Wood and Wood Products
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INTRODUCTION
Wood has been utilized by humans since antiquity. Trees provided a source of many products required by early humans such as food, medicine, fuel, and tools. For example, the bark of the willow tree, when chewed, was used as a painkiller in early Greece and was the precursor of the present-day aspirin. Wood served as the primary fuel in the United States until about the turn of the century, and even today over one-half of the wood now harvested in the world is used for heating fuel. Throughout history different types of wood have served many purposes. The tough, strong, and durable white oak, for example, w~s a well-proven raw material for ships, bndges, cooperage, bam timbers, farm implements, railroad ties, fence posts, flooring, paneling, and other products. In contrast, *D~part_ment of Forest Ecology and Management, Un1vers1ty of Wisconsin, Madison, Wisconsin. The author wishes to acknowledge the use of material from an earlier edition prepared by Dr E. C. Jahn and Dr R. W. Strauss.
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Riegel Handbook of Industrial Chemistry, 1Oth Edition
Edited by Kent. Kluwer Academic/Plenum Publishers, New York 2003
woods such as black walnut and cherry became primarily cabinet woods. Hickory was manufactured into tough, hard, resilient tool handles. Black locust was used for bam timbers and treenails. What the early artisan learned by trial and error became the basis for intelligent decisions concerning which species was best suited to a given purpose, as well as what characteristics should be looked for in selecting trees for different applications. It was known that wood from trees grown in certain locations was stronger, more durable, and more easily worked with tools than wood from the same species grown in other locations. Modem wood quality research has substantiated that location and growth conditions significantly affect wood properties. 1 In the United States more than 100 kinds of wood are available to the prospective user but ' . . It IS very unlikely that all are available in any one locality. About 60 native woods are of major commercial importance. Another 30 wood types are commonly imported in the form of logs, cants, lumber, and veneer for 177
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RIEGEL'S HANDBOOK OF INDUSTRIAL CHEMISTRY
Reyon
veneer Cellulose derivotill8s
Platies, coatings,, odditi111s
Con111rsion to fuels end feedstock Alcohols, chercoal, phenols, furfural
By-product
Ethenol, vanillin, turpentine, fatty ecids
llood extrection end tree exudates
Tannins, rosin, turpentine
Fig. 7.1. Summary of uses for wood. (From Introduction to Forest Ecosystem Science and Management, 3rd ed., R. A. Young and R. L. Giese (Eds.), Copyright © 2004, John Wiley & Sons, New York; with permission of John Wiley & Sons Publisher.)
industrial uses, the building trades, and crafts. 2•3 The importance of wood as a raw material supplying fiber, energy, and chemicals is similar in magnitude to its use as a solid material. Lumber, plywood, and reconstituted boards consume about one-half of the timber harvest; usage for fiber, chemicals, and
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