A method for reducing the amount of PCP in wood with less detriment to protection against fungi

Abstract

Large pieces of wood were immersed in a solution of pentachlorophenol (PCP) in order to introduce this chemical into the wood, the chemical being able to protect the wood against fungi. A method was explored to reduce the cost of the operation by decreasing the amount of PCP and the time of absorption. It consists of creating high gradients of concentration of PCP in the wood with a high concentration on the surface. In order to evaluate the level of protection by the PCP, it is desirable to know the profiles of concentration of this chemical developed through the wood. Experiments were performed either by immersing wood samples in solutions of the chemical over given periods of time or by measuring the amount of chemical introduced in the wood. An analytical solution able to describe the process of absorption, with the diffusion through the anisotropic solid, was used. As a result, the profiles of concentration of the chemical developed throughout the wood sample were obtained. The use of dimensionless numbers makes the results more general, whatever the size of the wood sample.