Treesearch

Preliminary figures of wood-based panels consumption in Europe show a small increase in 1999 to 52.1 million m3 a new record level. However, according to the European Panel Federation (EPF), real consumption taking into account particle board stock changes, was higher due to the recovery of markets in the second half of 1999. Particle board is the main panel in Europe with over 67% of total consumption. Consumption of MDF and OSB set record levels. MDF was up 10.7% to 7.14 million m3 and OSB increased by 43% to just under 1 million m3. In North America trends show a continued strong...

Consumption of wood fiber in pulp, paper and paperboard increased in the United States over the past century and is projected to increase well into the next century at a decelerating rate of growth. Harvest of pulpwood on forest land is the single largest source of wood fiber, followed by recycled paper and wood residues. In the past decade, wood residues declined in supply while use of recycled paper increased rapidly. Use of recycled paper is projected to increase more steadily in the future with slower growth in paper recovery for recycling. Harvest of pulpwood on forest land is...

Wet air oxidation (WAO) reactions of cellobiose, phenol, and syringic acid were carried out under mild conditions (155°C; 0.93MPa 02; soluble catalyst, Na5[PV2Mo10O40]). Initial oxidation rates were rapid but decreased to small values as less reactive oxidation products accumulated. Recalcitrant oxidation products were consumed more rapidly, however, if additional cellobiose or phenol was added, a procedure equivalent to recirculation of WAO-reactor effluent. A half-fraction, factorial investigation was used to correlate rate enhancement with individual experimental variables: using a...

The melt viscosities and mechanical properties of 3 different natural fiber-polypropylene composites were investigated. Coir (coconut), jute, and kenaf fibers were compounded with polypropylene at 30% by weight content. A capillary rheometer was used to evaluate melt viscosity. The power-law model parameters are reported over a shear rate range between 100 to 1000 s–1. Effects on melt viscosity with the use of a coupling agent and different fiber types were also evaluated.

Sisal fibers and finely powdered high-density polyethylene were surface functionalized using dichlorosilane (DS) under R-F plasma conditions to improve interfacial adhesion between the two dissimilar substrates. The functionalized polyethylene (70%) and sisal (30%) were compounded on four different ways using thermokinetic mixer and injected molded into composites specimens for test. Some improvements in mechanical properties of the composites due to the plasma treatments were achieved. Scanning Electronic Microscopy (SEM) data indicated that some compatibilization of the two plasma...

In recent years, a number of clear wood finishes have been developed that protect wood while accentuating its natural beauty. The focus of this publication is on those finishes having little visible pigment. In some cases, the pigments are included but are finely ground to create a coating that is transparent to visible light. Most natural clear wood finishes are designed to protect and beautify wood. Although this may sound simple, manufacturer’s claims that products protect, preserve, seal, last longer, work better, and spread farther than competitors’ products can be confusing. In fact,...

The ultimate goal of the US Postal Service (USPS) Environmentally Benign Stamp Program is to develop stamp adhesives that can be removed by unit operations found in recycling mills. The maintenance of final product quality specifications for a recycling mill while loading the feedstock with a significant quantity of adhesive is the criterion for success of this program. However, since it is neither prudent nor cost-effective to test all experimental adhesive materials at mill-scale, we have developed laboratory-scale (360 g pulp) and pilot-scale (112 kg pulp) protocols for testing adhesive...

Existing log grading procedures in the United States make only visual assessments of log quality. These procedures do not incorporate estimates of the modulus of elasticity (MOE) of logs. It is questionable whether the visual grading procedures currently used for logs adequately assess the potential quality of structural products manufactured from them, especially those in which MOE is of primary concern. The purpose of this study was to investigate the use of stress wave NDE techniques to sort red maple logs for the potential quality of lumber obtained from them. One hundred seven red...

Fast curing phenol-formaldehyde (PF) resins could potentially allow wood to be bonded at higher moisture contents and at lower press temperatures than those currently used commercially. Recent reports in the literature have shown that the addition of esters, lactones, or organic carbonates increased the curing rate of PF resins. Several mechanisms have been proposed to ex-plain the accelerated cure. The PF model compounds 2-and 4- hydroxymethyl phenol (2-HMP and 4-HMP) were reacted in alkaline conditions at 20°C, with and without cure accelerators, such as ethyl formate, propylene carbonate...

The USPS Image Analysis (IA) protocol recommends the use of hydrophobic dyes to develop contrast between pressure sensitive adhesive (PSA) particles and cellulosic fibers before using a dirt counter to detect all contaminants that have contrast with the handsheet background. Unless the sample contains no contaminants other than those of interest, two measurement steps are required: before dying to detect dirt and after dying to detect both dirt and dyed contaminants. The difference between these two measurements can be used to estimate the level of dyed contaminants present. To complement...