Influence of Sodium Borohydride on Kraft Pulping of Eur pean Black Pine as a Digester Additive

In this study, the effects of sodium borohydride (NaBH(4)) on properties of haft pulp and paper obtained from European black pine (Pinus nigra Am.) were investigated. Kraft-NaBH(4) cookings were done under fixed cooking conditions by adding NaBH(4) in the amounts of 0.5%, 1%, 1.5%, and 2% (oven-dried wood)to the cooking liquor. NaBH(4)-free haft cooking was carried out as control. The results indicated that addition of NaBH(4) to cooking liquor increased the pulp yield. However, the kappa number of pulp and beating time decreased. The brightness of kraft-NaBH(4) papers was found to be higher than that of control papers. Addition of NaBH(4) significantly decreased pulp viscosity and slightly decreased strength properties of papers.