Grade Wood Research Articles

Improvement of paper properties by impregnation in cellulose derivative solution. 1. Cellulose acetate solution

AbstractPaper sheets prepared from bleached bagasse and paper grade wood pulp were impregnated in a cellulose acetate solution. After drying the prepared samples were cured at 100°C or 140°C. The measured improvement of the mechanical properties of the treated samples depends on time and concentration of the dipping bath and on the curing conditions.

Improvement of paper properties by impregnation in cellulose derivative solution. 2. Carboxymethyl cellulose solution

AbstractPaper sheets prepared from bleached bagasse and paper grade wood pulp were impregnated in a carboxymethyl cellulose solution. After drying the prepared samples were cured at 100°C or 140°C. The measured improvement of the mechanical properties of the treated samples depends on time and concentration of the dipping bath and on the curing conditions.

Parameters Influencing Behavior of Diaphragms

This paper presents a theoretical study of glue laminated lumber diaphragms. All glue lines are made up of elastomeric adhesives having stiffnesses of 90 psi‐900 psi. The use of such adhesives provides an incomplete partial composite. Three parameters which influence the behavior of diaphragms are studies. These include the stiffness of glue lines, the number of courses, and properties of the decking. Analytical results show that a large number of layers produces flexible diaphragms. It is also shown that gluing a few of the courses along the outer edges of the diaphragm may be sufficient to provide the proper strength and serviceability. In addition, the use of higher grade wood for the outer layers provides economical means of obtaining the strength required.

Direction toward High Grade Wood and Demand Decrease of Domestic Wood (Trend of Timber Market)

Direction toward High Grade Wood and Demand Decrease of Domestic Wood (Trend of Timber Market)

Viscosity of 25% solutions of cellulose acetate versus intrinsic viscosity distribution

AbstractThe 25% w/w solutions of blends of cellulose acetate fractions have higher viscosities than solutions of single fractions of the same average intrinsic viscosity. It was found that the viscosity of a blend can be related to its composition by the relationship: where \documentclass{article}\pagestyle{empty}\begin{document}$[\bar \eta ]_{25\%}$\end{document} is the apparent intrinsic viscosity of the cellulose acetate blend in solution at 25% concentration, and [η]i are the intrinsic viscosities of the components. By application of this equation it was determined that only a portion of the high anomalous viscosity of solutions of cellulose acetate prepared from viscose grade wood pulp could be attributed to intrinsic viscosity distribution.