Treesearch

Calocarpum, long maintained as a distinct taxon, is now generally considered as a synonym of Pouteria. The wood anatomy is quite different from Pouteria (sensu stricto) and the author is of the opinion that reduction to synonomy is not justified. The anatomical evidence supports the treatment of Calocarpum by the monographer Charles Baehni.

Specimens of phenolic-bonded flakeboard, vertical-grain southern pine and Douglas-fir, and marine-grade Douglas-fir plywood were exposed to four accelerated aging situations. These consisted of: 1) Multiple cycles of boiling and elevated-temperature drying, 2) multiple cycles of vacuum- pressure soaking and intermediate-temperature drying, 3) the six-cycle ASTM D-1037 exposure and, 4) continuous exposure to weathering at the Madison, Wis. site. Thickness change and bending strength, bending stiffness, and internal bond strength retention were measured after various numbers of exposure...

Research file data have been successfully retrieved at the Forest Products Laboratory through a high-speed cross-referencing system involving the computer program FAMULUS as modified by the Madison Academic Computing Center at the University of Wisconsin. The method of data input, transfer to computer storage, system utilization, and effectiveness are discussed. Preliminary results indicate that the system is readily usable by either on-line or batch processing, resulting in minimum return of results of about 1/2 hour and a maximum wait of 24 hours. The vocabulary method of single keywords...

Results are reported for an assessment of methods for predicting strength of wood, wood-based, or related material. Research directly applicable to nondestructive strength prediction was very limited. In wood, strength prediction research is limited to vibration decay, wave attenuation, and multiparameter "degradation models." Nonwood methods with potential application to wood include spectral response and techniques based on the ratio of energy dissipated per bending cycle and bending elastic energy at maximum amplitude. Conclusions drawn summarize the current status of nondestructive...

The ASTM standards for establishing clear wood mechanical properties and for deriving structural grades and related allowable properties for visually graded lumber can be confusing and difficult for the uninitiated to interpret. This report provides a practical guide to using these standards for individuals not familiar with their application. Sample stress derivations are presented to supplement the text.

The Forest Products Laboratory manufactured and assessed the performance of 4- by 8-foot structural flakeboard panels from Douglas-fir forest residues after target performance goals were developed. The 42 pcf, three- layer boards were 1/2 inch thick with high quality disk cut flakes for the faces and lower quality flakes processed through a ring flaker in the core. More than 200 panels were produced. Basic mechanical and physical properties were evaluated, as well as durability and performance under concentrated and impact loading, racking strength of wall and floor sections, and fire...

Flake geometry, flake quality, flake alignment, average density, density gradients, layer thicknesses, and resin content were factors considered in determining the final construction details on structural flakeboards made from 1) western softwoods and 2) southern hardwood residues. After making compromises between board properties, a three-layer design was recommended for both board types. Long, thin face flakes enhanced bending properties while thick core flakes maximized internal bond strengths. The lower compaction ratio associated with high-density hardwood species restricted the range...

The Tennessee Valley Authority, in cooperation with the U.S. Department of Agriculture and the Forest Products Research Society, is preparing three slide-tape presentations to help people evaluate wood- and bark fueled boiler systems as alternatives to ones using oil, gas, or coal. The first two presentations cover equipment selection and estimation of fuel values; the third describes procedures for evaluating financial aspects. This report is the basis for the third slide-tape presentation. It can be used as a complement to the audiovisual program, or by itself as a guide to analysis of...

Trends of wood use in the furniture and fixtures industry are examined. Wood consumption statistics from the 1972 Census of Manufactures are used to update prior Forest Service surveys, and separate estimates are made for 1977 consumption. A methodology for making up-to-date estimates of wood usage is also presented.

The results of this investigation showed that physical properties of sheets made from hardwood fiber are very dependent upon fiber morphology. Chemical variation of pulp fibers did not exhibit an influence on sheet strength. Of the morphological characteristics investigated, those contributing the most were fiber length, L/T ratio, and fibril angle. Hardwood fines (parenchyma cells) were detrimental to bursting and tensile strength. Vessel elements, in amounts found originally in typical hardwood furnishes, had no effect on tensile strength.