The vapor-drying process is described briefly and its present status in industry is discussed. Fairly extensive data on the vapor drying of 1-, 2-, and 4-inch Douglas-fir and 2-inch western hemlock lumber are presented. Exploratory work on the vapor drying of redwood, Pacific madrone, red alder and ponderosa pine is...
The increasing volume of young-growth Douglas-fir timber cut in the Pacific Northwest emphasizes the need for more knowledge on the characteristics of lumber sawed from these trees.
The study described here was initiated to learn the extent arid causes of degrade resulting from kiln-drying young-growth Douglas-fir dimension lumber. At the...
The Oregon Forest Products Laboratory was asked in July 1953 by the Oregon Alder and Maple Company, Willamina, to work on the problem of dark stain which developed at sticker crossings in air-drying red alder (Alnus rubra, Bong.) during the summer months.
Previous experience at the Oregon Alder and Maple...
Four charges of S-inch paper roll plugs of Oregon maple were kiln-dried at various temperatures and humidities. The charge with the most desirable combination of short drying time and low degrade was dried to 12 per cent moisture content in lit hours, using a dry-bulb temperature of 160 degrees F...
Checking was influenced b drying conditions. This influence was greatest before average moisture content reached 20 per cent, but tension in surface layers caused checking even below this point.
Neither high initial dry-bulb temperature nor initial conditions of high equilibrium moisture content were conducive to checking.
High temperature and high...
Forced-air drying of lumber is economically feasible as an aid to sawmills without dry kilns. Reduced cost of shipping more than offsets cost of drying with forced circulation of air. Investment in equipment is small.
In the Willamette Valley, forced-air drying probably can be accomplished successfully throughout the year. High...
To test the effects of kiln-drying on strength properties of Douglas fir and western hemlock, temperatures to 230 F, conditions for equilibrium moisture contents of 6 percent and 12 percent, and prolonged heating were investigated.
Prolonged heating and choice of conditions for 6 percent or 12 percent equilibrium moisture content...