PAPERmaking! FROM THE PUBLISHERS OF PAPER TECHNOLOGY Volume 7, Number 2, 2021
“ Assessment of the papermaking potential of processed Miscanthus × giganteus stalks using alkaline pre-treatment and hydrodynamic cavitation for delignification ”, Dimitrios Tsalagkas, Zoltán Börcsök, Zoltán Pásztory, Parag Gogatec & Levente Csóka, Ultrasonics Sonochemistry , Vol.72, April 2021. One way of satisfying increased market demand and simultaneously achieving a reduced environmental load in the industrial paper production is the use of fibrous agricultural residues. The aims of this study were i) to investigate the effect of alkaline – hydrodynamic cavitation (HC) pre- treatments on the delignification of Miscanthus × giganteus stalks (MGS) and ii) establishing the suitability of MGS as feedstock and their exploitation in pulp and paper manufacturing. It was demonstrated that the proposed treatment is an efficient delignification method for the non-wood fiber sources, such as miscanthus. A significant outcome of this work was the observation that HC treatment preserved the fibres lengths and surface quality of raw MGS, but at the same time increased the amount of kinked and curled fibers present in cavitated miscanthus fibers. The average miscanthus fiber length was found to be relatively short at 0.45 (±0.28) mm, while the slenderness ratio, the flexibility coefficient and Runkel ratio values were calculated to be 28.13, 38.16 and 1.62, respectively. The estimated physical properties of MGS pulp hand-sheets were 24.88 (±3.09) N m g−1 as the tensile index, 0.92 (±0.06) kPa m2 g−1 as the burst index and 4.0 (±0.37) mN m2 g−1 as the tear index. Overall the current work demonstrated effective use of hydrodynamic cavitation for improving the processing in pulp and paper manufacturing. COATING “ The fluorine-free coating has excellent hydrophobic and oleophobic properties for porous cellulose-based materials ” , Peng Du, Qijun Ding, Chuanshan Zhao, Yifei Jiang, Wenjia Han & Xia Li Cellulose , Vol.28, pp.6133 – 6146 (2021). Nanofibrillated cellulose is obtained from cellulose resources (e.g., Natural cellulose, bacterial cellulose) and is deemed to be environmentally friendly, green, and inexhaustible. Accordingly, we reported an innovative method for fluorine-free water- and oil/grease-repellent surface based on porous cellulose-based materials. In order to improve oil/grease resistance, sulfonated nanofibrillated cellulose (SNFC) was coated on the surface to fill the pores, the obtained paper was soaked in chitosan aqueous solution as the second layer. The-SNFC- chitosan-coated paper was applied with modified polyvinyl alcohol (MPVA) as the third layer to increase water resistance and water vapour transmittance. The experimental results showed 5.2 g/m2 SNFC, 2.5 g/m2 chitosan and 7% MPVA demonstrated excellent kit rating value of 12/12 (maximum grease resistance) (oil resistance contact angle is 103.93°), good water resistance (water contact angle is 108.6°) and high water vapour transmission rate (4.8 × 10–14 g cm/cm2 s Pa) under the condition of 90% relative humidity. This non-fluorinated and practical method is an excellent alternative to existing fluorinated materials, which will further promote the development of cellulose-based packaging. “ Investigation of Industrial Paper Coating with Recycled Kaolin ”, Journal of Color Science and Technology, F. Mortazavi, H. Resalati, S. Rasouli & Gh. Asadpour, Journal of Color Science and Technology , Vol.15 (2), Summer 2021, pp.117-129. The paper coating process has a special place in the paper industry in order to reduce production costs and improving quality. In this study, kaolin was first extracted from waste paper and XRD, FTIR, SEM/EDX analysis are used to investigate the microstructural properties of kaolin recycled from waste paper. Then, the coating solution of Recycled kaolin was coated on paper at four levels of thickness 30, 60, 90, and 120 micrometers. Based on the study of permeability properties and mechanical properties, the superior treatment was related to coated paper with 120 micrometers thickness.
Technical Abstracts
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