Treesearch

Microtomography has successfully been used to characterize loss of structural integrity of wood. Tomographic images were generated with the newly developed third generation x-ray computed microtomography (XCMT) instrument at the X27A beamline at the national Synchrotron Light source (NSLS). The beamline is equipped with high-flux x-ray monochromator based on multilayer optics developed for this application. The sample is mounted on a translation stage with which to center the sample rotation, a rotation stage to perform the rotation during data collection and a motorized goniometer head...

Fiber loading is an environmentally friendly, energy efficient, and economical method for depositing precipitated calcium carbonate (PCC) partly within pulp fibers. Fiber loading can easily be done within the existing pulp processing system. This paper is a review of the process development from bench-scale to industrial-scale demonstrations, with additional experimental results showing the benefit of high consistency and high pH used in fiber-loading processing. Initially increasing the filler level without decreasing paper strength was the objective. Subsequently, substituting low cost...

Past work has shown that the extracellular manganese- dependent peroxidases (MnPs) of ligninolytic fungi degrade the principal non-phenolic structures of lignin when they peroxidize unsaturated fatty acids. This reaction is likely to be relevant to ligninolysis in sound wood, where enzymes cannot penetrate, only if it employs a small, diffusible lipid radical as the proximal oxidant of lignin. Here we show that a non-phenolic b- O-4-linked lignin model dimer was oxidized to products indicative of hydrogen abstraction and electron transfer by three different peroxyl radical-generating...

The production of industrial wood from natural forests is predicted to decline in the future. Factors that will contribute to this decline include changes in land use patterns, depletion of resources in some parts of the world, and the withdrawal of forest areas from industrial production in order to provide for environmental, recreational, and other social needs. There is a shortage of information on the suitability of fiber from many plantation-grown species for alternative composite products. This research was conducted to determine the suitability of plantation-grown Eucalyptus saligna...

We estimated the effectiveness of fiber loading in reducing greenhouse gas emissions for producing lightweight high-opacity newsprint. Fiber loading enhances fiber bonding at increased precipitated calcium carbonate levels without significant loss in Canadian Standard Freeness or additional energy use. We investigated the reduction of greenhouse gas emissions for a hypothetical 600 metric ton/day newsprint mill. The energy reductions responsible for the reduction in greenhouse gases were due to substituting more readily dewatered fiber-loaded precipitated calcium carbonate (FLPCC) for...

For many wood species, the grading of timbers [>76 mm (>4-in.) thick] has not changed in decades. Most timbers are still visually graded by methods that originated in the 1930s. Mechanical grading procedures used to accurately grade 38-mm (2-in. nominal) dimension lumber have not been adapted for use with timbers. Furthermore, the only reliable timber test data available for most softwood species were obtained near the turn of the 20th century, and no test data are available for hardwood timber. The lack of better grading procedures and test data makes it likely that current property...

We estimated the capital effectiveness of fiber loading in regard to producing lightweight high-opacity newsprint. Fiber loading enhances fiber bonding at increased precipitated calcium carbonate levels without significant loss in Canadian standard freeness or additional use of energy. We investigated the return on investment (ROI) for fiber loading precipitated calcium carbonate for a hypothetical 600 metric ton/day newsprint mill. Saving were obtained from substituting lower cost fiber-loaded precipitated calcium carbonate (FLPCC) for higher cost fiber, reducing grammage and drying...

This presentation provides a thought-provoking look at options for utilizing small- diameter wood to help reduce the widespread risk of catastrophic wildfire throughout the West while providing economic recovery of timber-depressed communities and sustaining viable forest products industry. Potentially viable utilization and marketing options are explored and current Forest Service small-diameter utilization research and technology transfer efforts are discussed. Specific points include effective utilization and marketing of underutilized and small-diameter material and evaluating potential...

The oil sorption capacities of cotton fiber, kenaf bast fiber, kenaf core fiber, and moss fiber were compared after refining, extraction, and reduction in particle sizes. The tests were conducted on diesel oil in a pure form. Cotton fiber showed the highest capacity, followed by kenaf core and bast fibers. Wetting, extraction, and reduction in particle size all contributed to the changes in sorption capacity. The most significant change was due to the reduction in particle sizes of cotton and kenaf bast fibers; however, the kenaf core was not affected. Usually, lignocellulosic fibers are...

This paper investigates the relationship between wood pH and the strength properties of fire-retardant-treated (FRT) plywood, as it is affected by fire-retardant (FR) formulations, processing variables, and extended high temperature exposure conditions. The objectives of this study were to (1) identify the effect of post-treatment kiln-drying temperature, followed by high temperature exposure, on wood pH; (2) identify the effect of various mixtures of FR components, followed by high temperature exposure, on wood pH; (3) determine if treatment effects on strength and pH are affected by...