As the bordered pits have generally been thought to have an influence on the refractory nature of softwoods, structural behaviour of this conducting pathways is discussed according to the published literature. Various theories on the role of bordered pits to axial flow are expounded in respect to preservative treatment. Pit aspiration is also reviewed.

Despite evidence that lignin associates under both aqueous and organic media, the magnitude and nature of the underlying driving forces are still a matter of discussion. The present paper addresses this issue by examining both solution properties and size exclusion behaviour of lignins isolated from five different species of softwoods, as well as from the angiosperms Eucalyptus globulus and whe...

A brief overview of the structure of mannans in plant cell walls and other organisms is presented. In particular, mannans, galactomannans and glucomannans in seed endosperm and vegetative tissues such as bulbs and tubers, galactoglucomannans (GGMs) in primary cell walls, and glucomannans and GGMs in secondary walls of hardwoods and softwoods are covered. Possible roles of mannans in primary pla...

Five exploratory drying runs were carried out in a commercial size (23 m3), radio frequency/vacuum hardwood kiln. The species investigated were Pacific coast hemlock, Douglas-fir and western red cedar of different sizes and grades. Evaluation of the dried lumber showed that the three species can be dried in very short times and low amount of degrade irrespective of thickness with the exception ...

Fiber development in pulp refining can be characterized by three parameters: number of impacts on pulp, N; energy per impact, I, and bar force fibers, F. These parameters enable comparisons radically different conditions; determination intensity for hardwoods softwoods; assessment effect width fiber shortening; predictions tensile strength increases.