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The use of mineral-based fillers tends to reduce the mechanical properties of paper, which can limit their application. The filler surface modification is a significant treatment to overcome this limitation. This research aims to offer a novel modified mineral-based filler to provide its industrial application. The surface of precipitated calcium carbonate (PCC) was modified with xylan (XS), which is a type of hemicellulose, a polysaccharide consisting mainly of xylose residues. It is used as a filler at different filler dosage levels in paper pulp. Modified PCC(MPCC) was characterized with Fourier transform infrared spectroscopy, Thermogravimetric analysis, X-ray photoelectron spectroscopy, X-ray diffraction and Field-emission scanning electron microscopy analyses. The analysis demonstrated that the MPCC filler surface was coated with XS successfully. The effect of PCC and MPCC-filled hand-sheet paper physical, chemical and optical properties were studied. The experimental results showed that the mechanical (tensile, burst, tear strength) and optical (brightness, opacity) of hand-sheet paper filled with MPCC were significantly improved compared with unmodified PCC-filled paper at the same ash content. The filler retention of PCC and MPCC fillers in paper was investigated, and the MPCC filler showed better filler retention properties in paper stock than the PCC filler. [ABSTRACT FROM AUTHOR]

This research investigated the influence of the layered structure of paper on its selected strength properties. Two types of cellulose pulp were used: unbleached kraft pine pulp (UBSK) and unrefined bleached birch kraft pulp (BHK). Multi-ply papers were obtained from layers of appropriate grammage formed separately and bonded in a wet state. Paper layers were formed from primary pulps (UBSK and BHK) or their mixtures (threeply UBSK-BHK paper and three-ply UBSK-BHK-UBSK paper), from which various variants of laboratory paper samples were made. This work focused on three-layer papers. The obtained laboratory sheets were analysed for changes in tear resistance, tensile strength, bursting strength, short span compression strength (SCT), and corrugating medium test (CMT). In most cases, three-layer structures were characterised by higher strength parameters than single-layer papers. The tear strength and SCT of papers consisting of three layers formed from both mixed pulps were slightly lower than those of solid papers. The results demonstrate the feasibility of producing three-ply paper with significantly reduced variability in parameters such as elongation and bursting strength, which are inherently subject to high variability. [ABSTRACT FROM AUTHOR]

Phosphorylated fibers offer a broad range of applications, particularly in thermal insulation, notably with wood fibers, provided they exhibit improved mechanical characteristics. Despite encountering challenges in applying traditional papermaking methods, the creation of paper or board sheets with phosphorylated pulp fibers remains a challenge. Findings suggest that phosphorylation-modified fibers show increased roughness. Moreover, in comparison with unbeaten kraft sheets (KF) and thermomechanical pulp sheets (TMP), those made from phosphorylated kraft fibers (PKF), using a cationic coagulant and a flocculant, demonstrate significant enhancements in burst index, break index, and tensile energy absorption by 2.12 times, 1.7 times, and 2.77 times, respectively. Similarly, phosphorylated TMP sheets, prepared with a dual polymeric system (coagulant/flocculant), exhibit improvements of 1.42 times, 1.33 times, and 1.82 times, respectively, in these properties. The study emphasizes the ameliorating effect of cationic polymeric agents on the charge impact of phosphorylated fibers on overall sheet quality, while also highlighting the substantial influence of hot-pressing lignin-containing paper on all determined physical properties. [ABSTRACT FROM AUTHOR]

Paper, which is in fact a very complex cellulose-based product derived from different lignocellulosic resources, is usually regarded as a simple omnipresent commodity in our lives. Wood fibers derived from trees are the most employed sources for papermaking purposes. From an environmental protection perspective, and for their essential role in our life (they give us the life itself through their foliar system supporting the photosynthesis process), trees should not be extensively cut down and they should be used less and less for papermaking. Thus, employment of non-woody alternative sources for papermaking could be exploited more as an attractive and feasible option.

