Water absorption characteristics of three wood varieties

Abstract

Water absorption process during wood soaking in water was studied on three varieties of wood. Two models were considered to describe the kinetics: the Peleg model and a new one based on the viscoelastic properties of materials. The soaking data were fitted to the Fick’s model to determine water diffusivity. The pattern of water uptake suggested a two stepprocess, in which more than half of the final absorbed water occurred in the first two days of liquid water contact with wood. This was followed by a period of very slow water uptake. The mean values of water absorption at initial stages of moisture sorption for Afra, Ojamalesh and Roosi genotypes were equal to 13.44, 6.05 and 5.44 (kg/m2 s1/2), respectively. The corresponding mean values of this parameter for the entire soaking process were equal to 6.8, 4.6 and 3.9 (kg/m2 s1/2), respectively. The calculated diffusion coefficients for Afra, Ojamlesh, and Roosi wood varieties were 1.38x10-3, 3.71x10-4, and 4.88x10-4 m2/s, respectively. The newly introduced model was more accurate for describing the water absorption characteristics of wood samples. The maximum value of root-mean-square deviation was 9.36, which demonstrated the suitability of the new model for modelling the experimental absorption characteristics of wood samples.