PAPER making! g! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL ® Volume 10, Number 1, 2024
well as hydrophobicity, using a simple, efficient, and environmentally friendly method, making it a promising substitute for petroleum-based plastics. PACKAGING TECHNOLOGY “A novel paper -based composite film with enhanced oxygen and water vapor barrier properties”, Xiangjie Chen, Bin Xiao, Yutian Yang, Yu Jiang, Xiaoming Song, Fushan Chen, Wentao Wang, Jianqing Wu & Yao Meng, Progress in Organic Coatings , Vol.186, Jan. 2024, 108042 . Paper-based composite films have demonstrated significant potential in the field of packaging materials. However, the gas barrier properties of these films have been found to be less than satisfactory, primarily due to the inherent porosity and hydrophilic nature of cellulose-based paper. Consequently, the challenge of enhancing the gas barrier performance, particularly in relation to oxygen and water vapor, remains a formidable obstacle. In this study, drawing inspiration from the well-established multilayer composite model, which incorporates both organic and inorganic layers, an efficient strategy has been devised to enhance the gas barrier performance of paper- based packaging materials. The organic barrier layers in this approach utilize polyvinyl alcohol and polyacrylate. Meanwhile, the critical inorganic barrier layer is composed of functionalized SiO2@polydopamine nanoparticles (SiO2@PDA NPs). Importantly, due to the isotropic nature of the SiO2@PDA NPs, concerns related to the orientation control and exfoliation of 2D layered materials are alleviated within this system. The introduction of a crosslinker, 3-aminopropyl triethoxysilane, serves to bridge the gap between SiO2@PDA NPs, facilitating the tight concatenation of NPs through Schiff base or Michael addition reactions. Utilizing coating technology, a paper-based multilayer film was fabricated. As a result, the oxygen transmission rate of the composite film was substantially reduced to 0.3077 cm 3 /cm 2 ·24 h·0.1 MPa, and the water vapor transmission rate was lowered to 4.1109 g/m 2 ·24 h. Significantly, these composite films exhibit exceptional water resistance and mechanical properties, rendering them highly suitable for the packaging of a wide range of sensitive products, including food items, pharmaceuticals, electronic devices, and other gas-sensitive products. PAPERMAKING “Enzyme -assisted dewatering and strength enhancement of cellulosic fibers for sustainable papermaking: A bench and pilot study”, Nelson Barrios, Madilynn M. Smith, Richard A. Venditti & Lokendra Pal, Journal of Cleaner Production , Vol.434, 1 Jan. 2024, 140094. Water removal during paper manufacturing is of primary importance to production rate and cost efficiency for the pulp and paper industry. It is crucial to develop methods to reduce energy consumption by increasing the percent solids in the paper web entering the dryers from the presses. This research aimed to develop a fundamental understanding of the effect of bio-chemo-mechanical pretreatments on a bleached softwood fiber matrix and evaluate the impact on the percent solids of the paper web after pressing. Experiments included enzymatic, refining, and cationic polymer pretreatments on the bleached softwood pulps, followed by laboratory papermaking and determining the equilibrium moisture content (EMC) after pressing and the pulp and paper properties. The combined effect of mild refining, controlled enzymatic pretreatments, and cationic strength aids proved to enhance the water removal during wet pressing (up to 35 % reduction) and increase paper strength (up to 60 % increase). The results of increased solids after pressing were used to calculate the potential reduction in drying energy during paper manufacturing. Energy savings of around 10 % for paper drying could be achieved through fiber matrix modification by bio-chemo-mechanical pretreatment. Enzymatic pretreatments have previously been conventionally applied before refining as an energy-saving method. However, this research shows that synergistic actions of enzymes added after refining
Technical Abstracts
Page 5 of 11
Made with FlippingBook Annual report maker