Paper, which is in fact a very complex cellulose-based product derived from different lignocellulosic resources, is usually regarded as a simple omnipresent commodity in our lives. Wood fibers derived from trees are the most employed sources for papermaking purposes. From an environmental protection perspective, and for their essential role in our life (they give us the life itself through their foliar system supporting the photosynthesis process), trees should not be extensively cut down and they should be used less and less for papermaking. Thus, employment of non-woody alternative sources for papermaking could be exploited more as an attractive and feasible option. [ABSTRACT FROM AUTHOR]

This article traces the history of the relationship of papermaking and paper to libraries over time. Paper was first made in China and is traditionally considered one of that nation's four greatest inventions, along with gun powder, printing, and the compass. Papermaking was often associated with archives in its early development in China, as well as when it was introduced to Japan, where it came to be a part of some Shinto and Buddhist temples, and later governmental agencies. Under Islam, the availability of paper was linked to increased literacy and growth of libraries. In early modern Europe, before the widespread use of wood in the papermaking process, libraries and archives were part of an "economy of paper" with paper at times being in short supply. In the modern era, the world of papermaking did not intersect much with the world of the library, which made progress with the problem of brittle books, one of its greatest challenges, slow, though recent efforts of government, industry, scientists, and representatives of the library have produced positive results. The damage caused by wood-based paper in libraries was mirrored by the environmental damage caused by wood-based papermaking in communities. The history of papermaking and libraries demonstrates the importance of understanding the technologies which support the library, while also advocating effectively to the representatives of all its sources of support in ways which promote the values of the library and its associated community. [ABSTRACT FROM AUTHOR]

In this article paper, leather from book cover and metal lock from an 18th century church book were studied. The book was printed during the time of Mihai Constantin Șuțu, with the blessing of the Metropolitan of Moldova, Iacov Stamati. The analytical method used to study the components and the methods of obtaining all the important parts was the non-destructive technique SEM-EDX. The results regarding the used paper showed typical intermeshed cellulose fibers. In the case of leather, due to its advanced state of degradation, it was impossible to determine the type of animal from which the skin was used. The elemental analyses (EDX) of the metal lock indicated that it was made of brass. The results of the study of 18th century parts of the book, gave important information about the way of paper manufacture, the conservation state of the cover and the way that the metal lock was made and the safe way to clean it in the restoration and conservation process. [ABSTRACT FROM AUTHOR]

This progress report details the imaging and initial analysis of watermarks and countermarks present in antique, laid paper leaves from a partial, disbound blank book in the study collection of the Conservation Center at the Institute of Fine Arts at NYU. Preliminary review of watermark catalogues indicates that the paper, featuring the coat-of-arms of Le Tellier of three stars over three lizards, and a countermark reading "H. J. Cusson," dates roughly from the late seventeenth to early eighteenth centuries. Of the approximately 115 sheets, 20 were analysed using software developed by William A. Sethares (University of Wisconsin, Madison) and C. Richard Johnson, Jr. (Cornell University) to reliably predict whether individual papers were likely to have been made by the same papermaking mold. The programs allowed for the comparison of watermark and countermark shapes by comparison of the ratios of their internal proportions (WatermarkMarker), and the generation of animated overlay.gifs that fade from one image to the next, for instant visual comparison (WatermarkPointMarker and VisualizeOverlays). The incidence of watermarks and moldmates in the folios were also mapped using the VisCodex online collation visualization tool, developed by the University of Toronto Libraries, in collaboration with Dot Porter and Alberto Campagnolo. The results suggest that the stack of sheets was made from two papermaking molds, making the papers moldmates and twins. The progress report concludes with a hypothesis as to which watermark was connected to which countermark, and suggests that the connections between half-sheets may be more easily recreated after more sheets have been analyzed both visually, and with the software. [ABSTRACT FROM AUTHOR]

This article focuses on the professional writing of women in the transformation phase around 1800. Referring specifically to the woman of letters Helmina von Chézy (1783-1856) and her family, which participated in the literary market over four generations, it asks how authors could use paper(s) as assets or resources. It is shown that writersʼ papers were collected and kept as material evidence of life, that they could be an indicator of financial status and provide insight into financial practices, and that they were used particularly to position oneself (as a writer) and to relate to others. Within changing personal and historical contexts, the writing work of family members was based ultimately, in varying forms and shapes, on the logics of their social relations, lived as well as negotiated and recorded on paper. Thus, the papers used and inscribed in the family can be conceptualized as a multi-perspective kaleidoscope, offering new views on central aspects and mechanisms of writerly economies. [ABSTRACT FROM AUTHOR]

This article analyses the importance of paper in the context of early modern warfare. During the war against the Ottoman Empire at the end of the 17th century, the Habsburgs were establishing a new administration in Hungary, which served both military and civil purposes. Not only did administrative tasks have to be organized, but the very success of military operations depended on the well-ordered work of the administration: communication had to be smooth, and a wide variety of tasks had to be properly and reliably processed. To fulfil these requirements, the administration needed large quantities of paper. This study follows the traces of paper in the records of the Chamber Administration in Buda and points to the vital need for paper at the heart of the new Habsburg rule. The challenges of acquiring and producing paper themselves became crucial aspects of the administration’s work. The article argues that a reliable supply of paper competed even with the distribution of arms and food to become an essential resource in warfare. [ABSTRACT FROM AUTHOR]

