Review of the effects of incising on treatability and strength of wood
Jerrold E. Winandy, Babar Hassan, Jeffrey J. Morrell
Abstract
In wood, longitudinal fluid flow is several orders of magnitude greater than in radial or tangential directions. Incising of difficult-to-treat (i.e. refractory) wood species is a critical step in achieving adequate preservative penetration. Incising, as broadly defined, involves creating holes, incisions or fluid pathways to varying depths into the timber to increase longitudinal fluid flow and penetration into the wood. Incising has been used globally with early development occurring in the U.S., Canada, U.K. and Germany. It has been most heavily adopted in North America where it is required for treatment of thin sapwood lumber species in both the Canadian and U.S. treatment and engineering design standards. Incising can be either physical or biological. Physical incising uses teeth, knives, drills, needles, lasers, or high-pressure water jets to create pathways in the wood to the depth of the desired preservative treatment in a pattern that ensures uniform treatment. Biological incising uses bacteria or fungi to increase permeability. This review outlines the development, processes, applications and effects of incising technology. It specifically discusses their effects on treatability and strength properties, and reviews recent developments for modeling incising-related strength effects.