Effects of Intensive Silvicultural Treatments on Kraft Pulp Quality of Loblolly and Slash Pine, 2000 Pulping / Process & Product Quality Conference Proceedings

C. E. Courchene, A. Clark III, M. L. Belli, W. J. Cooper, B. D. Shiver--Intensive forest-management practices have been shown to greatly increase the growth rates of southern pines. A joint study was undertaken to evaluate the wood and pulp quality from fast-grown 14-year-old loblolly pine from the Piedmont and 17-year-old slash pine from the Coastal Plain. The properties were compared to 24-year-old plantation-grown controls. Three sets of chip samples, sawmill residual, top log, and whole stem, were prepared from each wood source. Two unbleached pulp grades, linerboard at kappa no. 90 and sack kraft at kappa no. 60, were prepared from each chip sample, and the pulp yields, fiber lengths, and handsheet properties were compared. A bleachable grade pulp, kappa no. 30, was also made and the pulp yields and fiber lengths measured.

Within each chip type, there was not a significant adverse effect on pulp yield from the intensive management practices for the unbleached grades. Chips from the top log samples with a high proportion of juvenile wood had significantly lower packed bulk density and lower pulp yields than pulps from the sawmill residual chips. For the unbleached grades, there was no overall significant negative impact on handsheet strength from the intensive management practices. Pulps from the top wood chips had higher burst, tensile, and compression strength but lower tear.

For the bleachable grade pulps, there was some loss in pulp yield for the for the accelerated-growth loblolly pine pulps while the accelerated-growth slash pine exhibited no loss in pulp yield compared to the control.