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The results of this study showed that the same relative reductions in thickness swelling (TS) previously obtained with steam-injection-pressed (SIP) resinless mats are also obtained in boards bonded with 3% isocyanate resin. Reductions in thickness swelling were proportional to steam time and pressure. Thickness swelling of 40% measured in conventionally pressed boards following a vacuum-pressure-soak treatment was reduced to 25% in a board exposed to 20 sec of steam at 600 kPa and to 6% in a board exposed to 40 sec of steam at 1,900 kPa. We believe that the reductions in thickness...

A physical, yet analytical, model of fire growth has predicted flame spread and rate of heat release (RHR) for an ISO9705 test scenario using bench-scale data from the cone calorimeter. The test scenario simulated was the propane ignition burner at the comer with a 100/300 kW program and the specimen lined on the walls only. Four phases of fire growth were simulated. The first two phases, the wall ignition and upward flame spread, have separate physical formulations. Some empiricism, however, was required to predict the phases of lateral and downward flame spread. Two groups of materials...

In this study, the microstructure of injection-molded polypropylene reinforced with cellulose fiber was investigated. Scanning electron microscopy of the fracture surfaces and X-ray diffraction were used to investigate fiber orientation. The polypropylene matrix was removed by solvent extraction, and the lengths of the residual fibers were optically determined. Fiber lengths were reduced by one-half when compounded in a high-intensity thermokinetic mixer and then injection molded. At low fiber contents, there is little fiber orientation; at high fiber contents, a layered structure arises....

A program was undertaken at the Forest Products Laboratory in conjunction with the American Society for Testing and Materials (ASTM) to develop guidelines for a credible accelerated photoaging protocol for printing and writing papers. In support of this, indepth studies of photodegredation were undertaken in sufficient detail to establish the validity of the protocol. Photoaging was carried out in two different environments. The first was intended to simulate natural aging conditions with exposure to artificial and daylight illumination. The second environment provided higher photon flux...

Removal of pressure sensitive adhesives (PSAs) from recovered paper is a major problem facing the paper recycling industry. As a result of a United States Postal Service (USPS) initiative, which currently purchases about 12% of domestic PSA production, a team was formed consisting of representatives from the USPS, the Forest Products Laboratory, Springborn Testing and Research, paper recovery companies, paper recyclers, adhesive manufacturers, and chemical suppliers. This large team of cooperators has the common goal of formulating PSAs that can be efficiently removed during the fiber...

This paper is an overview of what we know about occurrence of wood decay above ground within buildings. It presents information concerning under what conditions decay may become established. In laboratory tests involving optimum moisture and temperature conditions for decay fungi, and direct contact with large quantities of specific well-developed decay fungi, substantial decay in small specimens of untreated wood of nondurable species can occur in a few weeks. The simultaneous occurrence of optimum conditions for decay and high degree of inoculation with mature decay fungi is probably...

On account of its distinctive features, Setchellanthus cannot be included within any of the families of glucosinolate-producing plants. Features unknown in any of these families include abundant vasicentric tracheids, abaxial axial parenchyma, and only short uniseriate rays (composed of upright cells) in wood: and the presence of wide-helix tracheary elements in leaves. Wood offers the greatest number of phyletically significant features, and wood of Capparaceae offers many similarities, although the wood of Helianthemum (Cisraceae) is even more like that of Setchellanthus. Despite the...

As a result of a United States Postal Service (USPS) initiative, a work team consisting of the USPS, the Forest Products Laboratory (FPL),Springborn Testing and Research (STR), and industry representatives wasformed. The industry representatives include papermakers, paper recyclers,paper collectors, equipment manufacturers, paper users, and adhesive and chemical suppliers. The objective of the work team is to develop new and innovative solutions to the problems associated with recycling recovered paper containing pressure-sensitive adhesives (PSAs). Initial open discussions were held at...

As a result of a United States Postal Service (USPS) initiative, a work team was formed consisting of representatives from USPS, Forest Products Laboratory (FPL), Specialized Technology Resources, Inc. (STR), and industry. The industries represented included papermakers, paper recyclers, paper collectors, equipment manufacturers, paper users, adhesive manufacturers and chemical suppliers. The objective of the work team is to develop new and innovative solutions to problems associated with recycling paper containing pressure sensitive adhesives (PSAs). Based on criteria developed by the...

In the area of photoyellowing of mechanical pulps, recently obtained experimental evidence has shown that hydroquinone/p-quinone redox couple is present in lignin-rich mechanical pulps. It was also noted that compared to a control pulp the concentration of p-quinones was significantly higher in a photoyellowed pulp. Under ambient conditions, upon exposure to light, the existent pulp hydroquinones were converted to p-quinones. To further investigate the importance of hydroquinone/p-quinone redox couple in photoyellowing, studies of methylhydroquinone and methyl-p-quinone were carried out....