Kraft Pulping of Young Trembling Aspen from Manitoba

Abstract

The unscreened kraft pulp yields at permanganate No. 14 for 7-, 13-, and 22-year-old trembling aspen (Populustremuloides Michx.) trees from Manitoba for effective alkali applications of 14% were 56.2, 55.7, and 54.8% (o.d. wood), respectively. Specific gravity data for green and ovendry wood are presented, but no relationship with tree height could be established. Pulp strength values from the 7-, 13-, and 22-year-old aspen were, respectively, 60, 67, and 65 for tear factor; 67, 71, and 72 for burst factor; and 10.1, 10.4, and 10.7 (km) for breaking length, respectively. These data indicate that trees of any of the three ages will make a kraft pulp comparable in yield and strength to commercial hardwood–softwood pulp.