Paper was already being used in southwestern Germany before the first paper mills began production there in the late 14th century. But it was the establishment of a local paper industry that made the still relatively new writing material available in large quantities. The demand for paper made the operation of a paper mill seem profitable, and the increased supply of paper in turn fueled the rise in writing. At the end of the Middle Ages, paper thus became the material basis of a media evolution that extended far into modern times. But how was the new writing material produced? The new craft of papermaking differed significantly from the production of parchment, the traditional writing material, in terms of equipment, raw materials, capital requirements, and working methods. Nevertheless, papermaking could use already existing infrastructures, especially in the field of energy supply by waterwheels. This article examines the specific characteristics of the new craft using the example of the German southwest, where numerous paper mills were established in the 15th century. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Al-Frahids Arts is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Although they are pegged to receive, emergencies occur with some frequency and sometimes cannot be "predicted" or even when emergency situations occur they become crucial and can save an organization from a harmful disbursement. However, most urgent purchases are oriented toward the low or inexistent planning, which, in addition to the economic factor in increasing the value of the good or the service, affects the areas involved, and even the image of the organization, the environmental and safety factors. Thus, the cause of emergencies becomes an indication and the negotiations can mean reduction of millions in expenses of large industries. Thus, the study became systemic in the emergency purchases of a large Brazilian pulp and paper producer, in addition, a methodology that allowed the reduction of planting and application costs. As a result, the goal of a 10% reduction in emerging expenditures in 2018 when compared to the previous year. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, different methods for incorporating mixed or laminar copper microparticles (CuMPs) during papermaking were evaluated to determine the optimum paper-making process and correlate particle concentration and shape with antimicrobial activity. The addition of CuMPs during the disintegration of dry pulp stage was observed to produce a paper with uniformly distributed CuMPs, as determined through optical microscopy and UV–Vis spectroscopy analyses by measuring absorbance spectra in different areas of papers. Determination of two indices related to the concentration and distribution of copper will allow to predict the copper content in other papers. CuMP-paper samples were evaluated for structural, optical, and mechanical strength properties according to paper industry standards. Quantitative analyses by atomic absorption showed that between 24 and 39% of CuMPs were embedded in the paper fibre, independent of particle type. Finally, antibacterial activity analyses were performed according to ISO 20645 and ISO 20743. The results showed that papers with 0.30 g of incorporated CuMPs have antimicrobial activity, independent of particle morphology, with effects observed towards Gram (+) and Gram (−) bacteria and fungus. Furthermore, the evaluation of antimicrobial activity at different times of exposure to the microorganisms showed differences in effects that were dependent on the shape of the CuMPs incorporated into paper, where laminar particles exerted a sufficient effect, while no or a slight effect was observed for mixed CuMPs against Aspergillus niger. [ABSTRACT FROM AUTHOR]

Xylan is primarily found in the secondary cell wall of plants providing strength and integrity. To take advantage of the reinforcing effect of xylan in papermaking, it is crucial to understand its role in pulp fibers, as it undergoes substantial changes during pulping. However, the contributions of xylan that is added afterwards (extrinsic) and xylan present after pulping (intrinsic) remain largely unexplored. Here, we partially degraded xylan from refined bleached softwood kraft pulp (BSKP) and adsorbed xylan onto BSKP. Enzymatic degradation of 1 % xylan resulted in an open hand sheet structure, while adsorption of 3 % xylan created a denser fiber network. The mechanical properties improved with adsorbed xylan, but decreased more significantly after enzymatic treatment. We propose that the enhancement in mechanical properties by adsorbed extrinsic xylan is due to increased fiber-fiber bonds and sheet density, while the deterioration in mechanical properties of the enzyme treated pulp is caused by the opposite effect. These findings suggest that xylan is decisive for fiber network strength. However, intrinsic xylan is more critical, and the same properties cannot be achieved by readsorbing xylan onto the fibers. Therefore, pulping parameters should be selected to preserve intrinsic xylan within the fibers to maintain paper strength. [Display omitted] [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bacterial nanocellulose (BNC) is a unique natural nanomaterial that shares very few similarities with other natural or industrially produced nanomaterials. BNC can be produced by a variety of bacteria, as a survival aid in different ecological niches. BNC is traditionally produced by static or shaking culture methods, and the 'mother vinegar', or biofilm, is a typical example of this product after static vinegar fermentation. BNC has great potential in biomedicine, and recent studies have also demonstrated its use in the papermaking industry. It has nanoscale fiber size and large numbers of free hydroxyl groups, which ensure high inter-fiber hydrogen bonding. Thus, BNC has great potential as a reinforcing material, and is especially applicable for recycled paper and for paper made of nonwoody cellulose fiber. As well as enhancing the strength and durability of paper, modified BNC shows great potential for production of fire resistant and specialized papers. However, the biotechnological aspects of BNC need to be improved to minimize the cost of its production, and to thus make this process economically feasible. [ABSTRACT FROM AUTHOR]

