Improving impregnation and penetration properties of refractory woods through cryogenic treatment

Abstract

Cryogenic treatment via liquid nitrogen (LN) was evaluated as a means to improve the capability of impregnation and penetration in fir and spruce wood. There are a few vital problems that occur during the impregnation process of wood protection. One problem is that refractory woods have different anatomical features that make the impregnation process difficult. For the specimens that were conditioned with the air and oven, the retention changes were determined with an image analysis, scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDX). In addition, the density and equilibrium moisture content (EMC) values were measured. The LN treatment resulted in degradation in the bordered pits. Then, the margo and torus bonds were torn, the bordered pits were opened, and the liquid transportation of wood was facilitated. It was determined that the LN treatment and impregnation increased the depth and dispersion capability of the penetration. The LN treatment helped facilitate the flows from pores to pores by hindering the aspirations of the bordered pits, and thus the flow of chemicals was facilitated. Obtaining deeper penetration in refractory wood species will result in an improved impregnation process.