Treesearch

The durability of preservative-treated stakes of second-growth Coastal Douglas-fir was evaluated in a field plot in northern Queensland, Australia. Results from this field trial indicate that second-growth Douglas-fir can be treated with preservatives to meet Australian standards and will provide long-term durability in adverse environments. Data presented indicate that within a 5-year time frame, the importance of minimum penetration parameters decreases as retention increases.

Published data on estimated air drying times of lumber are of limited usefulness because they are restricted to a specific location or to the time of year the lumber is stacked for drying. At best, these estimates give a wide range of possible times over a broad range of possible locations and stacking dates. This report describes a method for estimating air drying times for specific locations by optimizing a drying simulation using existing experimental air drying times for northern red oak, sugar maple, American beech, yellowpoplar, ponderosa pine, and Douglas-fir. The results are...

In recent years, the performance of copper naphthenate as a wood preservative has been in question. To understand the varying results of copper naphthenate in preventing wood decay, a closer look at eight naphthenic acid (NA) supplies was undertaken. Initial studies of NA samples from individual suppliers revealed large differences in chemical composition and wood preservation ability. Samples were rated from best to worst determined by percent weight loss due to fungal activity. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that one of the intermediate quality wood...

Chemical data pertinent to most-recently developed POM delignification systems will be presented. These data will be used to demonstrate the fundamental basis for the stability, self-buffering properties, versatility and high selectivity of these systems when used in combination with oxygen to convert native or residual lignin in wood or wood-pulp fibers to CO2 and H2O.

This paper has been prepared in order to discuss Fiber Loading™ for lightweight, high-opacity bible paper. Incorporating fillers within pulp fibers has been subject to research since 1960 (Green et al. 1962, Scallan et al. 1985, Allen et al. 1992). Fiber Loading™ is a method for manufacturing precipitated calcium carbonate (PCC) directly within the pulp processing system. The Fiber Loading™ process results in fiber loaded precipitated calcium carbonate (FLPCC™) being partly deposited both within the fiber on the fiber walls and in between the fibers, targeting replacement of cellulose...

Low-grade wastepapers and paper mill sludges can be extruded to form composite materials that can be used like fiberboard and hardboard.

Warp in lumber is a common problem that occurs while lumber is being dried. In research or other testing programs, it is sometimes necessary to compare warp of different species or warp caused by different process variables. If lumber dimensions are not the same, then direct comparisons are not possible, and adjusting warp to a common dimension would be desirable so that these comparisons are possible. In this report, two methods of adjusting warp to different dimensions are developed2one based on the geometry of bow and crook and another based on the geometry of twist. These methods...

One of the most, if not the most, efficient methods of extending our existing forest resource is to prolong the service life of wood currently in-service by using those existing structures to meet our future needs (Hamilton and Winandy 1998). It is currently estimated that over 7 x 109 m3 (3 trillion bd. ft) of wood is currently in service within the United States of America (PATH 1999). Research programs throughout North America are increasingly focusing on understanding and defining the salient issues of wood durability and by maintaining and extending the serviceability of these...

Severely weathered window units were used to test various restoration methods and pretreatments. Sanded and unsanded units were pretreated with a consolidant or water repellent preservative, finished with an oil- or latex-based paint system, and exposed outdoors near Madison, WI, for five years. Pretreatments were applied to both window sashes (stiles and rails) and sills. In most cases, pretreatment with consolidants was detrimental to the finish. These pretreatments generally caused more flaking and cracking of the paint compared with that of untreated controls or penetrating water-repell...

Timber bridges provide an economical alternative to concrete and steel structures, particularly in rural areas with light to moderate vehicle traffic. Wooden components of these bridges are treated with chromated copper arsenate type C (CCA), pentachlorophenol, or creosote to prolong the life of the structure from a few years to many decades. This results in reduced transportation infrastructure costs and increased public safety. However, the preservative used to treat the wooden components in timber bridges is lost to the environment in small amounts over time. This report describes the...