Treesearch

To evaluate the effect of backpriming on in-service performance,hardboard lap siding from one manufacturing plant was exposed on two test buildings in southern Florida for 29 months. The two buildings were identical, except that one had 0.3 m (12-inch) roof overhangs without gutters and the other had gutters but no roof overhangs. Siding installation was the same on both buildings and was essentially as recommended by the manufacturer. Laboratory tests revealed that edge swell and other properties of this particular siding were much better than required by industry standards. With only one...

Polyoxometalates (POMs) are a class of delignification agents that promise to provide the basis for a new closed-mill bleaching technology. The results presented here are based on the use of Na6SiV2W10O40, which is effective in reducing the Kappa number of softwood Kraft pulp from 30 to below 10 with minimal loss in viscosity. A critical part of a viable POM process is the elimination of the organic lignin and carbohydrate-derived fragments dissolved during the delignification. To simulate a closed process, a series of pulp samples were delignified with the same POM liquor. Before each...

This report presents statistical information on production, trade, consumption, and prices of forest products in the United States. Although national statistics are dealt with for the most part, some statistics are given for regions, states, and Canada. The tables presented in this report contain information collected from industry trade associations and government agencies. Some of the tables show data that were derived from mathematical calculations, and some show conversions from different units of measurement. These data are intended for use by anyone associated with the wood using...

Recycled paper fiber recovered from our municipal solid waste stream could potentially be used in structural hardboard products. This study compares strength properties and processing variables of wet-formed high-density hardboard panels made from recycled old corrugated container (OCC) fibers and virgin hardboard fibers using continuous pressure during drying. The results show that panels made from OCC fibers had 3 times the strength and 2 times the stiffness of panels made from virgin hardboard fibers. For commercial hardboard, panels made from OCC fibers had 2.5 and 2 times the strength...

A three-dimensional structural panel, called FPL Spaceboard, was developed at the USDA Forest Products Laboratory. Spaceboard panels have been formed using a variety of fibrous materials using either a wet- or dry-forming process. Geometrically, the panel departs from the traditional two-dimensional flat panel by integrally forming an array of perpendicular ribs and face in one structure. In the literature, significant work has been conducted to model drying of two-dimensional panels, but no known work has been done on such a three-dimensional structure. In order to optimise the drying...

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...