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Abstract
Color, odor, and natural durability of heartwood are characteristics imparted by a class of chemicals in wood known collectively extractives. Wood is converted by the tree from sapwood to heartwood by the deposition of extractives, typically many years after the growth ring undergoing this change was formed by the tree. Extractives are thus not a part of the wood substance, nor do they play a major role in the mechanical strength of wood, but rather are additional materials added as a part of the natural aging process of the tree. Most commercial species that are valued for their appearance owe their merchantability, at least in part, to characteristics imparted by their extractives.
Keywords
Wood quality,
wood chemistry,
heartwood,
deterioration,
sapwood,
wood moisture,
moisture,
solubility,
finishes,
finishing,
wood finishing,
wood extractives,
knots,
decay,
durability,
decomposition,
bleed,
discoloration,
moisture content,
pitch,
failure
Citation
Burke, Edward; Slavik, Norm; Bonura, Tony; Connelly, Dennis; Faris, Tom; Nebelsick, Arnie; Stuart, Brent; Williams, Sam; Wiedenhoeft, Alex C. 2010. Understanding extractive bleed : wood extractives: distribution, properties, and classes. CoatingsTech. Vol. 7, no. 3 (Mar. 2010): p. 48-53.
