aluminium sulfate. In view of the common belief this manuscript presents studies on the accelerated ageing of papers with different lignin contents that are produced in neutral environments. To achieve the objective, artificially aged papers under conditions of increased humidity and temperature were investigated using chromatographic (SEC) and spectroscopic (FTIR and UV–Vis spectroscopy) techniques. Mechanical tests were used to determine the decrease in tensile properties of the samples. We observed no effects of the lignin cont...
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Papers by Edyta Małachowska