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Abstract
Flame retardants for wood alter the combustion properties of wood to reduce surface flame spread. Flame retardant chemicals cause acid catalyzed dehydration reactions in wood to facilitate the formation of char and reduce the effective heat of combustion, resulting in lower heat release and flame spread. Boron compounds can also form glassy fiis that may inhibit mass transfer of combustible vapors. This paper discusses the role of boron in providing flame retardancy to wood. Different loading levels of borax-boric acid, ranging from O to 20 percent add-on by weight, were applied to Southern Pine. Two types of fire tests were used to evaluate flame retardancy. Clearwood and plywood specimens were tested in the fire tube test and in a heat release rate calorimeter, respectively. It was estimated from fire tests results that loading levels of more than 7.5 percent add-on (3 lb/ft/3/] (48 kg/m/3/] of boraxboric acid are required to meet the ASTM E 84 class I for flame retardant classification.
Citation
LeVan, S. L.; Tran, H. C. 1990. The role of boron in flame-retardant treatments. First International Conference on Wood Protection with Diffusible Preservatives : ... Nashville, Tennessee, November 28-30, 1990. Madison, WI : Forest Products Research Society, 1990.:p. 39-41 : ill.
