- Department of Forest Products, Swedish University of Agricultural Sciences
Heijnesson-Hultén, Anette; Basta, Jiri; Samuelsson, Marie; Greschik, Thomas; Ander, Paul; Daniel, Geoffrey
This study outlines research concerning wheat straw fines, including their impact on pulp bleachability, their modification by chemical means, and their use as a dry strength enhancer in a paper application. Results show that primary fines constituting about 23% of the whole wheat straw pulp had a large negative impact on pulp bleachability. The differences in response to bleaching were due to the different properties of the fines, i.e. higher kappa number, higher metal ion content, lower brightness, and lower viscosity compared to that of fibers. It was also shown that the fines fraction is more difficult to oxidize and does not reach as high fiber charge levels as that of the other fractions. However, at a dosage of >= 3 mmol hypochlorite/g it was possible to prepare nanofibers from wheat straw fines that showed a good strength-enhancing effect in a paper product. The fact that removal of fines from wheat straw pulps by fractionation improves bleachability and also drainage properties at the same time, while simultaneously the fines can be modified and used as a strength enhancer, is very interesting when evaluating the potential of this type of annual plant as a source for production of different paper products.
Wheat straw; Fines; Non-wood fiber; Bleaching; TEMPO; Oxidation; Fiber properties; Strength properties; HCl method; Electron microscopy; SEM; TEM
2012, Volume: 7, number: 3, pages: 3051-3063
Publisher: NORTH CAROLINA STATE UNIV DEPT WOOD & PAPER SCI