How far does a gaseous reagent penetrate into wood

The reaction between wood components and vaporous formaldehyde was applied to the evaluation of gas permeability and forecast of the extent where the reaction occurs. The structural changes of pre-compression wood, which is a new method to suck the liquid reagent by the recovery force, was also followed by the established method. The formaldehyde content (y) reacted with wood components decreased exponentially as according as the depth from the penetrating surface. It could be expressed by the distance from surface, x, for both longitudinal and tangential directions as follows; y=kexp(-ax) where, a and k are constants for individual wood samples. The half-interval (a definite distance of half reduction), d(1/2), was defined by (In 2)/a. The reaction level at the arbitral inner portion of wood can be estimated by both the half-interval and the reaction level at the vicinity of surface region. The use of the structural changes of pre-compression wood is suggested.