Evaluation of the papermaking potential of Ailanthus altissima

In this work, Ailanthus altissima (tree-of-heaven) wood was analyzed for its chemical, morphological and papermaking properties. The A. altissima wood was cooked under kraft conditions using different active alkali charges and then handsheets were produced with the pulps having a kappa number of 16. Based on structural, strength and optical data it was found that the kraft pulp of A. altissima is not suitable to be used alone for the production of printing and writing papers. Notwithstanding, the handsheets exhibit a favorable value of brightness in comparison to those produced from Eucalyptus globulus pulp (with similar kappa number). Therefore, the wood of A. altissima seems to have a good potential to be used as a partial substitute of the main raw material of the Portuguese pulp industry. In fact, the results showed that when beaten E. globulus and A. altissima pulps were mixed (50:50, w/w), the papermaking properties were comparable to those of beaten eucalypt kraft pulps. Therefore, the use of A. altissima wood seems promising for the production of uncoated wood-free papers, which has advantages both from an economical and environmental perspective.

► A. altissima wood exhibits a lower amount of lignin and xylan than E. globulus wood.
► A. altissima kappa-16 kraft pulp shows a lower amount of xylan than a equivalent E. globulus pulp.
► The brightness of A. altissima pulp is significantly higher than that of E. globulus pulp.
► Handsheets with A. altissima unbeaten kraft pulp exhibit weak mechanical properties.
► Mixtures (50/50, w/w) of beaten E. globulus and A. altissima pulps exhibit a good papermaking potential.