Chemical Composition, Fiber Morphology, and Kraft Pulping of Bracken Stalks (Pteridium aquilinum (L.) Kuhn)

In this study, kraft, kraft-NaBH4, and kraft-KBH4 pulp and paper properties of the bracken stalks (Pteridium aquilinum (L.) Kuhn) were determined. Also, the chemical composition and fiber properties of bracken stalks were evaluated. NaBH4 and KBH4 were separately added to cooking liquor by 0.5 %, 1 %, 1.5 %, and 2 % (oven dried wood). The boron compound-free kraft pulp were also made as control pulp. Fiber length and fiber width of bracken stalks were determined as 1.25 mm and 24 μm, respectively. Bracken stalks are composed of 73.34 % holocellulose, 32.55 % α-cellulose, and 30.79 % lignin. In addition, the pulp yield was increased with additions of both boron compounds, while kappa number was decreased. Also, highest strength increases determined in 0.5 % NaBH4 added pulp. These results showed that bracken stalks can be used as a raw material for kraft pulp production.