Generated in the pulp and paper production process, cellulosic pulp fines are fibrous cellulosic materials capable of passing a 200 mesh screen. Processed pulp fines remain in the pulp and affect pulp and paper sheet properties. Their specific morphology promotes interactions with fibers and alters sheet properties. Nevertheless, the 3D distribution of fines in paper sheets has not been revealed so far. Localizing fines within a matrix of fibers is challenging since both elements have the same chemical composition and fines have small dimensions. It is required to increase the contrast of pulp fines, while avoiding any alteration of initial fines morphology. In this study, fines were first separated and labeled with Rhodamine B isothiocyanate, a fluorescent dye. Labeled fines were blended with pulp at different concentrations and paper sheets were produced from each mixture. Prior to imaging, pulps and handsheets were characterized by standard pulp and paper tests and compared with references, showing no significant differences between sheets containing labeled and untreated fines. Thus, mechanical and physical tests indicated that no, or only minor alteration of fines properties by the labeling process occurred. We then applied two imaging techniques to detect the labeled pulp fines in the paper network, namely confocal laser scanning microscopy and multiphoton microscopy, visualizing the 3D distribution of fluorescent fines within the fiber network. The results obtained also allowed a differentiation between morphologically different fines showing fiber fragments more attached to single fibers whereas more fibrillar fines concentrate in fiber–fiber joints, thereby strengthening bonding. [ABSTRACT FROM AUTHOR]

Wood is versatile, inexhaustible and renewable. These made the wood an outstanding material used in different domain such as raw material for production of pulp, paper and fibre based products. In Nigeria, one of the problems in pulp and paper industry is inadequate supply of long fibre for paper production. Also, overexploitation of materials having desirable fibre characteristic was observed. Therefore, there is need to research into lesser known wood species so as to ascertain its suitability for paper making. This study presents the potential of Aningeria robusta wood as source for adequate fibres for paper making. Samples of 20x20x20mm were collected from the three trees of Aningeria robusta wood at different position; base (10%), middle (50%) and top (90%) along the merchantable height and prepared into slivers of 3mmx10mm for examination of the fibre characteristics. Thereafter, it was macerated and viewed under microscope. Further morphological indices were calculate accordingly. The mean fibre length, fibre diameter, lumen, cell wall thickness (CWT), slenderness, flexural ratio and runkel ratio were 1.55mm, 11.71µm, 8.78µm, 1.46, 132.12, and 75.07 respectively. Variation of indices along sampling heights were not significant except for CWT. A. robusta has shown good properties and could be added to already known wood species suitable for paper making. [ABSTRACT FROM AUTHOR]

This serves as report on a second in a series of train-the-trainer workshops held in March 2019 by the South African Museums Association to improve heritage preservation skills in South African institutions, which focused on the care and repair of paper-based objects in heritage collections. Paper-based objects are very common in heritage collections, often hiding in plain sight due to the contemporary ubiquity of paper. They may take the form of institutional records, or support non-text formats such as photographic prints. Paper-based objects will form part of most museums' preservation responsibilities, making a working understanding of the preservation challenges to paper-based collections an essential component of any museum's institutional preservation activities: having a working understanding of paper, its preservation challenges and care is essential for heritage intuitions. The workshop was held at the Western Cape Archives and Records Service (Cape Town), South Africa's oldest and second-largest government archive. The Archive holds an extensive collection of book and paper documents, estimated at some 45 linear kilometres of shelved records that documents the settlement and colonisation of South Africa. The workshop made use of the Archives' records collection to teach the workshop participants about the history and development of papermaking and bookmaking within the context of South African institutional collections. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Information is provided on the properties of technical-purpose papers based on heat-resistant superhigh modulus (SHM) para-aramid fibres containing heterocyclic rings. Various methods of producing such papers are reviewed. The properties of samples of the heat-resistant papers are listed. The results of study and comparison of chemical resistance of the obtained papers are adduced. [ABSTRACT FROM AUTHOR]

