PAPERmaking! FROM THE PUBLISHERS OF PAPER TECHNOLOGY Volume 5, Number 1, 2019
Fabrication of food-safe superhydrophobic cellulose paper with improved moisture and air barrier properties, Hui Li et al, Carbohydrate Polymers , Vol.211. We presented a facile method for preparing a food-safe superhydrophobic packaging paper with improved moisture and air barrier properties in this study, which is combining construction of polymer-nanoclay hybrid multilayers with subsequent carnauba wax treatment. The obtained paper was used for strawberry packaging at ambient temperature, and it was very effective at reducing the weight loss and maintaining titratable acidity compared with the unpackaged strawberries, which might has a great potential as food packaging materials. Highly transparent and thermally stable cellulose nanofibril films functionalized with colored metal ions for ultraviolet blocking activities, Weisheng Yang et al, Carbohydrate Polymers , Vol.213. Although many preparation methods have been reported so far, it is still a great challenge for Ultraviolet (UV) protection films that simultaneously have extremely high transparency and excellent UV shielding properties. Herein, we reported a simple, eco-friendly process for preparing high transparency TOCN- COOM (M: metal ions) films with diverse UV-shielding performances via adsorption of coloured metal ions (Fe3+, Co2+, Ni2+, Cu2+). The introduction of Fe3+ led to an excellent UV blocking, especially almost 89% absorption of Ultraviolet A (UVA) and full absorption of Ultraviolet B (UVB). The formation of metal-carboxylate complexes is also advantageous for improving thermal stability. Hence, the obtained TOCN-COOM films have wide application prospect in the field of UV shielding. Role of the Relaxation State of Polymer Components in Wood When Making Composite Packaging Materials (Corrugated Cardboard), E. L. Akim et al, Fibre Chemistry , Vol.50 (4). We consider targeted variation of the relaxation state for polymer components of wood in stages of the life cycle of corrugated cardboard. From the standpoint of the structural physicochemistry of wood, we present a mechanism for the processes occurring in traditional corrugated cardboard production technology. Our thesis is that cellulose and hemicellulose can go from the glassy state to the rubbery (highly elastic) state at 220°C, but under real conditions this transition occurs at room temperature and even at negative temperatures in the case of plasticization by a sufficient amount of water. Transition of lignin from the glassy state to the rubbery state occurs at a temperature above 130°C, and at 70°C-120°C under conditions of sufficient hydration. Formation of strong interfibre bonds is possible only when the polymers forming the contact are in the rubbery or viscous-flow state. PAPERMAKING Study on the wet-web strength and pressability of paper sheet during the press process with the addition of nano-fibrillated cellulose (NFC), Zonghong Lu et al, Carbohydrate Polymers , Vol.210. The properties of wet-web strength and pressability of base paper affect the frequency of sheet breaks and machine runnability during the paper- making process. In this paper, the effect of nano-fibrillated cellulose (NFC) on the wet-web strength and pressability of paper sheet during the press process of paper-making was explored. It was found that the tensile energy absorption (TEA) of the sample was increased from 6.32 to 10.93 J/m 2 at 50% wet web solid content when 5% NFC was added. The web solid content was decreased from 50.51% to 42.85% when 0%-5% NFC was added under the same drainage and press conditions, indicating that the addition of NFC during the paper-making process can retard the pressability of paper sheet. The study put forwards a new view to discuss/study the effect of added NFC on the wet-web strength and pressability of paper sheet.
Technical Abstracts
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