PAPER making! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL ® Volume 8, Number 1, 2022
thoroughly studied, as well as the optical, morphological and mechanical properties. All examined species ( Ailanthus altissima , Fallopia bohemica , Fallopia japonica , Rhus typhina , Robinia pseudoacacia , Rudbeckia laciniata and Solidago canadensis ) contain relatively high amount of C6 polysaccharides (> 35%), have notable hemicellulose content (30 –40%), low ash content (< 2%) and can be easily delignified, while manufactured natural fibers exhibit convenient morphology (fiber length 0.47 – 0.88 mm; width 14.4 – 20.9 μm), optical (ISO whiteness 19.0– 36.0%) and mechanical characteristics (tensile index 18.0 – 58.0 Nm/g; tear index 0.8 – 4.1 mN m 2 /g; and burst index 0.5 – 2.4 kPa m 2 /g indices), which makes them applicable to sustainable paper production. The pulp yields varied between 34 – 44%, where both darker herbaceous and brighter woody fibers were morphologically comparable to typical hardwoods. According to the observed properties Robinia pseudoacacia and Rudbeckia laciniata seem to be superior raw material for commercial papermaking products. The ubiquitous invasive plants pose a huge potential for the circular economy, especially in terms of their cascade valorisation of biorefinery by the isolation and valorization of hemicellulose, sugars, and lignins into added-value aromatic and aliphatic building blocks. However, promising yield of cellulose fibers of decent morphology and mechanical properties are reported in this study. “ Influences of Fiber and Pulp Properties on Papermaking Ability of Cellulosic Pulps Produced from Alternative Fibrous Raw Materials ”, Edyta Małachowska , Aneta Lipkiewicz, Marzena Niemczyk, Marcin Dubowik, Piotr Boruszewski & Piotr Przybysz, Journal of Natural Fibers , Vol.18(11), pp.1751-1761, (2021). The analyzes of cellulosic fibers and properties of cellulosic pulps are extremely important in the process of paper production. If the set point is known, we can predict fairly accurately the effects of fiber dimensions and pulp properties on the final product, which would consequently help in the precise selection of fibrous raw material types suitable for specific recipes and paper applications. In this study, the correlations between the dimensions of cellulosic fibers of alternative fibrous raw materials, pulp properties, and paper were investigated to predict paper strength based on the parameters characterizing the pulp. “Novel bulking technologies for cellulose fibres”, Tom Lindström & Gunborg Glad - Nordmark, Nordic Pulp & Paper Research Journal , (2022) online. This paper deals with the details of preparation of three principal routes for bulking of cellulose fibres. One route is dry cross-linking/hornification using aluminium ions and other salts followed by drying/curing. The mechanisms of these reactions still remain unknown. A second route is physical grafting of fibres using carboxymethylcellulose and bringing the acidic groups into their aluminium form before forming a sheet of paper/board. Hence, curing is not necessary, and this constitutes a unique wet bulking methodology. The mechanism behind this method is believed to be an increase in the surface friction of fibres, when the electrostatic double layer is shielded together with electrostatic cross-linking with aluminium ions. The higher friction between fibres partly prevents the sheet consolidation during drying. A third route is physical grafting of fibres using carboxymethyl cellulose and ion-exchanging the acidic groups with aluminium salts before drying and curing of the fibres. A most interesting factor is that all the thermal treatment methods do not form fibre nodules due to interfibre crosslinking during the heat treatment, a commonly observed phenomena when dealing with chemical crosslinking of fibres. All routes investigated are water-based and should be fairly simple to implement in commercial operations. An inherent advantage is that the bulking is associated with lower water retention values, which should be advantageous for a higher solids content after pressing and, hence, beneficial for paper machine productivity. Bulking is, however, also associated with a loss in bond strength, which in most cases must be alleviated using various additives such as
Technical Abstracts
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