Starch-coated paper is widely used in packaging, printing, writing, and so on. However, achieving starch-coated paper with excellent moisture resistance remains a challenge for its end uses. To overcome this challenge, we hypothesize that the film-forming ability of starch plays a pivotal role in the moisture resistance of starch-coated paper. Polyvinyl alcohol (PVA) is used to enhance the film-forming capability of starch film and the moisture resistance of PVA/CS coated paper is evaluated in terms of moisture absorption, tensile index, and stiffness. A PVA/CS film with only a coating weight of 4.0 g/m 2 can fully cover the porous structure of paper that leads to a higher moisture resistance than CS-coated paper with a similar loading weight. However, as the coating weight continues to increase, the decline of the mechanical properties of PVA/CS coated paper is almost unchanged. Furthermore, the moisture resistance of PVA/CS coated paper (coating weight is larger than 4.0 g/m 2 ) is further improved by using glyoxal as moisture proof agent (MPA). Only 4.8% and 6.3% losses in the tensile index and stiffness at a coating weight of 4.0 g/m 2 are achieved before and after moisture treatment, respectively. These results may shed light on exploring new method to enhance moisture resistance of starch-coated paper. [ABSTRACT FROM AUTHOR]

This paper reviews key advances in understanding the hydrodynamics of the forming section of papermaking during the years 1950 to 2000. Over this period papermaking advanced from rather slow-speed Fourdrinier machines to modern high-speed twin-wire formers. The advances are described in the context of technical problems faced at the time to increase machine speeds and improve paper properties. The scientific work and advances in machine design contributed greatly to the marvel of modern papermaking, which now includes machines 10 m wide operating at speeds over 100 km/h. [ABSTRACT FROM AUTHOR]

During the last two decades, cellulose nanofibres (CNF) have emerged as a promising, sustainable reinforcement with outstanding potential in material sciences. Though application of CNF in papermaking is recent, it is expected to find implementation in the near future to give a broader commercial market to this type of cellulose. The present review highlights recent progress in the field of the application of cellulose nanofibres as additives in papermaking. The effect of CNF addition on the wet end process is analysed according to the type of pulp used for papermaking. According to the literature consulted, improvement in paper’s overall properties after CNF addition depended not only on the type and amount of CNF applied, but also in the pulp’s origin and treatment. Bulk and surface application of CNF also presented significant differences regarding paper’s final properties. This review also revises the mechanisms behind CNF reinforcing effect on paper and the effect of chemically modified CNF as additives. [ABSTRACT FROM AUTHOR]

A kind of paper-based composite was prepared with short carbon fibers (CFs) and para-aramid fibrids through the process of papermaking. The dielectric properties of the paper-based composites at microwave frequency were investigated. Based on the Lichtenecker Rule, the dielectric constants of CFs in composites at different CF concentrations were calculated. The absorbing performances of paper-based composites were calculated from the test results of electromagnetic parameters. It was shown that for the composites loaded with 1 mm CFs, the real part of complex permittivity rises at first then tends to be stable with the increase of the CF content, and the imaginary part rises at first then falls slightly, while for composites loaded with 3 or 6 mm CFs, both the real and imaginary part of complex permittivity grows at first and then falls rapidly with the CF content increasing. When the CF content is below 10 wt%, the composites containing longer CFs have larger permittivity at the same concentration. The Lichtenecker Rule is found to be not suitable for the system studied in this paper, especially when the content of CFs is high. The variations of reflectance and absorbance with the content of CFs generally have analogous trends . It is also found that to achieve better absorbing performance, the length and content of CFs together with the thickness of composites should be considered. In this study, the lowest reflection loss at 10 GHz reaches –27.59 dB when the paper-based composite is loaded with 1 mm CFs at the concentration of 10 wt% and the optimum thickness of 1.84 mm. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO)/cellulose paper was prepared by adding aqueous dispersion of GO into cellulose fiber pulp in a traditional papermaking procedure. Cationic polyacrylamide (CPAM) was added as a mordant to induce the self-assembly of GO layers on the fiber surfaces. The surface morphology, mechanical properties and gas permeability of GO/cellulose paper with varying GO contents were investigated by scanning electron microscopy (SEM), tensile test, burst test, tear test and densometer. It was found that CPAM could prevent the self-aggregation of GO in fiber matrix and increase the loading efficiency of GO to up to 16 wt% without sacrificing the mechanical performances of the paper. This finding permitted the large scale preparation of GO/cellulose paper with high doping amount of GO, which exhibited dense and compact geometry and low gas permeability ideal for potential packaging applications. [ABSTRACT FROM AUTHOR]

