THE PERMEABILITY OF WOOD-BASED COMPOSITE-MATERIALS .1. A REVIEW OF THE LITERATURE AND SOME UNPUBLISHED WORK

The permeability of wood-based composite materials is a dominant variable determining the outcome of hot pressing, and the success of post treatments for composite products. The existing literature on the permeability of reconstituted wood products is reviewed. The effect of product density on permeability is great; unfortunately, most materials tested to date have contained a systematic spatial variation of density. As a result, the true density vs. permeability relationship remains uncertain. This uncertainty clouds the data on the effect of other variables (particle geometry, etc.) on board permeability. There is a need to reexamine the density vs. permeability relationship in materials not exhibiting internal density variation.