Southern pine

Chemical charge, Hquor composition, time of heatup, and time at temperature of reaction are all functions of the wood species or species mix being digested and the intended use of the pulp. A typical set of conditions for southern pine chips in the production of bleachable-grade pulp for fine papers is active alkaH, 18% sulfidity, 25% and Hquor-to-wood ratio, 4 1. Time of heatup is 90 min to 170°C time at temperature of reaction, 90 min at 170°C. Hardwoods require less vigorous conditions primarily because of the lower initial lignin content. 

Wood Delignijication. The production of wood pulp (qv) for the paper (qv) industry consists of removing lignin (qv) from wood chips, thus freeing the ceUulose fibers. An aqueous solution containing 30—70 wt % sulfolane efficiently extracts the lignin from aspen. Western hemlock, and Southern pine wood chips. Pulp yields are from 50—75% (43,44). 

CTO prices are closely tied to the cycles of the U.S. economy and the paper industry. They vary between 120 and 220 per metric ton. In 1995 they were close to 200/t (4). With 50% of pine wood being converted to linerboard valued at 400— 600 per ton, pulp manufacturers do not focus on optimum black Hquor soap recovery, which only amounts of 60—70 kg/1 of southern pine pulp. This soap is converted to 30—35 kg of CTO, worth 6— 7 or less than a Htde over 1% of the pulp value (5). This recovery is only 45% of the CTO available in the pine tree. With more care and higher CTO prices, 10—15 kg of additional CTO could be obtained per ton of pulp (6). 

Drying. The living tree holds much water in its cells. A southern pine log, 5 m long and 0.5 m in diameter, for example, may weigh as much as 1000 kg and contain 47% or 0.46 m (16 fE) water. 

W. S. Thompson, Effect of Chemicals, Chemical Atmospheres, and Contact with Metals on Southern Pine A Review, Research Report 6, Eorest Products Utilisation Laboratories, Mississippi State University, State College, Miss., 1969. 

In 1932, the first plywood hot press was installed in the United States. This marked the advent of the large market for phenolic wood adhesives [51]. By 1962, the volume of phenolic wood adhesives had reached about 33 kt (solids) in the U.S. Growth was accelerated in 1962 with the development of Southern pine plywood. By 1979, the consumption of phenolic plywood adhesives exceeded 220 kt or about 25% of phenolic resin production [51]. Phenolic adhesive demand for wood products took another jump in 1964 with the commencement of waferboard production. The first oriented strandboard (OSB) plants were built in 1981 [52]. OSB soon replaced most of the waferboard production and began a period of... 

W Western Wood Products Association S -r Southern Pine Inspection Bureau R - Redwood Inspection Senicc... 

High-alpha pulp from Southern pine 94.5-95.0 7.5... 

Differences in reactivity between wood species have been observed, which can be attributed to a number of factors. Rowell etal. (1986c) acetylated southern pine and aspen flakes under identical reaction conditions, and found that the softwood species exhibited a higher rate of reaction. Beckers and Militz (1994) performed a pilot-scale study of the acetylation of beech, eucalyptus, poplar, pine, Douglas fir and spruce, finding considerable differences in reactivity between the woods studied. 

Gloeophyllum trabeum Southern pine 14.8 68 Ibach and Rowell (2000)... 

Rowell etal. (1987b) produced PF-bonded flakeboard from acetylated southern pine (21.6 % WPG) or aspen (17.6 % WPG) flakes. This was not completely resistant to attack by termites Reticulitermes flavipes) in a 4-week test. It was thought that acetylation was less effective in preventing termite attack than other chemical modifications because cellulose decomposition in the intestines of termites leads to acetic acid formation in any case. 

Chen, G.C., Rowell, R.M. and ElUs, W.D. (1990). Fungal resistance of southern pine impregnated with methyl fluorophenyl carbamates or reacted with fluorophenyl isocyanates. Wood and Fiber Science, 22(2), 165-172. 

Chow, P., Harp, T., Meimban, R., Youngquist, J.A. and Rowell, R.M. (1994). Biodegradation of acetylated southern pine and aspen composition board. International Research Group on Wood Preservation, Doc. No. IRGAVP 94 0020. 

Chow, P., Bao, Z., Youngquist, J.A., Rowell, R.M., Muehl, J.H. and Krzysik, A.M. (1996b). Properties of hardboards made from acetylated aspen and southern pine. Wood and Fiber Science, 28(2), 252-258. 

EUis, W.D. and Rowell, R.M. (1984). Reaction of isocyanates with southern pine to improve dimensional stability and decay resistance. Wood and Fiber Science, 16(3), 349-356. 

Hon, D.N.S. and Bangi, A.P. (1996). Chemical modification of juvenUe wood. Part 1. JuvenUity and response of southern pine OSB flakes to acetylation. Forest Products Journal, 46(7/8), 73-78. 

Rowell, R.M. (1977b). Effects of drying method and penetration of chemicals on chemically modified southern pine. Wood Science, 9(3), 144-148. 

Rowell, R.M. (1978). Distribution of reacted chemicals in southern pine treated with aUcylene... 

Rowell, R.M. and Ellis, W.D. (1979). Chemical modification of wood reaction of methyl isocyanate with southern pine. Wood Science, 12(1), 52-58. 

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