This article presents a novel method for integrating native corn starch and calcium carbonate (CaCO 3 ) into a hybrid pigment, which can be applied in papermaking to increase the amount of starch in paper and improve sheet bonding without impairing dewatering. Starch was first thermally treated to partially gelatinize and swell the granules. The aim of the treatment was to change the surface properties of starch and thus to improve the interaction with CaCO 3 particles. CaCO 3 shell was precipitated around the swollen granules and the encapsulated starch was then cooked to achieve complete gelatinization. When the granules were cooked, the starch became active for bonding, but its solubility was very limited due to the encapsulation. Particle size measurement and scanning electron microscopy were used to analyze the sample properties during the preparation. The hybrid pigment was added to paper sheets and its effect on the paper properties was examined. Starch was shown to be effectively bound to the pigment structure. The hybrid pigment allowed a large amount of native corn starch to be added to paper without interfering with the papermaking process. Furthermore, it gave excellent mechanical paper properties. [ABSTRACT FROM AUTHOR]

The present work studies the feasibility of wheat soda pulp as a raw material for the fabrication of cellulose nanofibres and their application as an additive in papermaking. Wheat straws were cooked under alkaline conditions and the resulting pulp was used as a raw material for the production of lignocellulosic nanofibres (LCNF). Nanofibres were fabricated by intense mechanical beating followed by high-pressure homogenization. The produced LCNF were characterized and applied to papermaking slurry based also on wheat straw soda pulp. Paper sheets made thereof were analysed for their physical and mechanical properties. The results indicated that paper strength was improved after addition of LCNF, whereas density increased and porosity was reduced. These improvements in properties (except the Tear Index) are significant because they were achieved using LCNF with lower fibrillation degree compared to previous works where chemically pre-treated LCNF were used as reinforcement. [ABSTRACT FROM AUTHOR]

A novel algorithm has been developed and validated to isolate individual papermaking fibres in micro-computed tomographic images of paper handsheets as a first step to characterize the structure of the paper. The three-step fibre segmentation algorithm segments the papermaking fibres by (i) tracking the hollow inside the fibres via a modified connected component methodology, (ii) extracting the fibre walls using a distance transform and (iii) labelling the fibres through collapsed sections by a final refinement step. Furthermore, postprocessing algorithms have been developed to calculate the length and coarseness of the segmented fibres. The fibre segmentation algorithm is the first ever reported method for the automated segmentation of the tortuous three-dimensional morphology of papermaking fibres within microstructural images of paper handsheets. The method is not limited to papermaking fibres, but can be applied to any material consisting of tortuous and hollow fibres. [ABSTRACT FROM AUTHOR]

Water soluble cationic chitosan (C-Ch) and surface-modified microfibrillated cellulose (C-MFC) were prepared and characterized. C-MFC was prepared by reaction of MFC (microfibrillated cellulose) with β-chloroethyldiethylamine followed by quaternization using methyl iodide while C-Ch was prepared by reaction of a commercial chitosan (Ch) with 2,3-epoxypropyltrimethyl ammonium chloride. C-Ch and C-MFC were characterized by elemental analysis (nitrogen content), Fourier transform infrared spectroscopy (FTIR) and surface charge determination. The prepared C-Ch and C-MFC were used with bentonite in order to improve drainage and filler retention in paper handsheets made from softwood and bagasse pulps. Dosage rates were 0.05–0.2% (w/w, weight of additive by weight of fibres) and 0.05–1% (w/w) for C-Ch and C-MFC, respectively. When used alone, these polymers did not induce any noticeable effect on drainage but they improved the retention of ground calcium carbonate (GCC). The effect of C-MFC/bentonite and C-Ch/bentonite systems on filler retention was more pronounced in case of bagasse pulp than for softwood pulp. The use of C-Ch improved filler retention more than C-MFC did. Comparisons with a commercially available cationic polyacrylamide (CPAM) showed that CPAM was the most efficient additive regarding both drainage and GCC retention, followed by Ch, C-Ch, and finally C-MFC. [ABSTRACT FROM AUTHOR]