Water flow in different directions in Corymbia citriodora wood

Abstract

This study aims to evaluate the free and bound water flows in the different axes of Corymbia citriodora wood during drying. Wood samples were taken from the inner and outer regions of the tree stem from seven-years-old experimental plantations. The blocks were prepared for the water flow to occur in each wood axis and they were dried up to the final moisture content of 12%. Free water (FWFR), bound water (BWFR) and total water (TWFR) flow rates were calculated. The relationship between loss of moisture content and time presented an exponential curve, especially in the radial and tangential wood axes. Water flow in the three wood directions presented higher FWFR than TWFR (which was higher than BWFR). Free water flow was ~10 times higher than adsorbed water flow, considering values for moisture content between ~80% to ~12%. Free water movement in the longitudinal direction of the wood was ~2 times greater than in the radial axis and ~3 times greater than in the tangential axis. Bound water movement in the longitudinal direction of the wood was ~2 times greater than in the transverse direction. Bound water flow in the radial axis of the wood was statistically equal to the one in the tangential axis. The results indicate that the intensity of free and bound water flows changes according to the direction of Corymbia citriodora wood.