Treesearch

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...

The interest in lignocellulosic fiber composites has been growing in recent years because of their high specific properties. In this work, a new technique was used to prepare specimen to observe the transcrystalline zones in kenaf fiber-polypropylene composites. A maleated polypropylene (MAPP) coupling agent was used to improve the stress-transfer efficiency in the composites. Transcrystallinity was observed for both the uncoupled and coupled composites, although the rate of growth was higher for the coupled composites. Dynamic mechanical spectroscopy was used to observe the relaxations of...

Release liner waste material is found in post-consumer waste streams and is also a significant component of the preconsumer waste stream generated in the manufacturing of adhesive products. To date, very little has been reported pertaining to the behavior of release liner in paper recycling. In this study, the effect of the release liner material on the behavior of adhesive contaminants during laboratory pulping was investigated by dyeing the adhesives and the release liner with a blue dye and performing image analysis. The presence of release liner in the furnish caused a decrease in the...

Thus, a need arose for the development of surface finishes for CCA-treated wood that could address the special requirements of this substrate and provide protection against the ravages of water, sunlight, mildew, and other aspects of weathering and wear. Initially, this need was not addressed, most wood preserving companies had little expertise in surface finishes and most coatings manufacturers saw the CCA-treated lumber market as too narrow to justify major product development efforts. As a consequence, "all-purpose"-type products were sometimes shoe-horned into the CCA deck category...

The weakness of existing relationships correlating off-axis modulus of elasticity E q to shear modulus G 12 for wood composite panels is demonstrated through presentation of extensive experimental data. A new relationship is proposed that performs better than existing equations found in the literature. This relationship can be manipulated to calculate the shear modulus G 12 of orthotropic specimens such as wood-based panels solely from off-axis tension (or compression) tests. The proposed relationship reduces to classical theory for the isotropic case. In all cases tested, the newly...

Considerable interest has been generated in the use of lignocellulosic fibers and wastes (both agricultural and wood based) as fillers and reinforcements in thermoplastics. In general, present technologies limit fiber loading in thermoplastics to about 50% by weight of fiber. To produce high fiber content composites for commercial use while maintaining adequate mechanical properties requires innovative processing techniques. A new technique has been developed that allows very high fiber loading. We have processed composites up to about 95 % by weight of fiber in polypropylene (PP). The...