ABSTRACT
Several commercial timber species, although producing
very useful and attractive products, present the timber
industry with significant drying, durability, stability,
machining, and treatment problems. These species gener-
ally have low permeability and are particularly difficult to
dry quickly without degradation. Distortions because of
collapse, twist, bow, and cupping, in conjunction with
surface and internal cracking, significantly reduce com-
mercial recovery rates for many species. Similarly, many
species exhibit poor preservative uptake. Many of these
problems are directly linked to wood permeability and
density. Permeability and density are inherent properties
of the raw material and are difficult to manipulate using
conventional technology.
