Thermomechanical Pulping of Loblolly Pine Juvenile Wood
Keywords:Loblolly pine, <i>Pinus taeda</i>, mature wood, juvenile wood, mechanical pulping, thermomechanical pulping, pulp properties, paper properties
AbstractIntensive forest management, with a heavy emphasis on ecosystem management and restoring or maintaining forest health, will result in the removal of smaller diameter materials from the forest. This increases the probability of higher juvenile wood content in the harvested materials. The purpose of this study was to compare the performance of loblolly pine juvenile and mature wood unbleached thermomechanical pulp (TMP). The TMPs were prepared without screening (unscreened TMP) and after screening (screened TMP). Pulp and paper properties were tested. Paper made from screened juvenile and mature wood TMP had better properties than those of paper made from unscreened juvenile and mature wood TMP. The results also show that screened juvenile wood TMP consumed a large amount of electrical energy to produce a long-fibered pulp with low fines content and low coarseness. It might be possible to substitute the screened juvenile wood TMP for some of the reinforcing kraft pulp needed to manufacture newsprint and printing and writing papers. This could lower production costs of these paper grades.
Carpenter, C. H. 1984. The mechanical pulping of southern pine containing relatively large amounts of spring and juvenile fiber. Symposium on utilization of changing wood resource in southern United States, June 12-13, 1984, North Carolina State University. Raleigh, NC.nCorson, S. R. 1999a. Tree and fibre selection for optimal TMP quality. Appita J.52(5):351-357.nCorson, S. R. 1999b. Process impacts on mechanical pulp fibre and sheet dimensions. TAPPI International mechanical pulping conference, May 24-26, 1999, Houston, TX.nHattton, J. V., and S. S. Johal. 1994. Mechanical and chemithermomechanical pulps from second-growth softwoods. Pulp Paper Canada95(12):67-73.nKirk, D. G., L. G. Breeman, and B. J. Zobel. 1972. A pulping evaluation of juvenile loblolly pine. Tappi J.55(11):1600-1604.nMiles, K. B. 1991. A simplified method for calculating the residence time and refining intensity in a chip refiner. Paperi ja Puu73(9):852-857.nMurton, K. D. 1998. Refining intensity impact on slab-wood and thinnings TMP. Appita J.51(6):433-440.nSemke, L. K. 1984. Effects of juvenile pine fibers on kraft paper properties. Symposium on utilization of changing wood resource in southern United States, June 12-13, 1984, North Carolina State University, Raleigh, NC.nThomas, R. J. 1984. The characteristics of juvenile wood. Symposium on utilization of changing wood resource in southern United States, June 12-13, 1984, North Carolina State University, Raleigh, NC.nZobel, B. J, and J. P. van Buijtenen. 1989. Wood variation: Its causes and control. Springer-Verlag, New York, NY.n
The copyright of an article published in Wood and Fiber Science is transferred to the Society of Wood Science and Technology (for U. S. Government employees: to the extent transferable), effective if and when the article is accepted for publication. This transfer grants the Society of Wood Science and Technology permission to republish all or any part of the article in any form, e.g., reprints for sale, microfiche, proceedings, etc. However, the authors reserve the following as set forth in the Copyright Law:
1. All proprietary rights other than copyright, such as patent rights.
2. The right to grant or refuse permission to third parties to republish all or part of the article or translations thereof. In the case of whole articles, such third parties must obtain Society of Wood Science and Technology written permission as well. However, the Society may grant rights with respect to Journal issues as a whole.
3. The right to use all or part of this article in future works of their own, such as lectures, press releases, reviews, text books, or reprint books.