TB73: Estimating Heat Consumption in Kiln Drying Lumber

This report presents one method for systematically estimating heat consumption in a dry kiln. The basis for evaluating heat use is presented along with a description of the specific elements of heat consumption. All necessary physical relationships are described in detail for those who wish to employ them. One point of interest here is the fact that the system described will readily lend itself to the construction of a mathematical model.https://digitalcommons.library.umaine.edu/aes_techbulletin/1124/thumbnail.jp

TB149: Wood Property-Age Relationships of Natural and Plantation-Grown Red Pine

This study examined changes in specific gravity, modulus of rupture, and modulus of elasticity with age for a natural stand and two plantations. It also examined differences in wood properties between the three stands and the effects of important variables on, and their interactions with, wood properties. Wood property data were obtained from microbending specimens selected at breast height from five trees in each stand.https://digitalcommons.library.umaine.edu/aes_techbulletin/1049/thumbnail.jp

TB104: An Analysis of Moisture Content Variation in Eastern Spruce and Balsam Fir in Maine

This study was undertaken as an attempt to develop some estimate of the characteristic moisture content of green eastern spruce (Picea spp.) and balsam fir (Abies balsame a (L. ) Mill.), employing the methods prescribed under the Maine Weights and Measures Law. Certain procedural factors and conditions of growth were also considered, to evaluate their effect on the moisture content of the wood at the time of harvesting or shortly after cutting.https://digitalcommons.library.umaine.edu/aes_techbulletin/1088/thumbnail.jp

TB152: The Effect of Juvenile Wood on the Properties of Aspen Flakeboard

While the effects of juvenile wood tissue on solid wood products and paper have been known for some time, little information is available regarding its influence on structural flakeboard. Juvenile and mature wood tissue were identified b y their physical and mechanical properties in quaking aspen (Populus tremuloides Michx.). Sections of juvenile and mature wood were separated from 1-foot bolts of aspen. These sections were used to prepare three distinct types of structural flakeboard : juvenile wood-based, mature wood-based, and one formed from an equal mixture of the two. The panels were tested for selected mechanical and physical properties. The juvenile wood-based panels performed significantly better than the mature wood-based in respect to modulus of rupture, thickness swell, and water absorption, while also exhibiting somewhat higher values for modulus of elasticity, internal bond strength, compressive shear strength, and linear expansion. The panels made with a mixture of the two types of flakes did not display some of the poorer characteristics of the mature wood panels.https://digitalcommons.library.umaine.edu/aes_techbulletin/1052/thumbnail.jp

TB61: Properties of Plantation Grown Red Pine Related to Its Utilization

This report describes a study that was conducted to evaluate the static bending and compression parallel to the grain properties evident within and among material from 19 plantation-grown red pine trees, and to determine what effect position in the tree, latewood percentage, fibril angle, specific gravity and rate of growth might have on these mechanical properties. The second phase of the study was conducted concurrently with the first to determine what effect position in the tree and specific gravity might have on the characteristics of red pine Kraft pulp. A third investigation evaluated the effect of three dry kiln schedules on the visual grade characteristics and on the static bending, compression parallel to the grain, shear parallel to the grain and toughness strength properties of plantation-grown red pine.https://digitalcommons.library.umaine.edu/aes_techbulletin/1134/thumbnail.jp

TB127: Age and Thinning Effects on Wood Properties of Red Spruce (Picea rubens Sarg.)

Ten overstory red spruce were selected from a thinned stand and 1 0 from an unthinned stand. Average age of sample trees was approximately 80 years. Specific gravity reached a maximum at age 53 in the thinned stand and age 72 in the unthinned stand, after which it remained relatively constant. Stiffness reached a maximum at ages 35 and 50, and bending strength at ages 41 and 54; both remained relatively constant with further increases in age. Stiffness showed the largest relative difference between juvenile and mature wood, 22%, and specific gravity the smallest difference, 8%. Thinning did not adversely affect any of the properties, even though the width of some growth rings was increased by three to four times. These results suggest that (1) growth of mature red spruce stands can be increased by thinning without affecting wood physical properties, and (2) intensive management practices designed to shorten the rotation age may lead to stands that have not begun to produce mature wood before they are harvested. These short-rotation stands will contain a higher percentage of juvenile wood than stands presently being harvested, which means that pulp yields will decrease and the material will be less suitable for structural lumber.https://digitalcommons.library.umaine.edu/aes_techbulletin/1063/thumbnail.jp

TB139: Stand Age and Density Effects on Volume and Specific Gravity of Black Spruce

Ten dominant or codominant trees were sampled from a 29-year-old black spruce stand, released at age 19, and ten of comparable dbh from a 77-year-old, unthinned stand. A variety of characteristics, including taper, volume, and specific gravity of the bole, as well as the change in specific gravity with age at breast height, were determined for trees from both stands. The older trees had significantly less taper, shorter crowns, approximately 1.9 times more merchantable volume and 10% higher specific gravity. The juvenile period for specific gravity was approximately 60 years. The higher specific gravity and merchantable volume of the older trees resulted in approximately 2.1 times more solid wood in the merchantable bole.https://digitalcommons.library.umaine.edu/aes_techbulletin/1197/thumbnail.jp

The effect of juvenile wood on the properties of aspen flakeboard

While the effects of juvenile wood tissue on solid wood products and paper have been known for some time, little information is available regarding its influence on structural flakeboard. Juvenile and mature wood tissue were identified b y their physical and mechanical properties in quaking aspen (Populus tremuloides Michx.). Sections of juvenile and mature wood were separated from 1-foot bolts of aspen. These sections were used to prepare three distinct types of structural flakeboard : juvenile wood-based, mature wood-based, and one formed from an equal mixture of the two. The panels were tested for selected mechanical and physical properties. The juvenile wood-based panels performed significantly better than the mature wood-based in respect to modulus of rupture, thickness swell, and water absorption, while also exhibiting somewhat higher values for modulus of elasticity, internal bond strength, compressive shear strength, and linear expansion. The panels made with a mixture of the two types of flakes did not display some of the poorer characteristics of the mature wood panels.https://digitalcommons.library.umaine.edu/aes_techbulletin/1052/thumbnail.jp