Treesearch

Lignin degradation by the white rot basidiomycete Phanerochaete chrysosporium involves various extracellular oxidative enzymes, including lignin peroxidase, manganese peroxidase, and a peroxide-generating enzyme, glyoxal oxidase. Recent studies have suggested that laccases also may be produced by this fungus, but these conclusions have been controversial. We identified four sequences related to laccases and ferroxidases (Fet3) in a search of the publicly available P. chrysosporium database. One gene, designated mco1, has a typical eukaryotic secretion signal and is transcribed in defined...

In this research we experimented with a new and rapid way of analyzing wood. Near Infrared (NIR)spectroscopy together with multivariate analysis is becoming a widely used technique in the field of forest products especially for property determination and is already firmly established in the pulp and paper industry. This method is ideal for the chemical analysis of wood, and therefore preservative-treated wood. Several commercially treated deckboards were obtained for this study: CCA/Hem-Fir; CCA/Eastern Hemlock; ACZA/Douglas Fir and ACQA-Hem-Fir. They were milled and scanned with a NIR...

In this paper we introduce a new technology based on a mild chemical pretreatment process prior to mechanical pulping. Chips are treated with a dilute solution of oxalic acid (OA) for only 10 minute at 130°C, in a typical example. The properties of the pulp produced by this OA process are quite different from those obtained via conventional chemical pretreatments, providing a much more valuable pulp, and at higher yields. Refining results obtained at the Andritz Pilot Plant in Springfield, Ohio show an outstanding combination of strength improvements, energy savings, and shive and triglycer...

The biopulping process for treating wood chips prior to mechanical pulping has been scaled up through an extensive development program and has been demonstrated at 50 ton semicommercial scale. Detailed engineering analyses and design studies have been performed for full production-scale mill implementation, and the technology is ready for commercial use. This paper will summarize the 50 ton pilot scale equipment constructed to allow in- mill evaluation tests, and design studies for commercial scale implementation of biomechanical pulping. Economic evaluation of the process will be presented...

Altering the surface properties of pulp can enhance binding, increase paper strength, and decrease the cost of fiber. In this study, we modified lignocellulosic materials (bark and pulp) with laccase and selected substrates to change the nature of the pulp surface. Modified pulps were evaluated by the amount of methylene blue (a cationic dye) that would bind to the pulp and the acid–base and dispersive results of inverse gas chromatography (IGC) analysis. Combinations of laccase and substrates that altered various surface properties of the pulp were determined. Methylene blue binding...

This report provides documentation and user information for FPL-PELPS, a personal computer price endogenous linear programming system for economic modeling. Originally developed to model the North American pulp and paper industry, FPL-PELPS follows its predecessors in allowing the modeling of any appropriate sector to predict consumption, production and capacity by technology, and trade within or among several regions or countries. The theoretical structure is that of spatial equilibrium modeling under competitive market assumptions. This report contains a mathematical description of the...

Engineered wood products, such as oriented strandboard, laminated veneer lumber, and other composite wood products, are being used more often in construction. This includes use as rim boards, which are the components around the perimeter of a floor assembly. This situation has increased the need for information about the fire resistance of these products. In this study, we evaluated different engineered wood products for fire resistance using both the ASTM E119 standard for fire exposure and a modified time-temperature curve. We looked at unprotected, gypsum-board-protected, and double...

The traditional method of measuring log volume in North America is the board foot log scale, which uses simple assumptions about how much of a log's volume is recoverable. This underestimates the true recovery potential and leads to difficulties in comparing volumes measured with the traditional board foot system and those measured with the cubic scaling systems used in most of the world. The relationships among these different scaling systems vary systematically with log diameter, as well as length, taper, defects, and measurement and utilization conventions. As average log size has...

Because dense stands of softwood trees are causing forest health problems in the western United States, new ways to use this material need to be found. One option is to use this material as logs rather than sawing it into lumber. For many applications, logs require some degree of drying. Even though these logs may be considered small diameter, they are large compared with the thickness of typical lumber, and they may require uneconomically long kiln drying times. Air drying is a logical alternative to kiln drying, but the variables involved make estimating air drying times difficult. In...

To restore and maintain forest ecosystem health and function in the western interior of the United States, many small-diameter stems need to be removed from densely stocked stands. In general, these materials are underutilized. Information on the properties of these resources is needed to help forest managers understand when timber sales are a viable option to accomplish ecosystem management objectives. Providing proof that this small-diameter material yields quality pulp would help increase its value and therefore help remove it from the forest. This study examines the acceptability of...