Treesearch

Wood-plastic composites are being examined for a greater number of structural-type applications that may be exposed to different environments, some of them adverse. This paper discusses the influence of moisture absorption on the mechanical proper-ties of wood flour-polypropylene composites. Composites filled with 20% or 40% wood flour (by weight) were placed in different environments, removed periodically, and tested for moisture content and mechanical properties. The composites filled with 20% wood flour (20% WF) absorbed moisture in all the environmental exposures, but no significantdegr...

This chapter on wood adhesives includes: 1) Classification of wood adhesives 2) Thermosetting wood adhesives 3) Thermoplastic adhesives, 4) Wood adhesives based on natural sources 5) Nonconventional bonding of wood 6) Wood bonding.

Mechanical, chemical, and light microscopic methods were used to observe wood cell wall changes during colonization by Ceriporiopsis submervispora. Maximum crushing load, dynamic mechanical analysis (DMA), and quantitative Simon’s staining were found to be the most useful methods for tracking biopulping action. MOE and loss modulus trended downward within 2 days of inoculation, even though few cells were colonized by that time. Quantitative Simon’s staining results were highly correlated with refiner energy savings.

Some instances of severe warping of siding treated with a commercial waterborne preservative have been reported to the authors. We investigated this problem by evaluating 25mm-, 51 -mm-, and 102-mm- (1-, 2,- and 4-in.-) thick chromated copper arsenate (CCA) treated No. 1 southern yellow pine lumber shipped from three suppliers to a secondary manufacturer in Louisiana. The moisture content (MC), CCA retention, and adsorption/ desorption ratio was determined for specimens cut from the lumber. For all lumber thicknesses and target retention levels, including untreated wood, the MC of many...

This is the second in a series of reports on the erosion rates of wood exposed outdoors near Madison, Wisconsin. In the work reported here, the erosion rates of earlywood and latewood were determined for smooth-planed vertical-grained lumber for an exposure period of 14 years. The specimens were oriented vertically, facing south; erosion was measured annually for the first 6 years and biannually the remainder of the exposure. Wood species were ponderosa pine, lodgepole pine, Engelmann spruce, western hemlock, and red alder. Large differences were observed between earlywood and latewood...

A new noninvasive technique has the potential to assess the in-place stiffness of timber floors.

The new cobalt substituted-polyoxometalate K7[CoAlW11O39]•15H2O and the simple CoCl2•6H2O salt are efficient catalysts for peroxynitrite decomposition. These compounds also catalyze the oxidation of ascorbic acid and the nitration of phenol by peroxynitrite.

We outline the steps that would permit a statistician to produce special purpose linear model routines through the use of high quality public domain numerical analysis software.

This report provides general and statistical information on forests products markets in terms of production, trade, consumption, and prices. The current state of the United States economy is described. Market developments are described for sawn softwood, sawn hardwood, softwood log trade, wood-based panels, paper and paperboard, fuelwood, and forest product prices. Detailed information and projections for the year 2002 are presented.

In this study, a wood preservative containing active ingredients of 43.5% borax and 3.1% copper hydroxide was evaluated in soil-block tests in accordance with AWPA E10. Results suggested thatthe copper hydroxide was not contributing to fungal toxicity at preservative threshold levels. Thresholds determined for this preservative were very close to those previously reported for sodium borate. For this preservative,the soil- block test results in this study were less effective than field test results.