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 A REVIEW OF THE LITERATURE AND SOME UNPUBLISHED WORK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 varia ble determining the outcome of hot pressing, and the success of post t reatments for composite products. The existing literature on the perme ability of reconstituted wood products is reviewed. The effect of prod uct density on permeability is great; unfortunately, most materials te sted to date have contained a systematic spatial variation of density. As a result, the true density vs. permeability relationship remains u ncertain. This uncertainty clouds the data on the effect of other vari ables (particle geometry, etc.) on board permeability. There is a need to reexamine the density vs. permeability relationship in materials n ot exhibiting internal density variation.