Treesearch

The pertinent literature has been reviewed, and the apparent effects of selected processing parameters on the resultant particleboard properties, as generally reported in the literature, have been determined. Resin efficiency, type and level, furnish, and pressing conditions are reviewed for their reported effects on physical, strength, and moisture and dimensional properties. A serious deficiency in the research appears to be lack of consideration of the within-panel density gradient and its effects on physical properties.

This literature review was conducted in connection with a study on heat transfer in frozen logs. A combination of data by two researchers on specific heat and thermal conductivity and diffusivity in the radial direction of wood, at various temperatures and moisture contents, is discussed and compared with data from other sources. Limited information found for the tangential and longitudinal directions is also included in the report. In addition, a data set of average thermal diffusivities in the radial direction of wood is provided for temperature intervals involving complete thawing.

This report answers the questions most often asked of the Forest Service on the protection of log cabins from decay, and on practices for the exterior finishing and maintenance of existing cabins. Causes of stain and decay are discussed, as are some basic techniques for building a cabin that will minimize decay. Selection and handling of logs, their preservative treatment, construction details, descriptions of preservative types, and a complementary bibliography are also included.

A sawing system that reduces warp may be the key to utilize yellow-poplar for studs.

Based on laboratory performance with a number of fire-retardant chemicals, disodium octaborate tetrahydrate-boric acid and dicyandiamide-phosphoric acid-formaldehyde were selected for treating fiber and making 4 foot by 8-foot dry-formed hardboards on a commercial production line. The boards were evaluated for performance under exposure to fire, strength, dimensional stability. and durability. Both treatment systems produced boards that met the acceptance flamespread criteria for Class B material. In a 25-foot tunnel furnace. The disodium octaborate tetrahydrate-boric acid gave the lowest...

Under a system that permits mass screening of mycelia within bands of the visible spectrum, fruit bodies initiated and developed in two light bands (387-400nm and 425-430nm) in axenic culture. Either or both of these light bands will trigger fruitbody initiation at as low an energy level as 0.2 K (1 K = 1,000 microwatts/cm2). Maturation of sporocarp and hymenium requires an energy level of no less than 1.8 K in at least one of these two bands, and consistent production of mature sporocarps requires 3.0 K at one or both peaks. The presence or absence of energy in other wavelengths of the...

Determination of the racking strength of wails, which is a measure of a building system’s ability to resist wind loads, has generally been limited to performance testing. Although a standard test method exists, deviations have often been made in speed of testing and panel configuration. The purpose of this study was to determine the relative effect of some of these deviations on test results. In addition, the racking strength of wails with let-in corner braces, which forms the basis for acceptance criteria, was evaluated. Strength of wails with let-in corner braces, but without horizontal...

Experimentally and commercially produced laminated M-19 crossarms were tested by standard Rural Electrification Administration (REA) crossarm tests. The laminated crossarms, produced by laminating veneer and by laminating solid-sawn dimension stock, generally performed satisfactorily according to REA specified standards. Materials tested are described and results on standarized tests are summarized. The objective of this work was to provide indications of performance trends. Statistically valid performance comparisons between the materials tested were not possible because of the limited...

This Note illustrates how a sales summary can be modified to separately identify changes in sales realization caused by changes in market prices and by changes in the product mix sold. With this information, a sales summary can become a helpful record to gage effects of past production and marketing decisions.

Seven different adhesives were evaluated for durability as plywood adhesives by exposing panels and shear-test specimens to weathering at the Madison exposure site for nearly 8 years. Wet-strength loss and wood-failure changes were measured as a function of exposure time. The method of exposure accelerated the degradation that would have resulted from exposure in most service environments. Results were compared qualitatively with the information obtained by accelerated aging in the laboratory and analyzing wet strength loss as a rate process. The rapid, initial strength loss that had been...