The effects of heartwood and sapwood on kraft pulp properties of Pinus nigra J.F.Arnold and Abies bornmuelleriana Mattf

Abstract

The effects of heartwood and sapwood on kraft pulp properties of Pinus nigra J.F.Arnold. and Abies bornmuelleriana Mattf. were investigated. The differences in terms of chemical composition and fiber properties between the heartwood and sapwood of these species were also examined. Heartwood had more holocellulose and extractive compared to sapwood. Moreover, heartwood fiber length was shorter than that of sapwood. Kraft cookings of heartwood and sapwood each species were separately done under fixed cooking conditions. The results indicated that heartwood pulp had lower pulp viscosity and total pulp yield than sapwood did. The tear index of sapwood unbeaten and beaten kraft pulp was higher than that of heartwood. However, the burst and tensile indices of heartwood unbeaten and beaten kraft pulp were higher than those of sapwood. © TÜBİTAK.