PULPING AND BLEACHING OF PARTIALLY CAD-DEFICIENT WOOD

ABSTRACT Mutant loblolly pine trees that are partially deficient in cinnamyl alcohol dehydrogenase (CAD) have been studied as a possible new source of pulpwood. Young (4- and 6-year-old) partially CAD-deficient pine trees are ˜20% more easily delignified (pulping and bleaching) and provide similar pulp yields to that of similarly aged normal pines grown on the same plots. Bleached pulp from a 6-year-old partially CAD-deficient pine tree displayed better strength properties than the same age normal pine tree; this probably reflects the milder pulping conditions needed in the case of the partially CAD-deficient tree. Studies also were conducted on a limited number of 14-year-old trees from a different genetic background. In contrast to the results with young trees, no real differences in ease of delignification, pulp yields, bleached pulp strength properties, and wood specific gravities were observed with the 14-year-old trees. There would likely be no penalty if partially CAD-deficient trees were used for ...