PAPERmaking! FROM THE PUBLISHERS OF PAPER TECHNOLOGY Volume 5, Number 2, 2019
with surface coating. Ultraviolet (UV) light in sunlight causes changes in the structure of the paper and coating chemicals and accordingly causes yellowing. Para-amino benzoic acid (PABA), due to its chemical structure, is a UV-blocking agent used in sunscreen creams. CO2 capture and preparation of spindle-like CaCO3 crystals for papermaking using calcium carbide residue waste via an atomizing approach, Liang Ma et al, Korean Journal of Chemical Engineering , 36 (9), pp.1432 – 1440 . Spindle-like CaCO 3 crystals with controllable sizes for papermaking were successfully prepared using CO 2 (8% CO 2 /N 2 mixture gas) and calcium carbide residue (CCR) waste, a by-product of acetylene gas and polyvinyl chloride production, as the raw materials by an atomization method at room temperature. The influences of solution concentration, reaction temperature, and gas/liquid flow rate ratios on the properties of the CaCO 3 crystal were systematically investigated, and a possible atomization mechanism was proposed. The size of the as-prepared CaCO 3 crystal with pure calcite phase was turned from 4.71×4.02 μm to 1.82×1.12 μm by adjusting the reaction conditions. The application of the as-prepared CaCO 3 crystals from CCR waste as a filler for papermaking was explored. The R475 blue light whiteness of paper was increased from 77.3 to 80.6 with 11.4% CaCO 3 crystals. Nanocellulose in the Paper Making, Elaine Cristina Lengowski et al, Sustainable Polymer Composites and Nanocomposites , Springer, pp.1027-1066. In recent times, nanotechnology, which has been one of the main novelties to be developed in the 21st century, has been applied to many sectors, particularly to various industrial sectors including forest-based industry. An output of this is the development of nanomaterials of which nanocelluloses have been studied as high technology biopolymers for application in various materials through the development of films and as reinforcement in papers. With this background, the main objective of this Chapter is to present the use of nanocellulose in the paper making. Accordingly, the Chapter presents characteristics of the most used wood in the world for pulp and paper production, main methods of obtaining cellulose in nature, process of bleaching of pulp, paper making, processes to obtain different types of nanocellulose (microfibrillar nanofiber and cellulose nanocrystals), applications of nanocellulose in the paper making through coating and films as well as by nanocellulose- reinforced pulp and the resulting effects of the use of nanocellulose in paper production. These include increased tensile and burst strengths, weight loss, improved barrier properties for oils, oxygen and moisture, better printing surface, etc. In the end, marketing aspects, possible future opportunities and finally concluding remarks are given. These briefly mention the use of nanocelluloses in papermaking presenting interesting possibilities, which offer improvements in cost-benefit, energy efficiency and biocompatibility, in addition to generating new products with uses are not available today. PULP / PULPING A structural fibrillation parameter from small angle X-ray scattering to quantify pulp refining, Jia Mao et al, Cellulose , 26 (7), pp.4265 – 4277. Pulp fibrillation results from refining and is of prime importance for papermaking. Yet a structural parameter reflecting the extent of fibrillation remains elusive. In this work, we demonstrate that in refined pulps, the interfibrillar distance at water saturated state (L s ), as derived from the interference factor from small angle X-ray scattering, structurally reflects fibrillation degree. Interestingly, the minimal L obtained at low water content is close to the crystal thickness derived from wide angle X-ray scattering. For a series of refined pulp samples, significant regressions are established between L s and equilibrium moisture content, transmittance (T%), surface energy components (γ LW , γ AB ), and the normalized crystallinity index (CrI n ).
Technical Abstracts
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