Effect of permeability on primary processing of wood

Abstract

Wood, being hygroscopic in nature, its permeability affects the flow of liquid and gases. Permeability defines the ease of flow of fluid due to a pressure gradient. Various methods like falling water displacement method, rota meter method, etc. have been employed in measuring the variable traits of permeability. In wood, it depends upon the effectiveness of interconnecting capillaries such as pit, pores which constrict the passage from one cell cavity to the other. The size of openings connecting the wood cells determines the degree of permeability. Permeability is a function of porosity which in turn is dependent on the wood species. It varies with respect to the type of wood species i.e. hardwood and soft wood as well as in different directions within the wood. It can be altered by ponding, steaming, heat treatments, chemical treatments etc. Permeability is an integral part in determining the longevity influencing many other processes viz., wood seasoning, preservatives treatment and pulping processes. Thus, its application in the field of wood science is justified.