Treesearch

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...

This paper compares the Iosipescu shear test to its derivatives: the Wyoming, FPL, and Idaho shear tests.

Beetle-killed spruce can be used as a fiber source for papermaking. The presence of sap rot is a key indicator of pulpability, but other factors may also be important.

Machine lumber grading has been applied in commercial operations in North America since 1963, and research has shown that machine grading can improve the efficient use of wood. However, industry has been reluctant to apply research findings without clear evidence that the change from visual to machine grading will be a profitable one. For instance, mill managers need guidelines on machine grading. This report seeks to document such guidelines so that lumber mills can determine the feasibility of machine grading for their products. The first part of this report discusses the principles of...

Log-sort yards provide better utilization and marketing with improved value recovery of currently available timber resources in North America. Log-sort yards provide many services in marketing wood and fiber by concentrating, merchandising, manufacturing, sorting, and adding value to logs. Such operations supply forest products firms with desired raw materials, which helps improve a company’s bottomline by reducing the number of marginal logs processed. Successful log-sort yards are self- sufficient and have a good business plan, well-established markets, and a steady supply of wood....

This presentation discusses a success story of cooperative research and development (R&D) and commercialization of ultrasonic detection technology for locating internal defects in lumber. The R&D work described in this paper is the result of a unique federal laboratory and private sector partnership between the USDA Forest Service, Forest Products Laboratory (FPL) and Perceptron, Inc., a manufacturer of scanning systems for the forest products industry. Efforts by research engineers at the FPL on applying ultrasonic nondestructive evaluation (NDE) methods proved successful in laboratory...

A series of batch isotherm tests was performed with alfalfa and juniper fibers to evaluate the effectiveness in filtering toxic heavy metals from stormwater. The adsorption of the heavy metal ions on the alfalfa and juniper fibers was strongly dependent on the equilibrium pH value of the solution. The change in sorption rate over time showed that two different sorption processes occurred a fast ion exchange followed by a chemisorption. Heavy metals were less sorbed when they are in solution together than when they exist alone in solution; however, the total adsorptive capacity of the...