Wood and Pulp Properties of Aspen and its Hybrids, 1996 Pulping Conference Proceedings

Salman Aziz

Integrated Paper Services, Inc.

Gary W. Wyckoff

University of Minnesota

Judith L. Wyckoff

Three A kraft pulping study compared young (19-year-old) hybrid aspen to a samples high-quality, 27-year-old source of quaking aspen. All trees were pulpwood size, averaging 8.3 inches in diameter and 59 feet in height for the hybrid sources and 8.2 inches in diameter and 64 feet in height for the quaking aspen source. Wood density for one hybrid source and the quaking aspen source was 0.37 and 0.40 for a second hybrid source. Fiber length, carbohydrate levels and lignin content were similar for all sources, extractives level were modestly higher in the hybrid sources. The bolts were debarked, chipped and screened. The chips were cooked by the Kraft pulping process. To study the bleaching and strength properties, a large sample of each type was pulped to a kappa number of approximately 15. These pulps were bleached using CD E D and O Dc Eo D sequences. The data show that hybrid aspen can be used to replace or supplement native aspen. The advantage of hybrid aspen is that their growth rate is twice that of native aspen. INTRODUCTION The establishment of hybrid aspen plantations is being proposed as a means to help address a predicted aspen fiber shortage. Aspen grows in even-aged stands and must be clearcut at ages 30 - 60 to regenerate. It is the imbalance in age classes available for harvest that hybrid aspen plantations are intended to help fill. Before committing large acreages to hybrid aspen, it is necessary to demonstrate its suitability as a pulpwood sources.