Semi chemical pulping processes, using both acid and neutral sulfite liquors, were ap!)lied to the following six Arkansas Delta hardwoods: black willow, southern cottonwood, American elm, sugarberry, green ash, and bitter pecan. Pulping conditions for yields of 75 to 80 percent were determined and the properties of both the pulps...
Hardwoods, including aspen, comprised 22 percent of the pulpwood. received in the New York and New England States pulp mills in 1944 when war-time conditions favored the use of all available wood. The denser hardwoods alone, however, amounted to only 9 percent of all the pulpwood, and this value is...
The mold resistance of fiberboard has been studied to provide a basis for recommendations on the relative merits of various types of commercial and of experimental fiberboards. The experimental fiberboards were prepared. by the Division of Pulp and, Paper of the Forest Products Laboratory.
The breaking radii of variously discolored veneers of six different hardwood species were small enough, for most of the discolorations, to indicate that such veneers can be used successfully on members having curved surfaces. When expressed in terms of the minimum radius of curvature attained without fracturing, the breaking radius...
A survey was made in Oregon and Washington of the discoloration occurring in noble fir and Western hemlock wood, and the present data are presented as an aid in the inspection of these woods for aircraft and other high-grade lumber.
Recommendations, based on strength tests of similar discolorations in spruce...
Wood joints properly made with protein glue should last indefinitely under dry conditions. However, under moist conditions some glues are subject to the actions of micro-organisms and chemical hydrolysis. In previous work the action of bacteria has been discounted as the cause of delimitation of casein glued plywood in the...
A survey was made of the discolorations occurring in Sitka spruce wood, and toughness tests were made on specimens that included discolorations of unknown or doubtful significance.
Intelligent selection of wood for the job it is to do is particularly essential during wartime conditions of scarcity when supplies must be conserved and useful life extended. One way of increasing the service life of wood exposed to damp conditions is to select material that has a high natural...
No one prefers green lumber. Its higher shipping weight, poorer nail-holding power, and shrinkage after fabrication are well known, but the present pressure for deliveries results in much of it being accepted. Another major objection to lumber shipped green is that is may be damaged bu wood-decaying fungi, either in...
American beech (Fagus grandiflora) is now, and probably will be, increasingly used to replace yellow birch for aircraft construction. Even though it is one of the principal components of the northern hardwood forests of North America, study of the characteristics and properties of its wood has been neglected to the...
The rat caused by Pozia incrassata (Berk, and Curt.) Burt (sometimes erroneously called "dry rot") in individual cases is the most destructive of the building decays in the warm coastal portions of the United States and the South. The fungus usually attacks rapidly and may cause damage necessitating extensive repairs...
Dipping or spraying green lumber with stain control chemicals has been reported recently as valuable for delaying or preventing stain and decay infection in bulk-piled lumber, as well as in the air-seasoning piles for which such treatments were originally developed. But it should be kept in mind that if lumber...