Wettability of wood and adhesion

Adhesion theory is approached from the standpoint of surface energetics. Differentiation is made between smooth liquid surfaces and rough solid surfaces and a roughness factor r is introduced. The distinct wetting phenomena of adhesion, penetration and spreading are defined. Work Equations relating to these three wetting processes and a spreading coefficient are derived. Conditions to obtain effective wetting are described. Modification of wooden contact surfaces of aimed at improving surface energy is briefly discussed.