Ultrasonic wave attenuation and velocity in the transverse direction were used to detect defects in ponderosa pine (Pinus Ponderosa) lumber previously dried from green to 9% moisture content. After ultrasonic testing the boards were visually inspected for defects and classified according to the defects present. An ANOVA with Bonferroni pairwise...
Large inelastic strain occurs inside a piece of lumber during drying. The strain consists of several components such as elastic, plastic, creep, shrinkage and mechano-sorptive effect. The mechanical behavior of the whole board during drying is determined by the behavior of individual strain components and their interactions. Whereas limited investigations...
A mathematical and then a numerical model were developed for simulating a convective batch lumber drying process. The model incorporates mass and heat transfer relationships within the lumber stack, as well as thermodynamic properties of the wood and drying air. It takes into account a change of air properties along...
A Life Cycle Assessment (LCA) of the production of poplar biomass grown under four management conditions in the Pacific Northwest (PNW) of the U.S.A. was conducted. While the extraction of fossil fuels and the subsequent generation of energy have environmental impacts, the alternative of extracting poplar biomass also has impacts...
The fixed bed drying of western hemlock and Douglas-fir biomass particles at temperatures ranging from 50°C to 200°C and air velocities from 0.3 to 0.9 m/s was investigated. The objectives were to describe the drying characteristics of the particles, fit a model for thin-layer drying, and develop and test a...
The advantages of high-temperature drying are faster drying, reduced inventory, reduced energy requirements, and reduced equilibrium moisture content. However the disadvantages are higher initial costs of the kiln, greater power needs, knot dropout, and reduction in some strength properties. The latter was the subject of this study. Three hundred pieces...
Sonic, boiling, and steaming pretreatments were analyzed to determine their
effects on radial and longitudinal liquid permeability, drying rate, and the overall
dimensional change of Pacific madrone during kiln drying. Twelve days of drying at
temperatures ranging from 110 °F to 140 °F and seven days of equalization were
used...
As lumber producers are faced with a diminished and increasingly expensive raw
material, the need to maximize resource recovery will increase. Trim-ends (particularly
from waned boards) often contain some of the highest quality wood in any given log
and lack functionality only in length. This waste, traditionally chipped for pulp,...
This study was to investigate effects of growth rate
and cambial age on properties of wood from two increasingly
used hardwood species, red alder (Alnus rubra Bong.) and
Oregon white oak (Quercus garryana Dougl.), for better
understanding factors affecting wood quality in hardwoods.
Thirty 7-year-old trees grown at widely varying...
