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Fiber Evolution During Alkaline Treatment And Its Impact On Handsheet Properties, Yun Ji, Yangyang Peng, Anders Strand, Shiyu Fu, Anna Sundberg, Elias Antero Retulainen

Chemical Engineering Faculty Publications

To understand the swelling effects of alkaline treatment on the morphological properties of fibers and physical properties of handsheets, bleached softwood kraft pulp was treated with NaOH at different concentrations. The results showed that the fiber swelling increased, but the shrinkage and elongation of the paper at a NaOH concentration of 6% or higher did not improve. Dissolution of amorphous material occurred during the treatment together with peeling reactions. The fiber length and shape factor decreased and the fines content increased with an increasing alkali concentration. The cellulose crystallinity decreased with an increasing NaOH concentration. This was confirmed by X-ray …