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Se determinó la variación del contenido de humedad de equilibrio (CHE) en el tiempo, en especies con diferente densidad básica (Db). Además, se generó un modelo para la predicción del CHE en función de los factores ambientales y algunas propiedades físicas de la madera Probetas de 2.5 x 7.5 x 20 cm, en espesor, ancho y largo, respectivamente, provenientes de 3 coníferas y 6 latifoliadas, fueron ubicadas en un cobertizo al exterior, y se controló el peso (Pa) de ellas, así como también, la temperatura (T)y la humedad relativa(HR) del aire, una vez por semana y por dos años. Finalizado el ensayo, se determinó la densidad básica (Db), densidad anhidra (Da), peso específico de la pared celular anhidra (Gbpc) y la porosidad anhidra (V), de las probetas La variación del CHE de la madera en el tiempo, fue mayor en especies de menor Db y mayor V. El modelo que consideró la T, HR, Gbpc y Pa, como variables independientes, explicó en un 98,5% la variación del CHE. El coeficiente de correlación (R) entre valores del CHE medidos y del CHE estimados por el modelo, fue 0.979.The equilibrium moisture content (EMC) variation owing to the time in species with different basic density (BD) was determined. Further, of generating a model for the prediction of EMC as a function of environmental factors and some physical properties of wood Small samples of 2.5 x 7.5 x 20 cm in depth, width and length, respectively, from 3 conifers and 6 hardwoods were located in a shed at the exterior. And the weight of small samples (WSS), as well as, the temperature (T) and relative humidity (RH) of air were controlled, once a week and for 2 years. After finishing the trial the basic density (BD), oven dry density (ODD), specific gravity of the cell wall (SGCW) and porosity (P) of the small samples were determined EMC variation of wood in relation to the time was higher, in species with lower BD and higher V. The predicting model that considered the T, RH, SGCW and WSS as independent variables explained in a 98.5 % the variation of EMC. The correlation coefficient (R) between measured EMC and estimated EMC by the predicting model was 0.979.

Se determinó la variación del contenido de humedad de equilibrio (CHE) en el tiempo, en especies con diferente densidad básica (Db). Además, se generó un modelo para la predicción del CHE en función de los factores ambientales y algunas propiedades físicas de la madera. Probetas de 2.5 x 7.5 x 20 cm, en espesor, ancho y largo, respectivamente, provenientes de 3 coníferas y 6 latifoliadas, fueron ubicadas en un cobertizo al exterior, y se controló el peso (Pa) de ellas, así como también, la temperatura (T) y la humedad relativa(HR) del aire, una vez por semana y por dos años. Finalizado el ensayo, se determinó la densidad básica (Db), densidad anhidra (Da), peso específico de la pared celular anhidra (Gbpc) y la porosidad anhidra (V), de las probetas. La variación del CHE de la madera en el tiempo, fue mayor en especies de menor Db y mayor V. El modelo que consideró la T, HR, Gbpc y Pa, como variables independientes, explicó en un 98,5% la variación del CHE. El coeficiente de correlación (R) entre valores del CHE medidos y del CHE stimados por el modelo, fue 0.979. Abstract The equilibrium moisture content (EMC) variation owing to the time in species with different basic density (BD) was determined. Further, of generating a model for the prediction of EMC as a function of environmental factors and some physical properties of wood. Small samples of 2.5 x 7.5 x 20 cm in depth, width and length, respectively, from 3 conifers and 6 hardwoods were located in a shed at the exterior. And the weight of small samples (WSS), as well as, the temperature (T) and relative humidity (RH) of air were controlled, once a week and for 2 years. After finishing the trial the basic density (BD), oven dry density (ODD), specific gravity of the cell wall (SGCW) and porosity (P) of the small samples were determined. EMC variation of wood in relation to the time was higher, in species with lower BD and higher V. The predicting model that considered the T, RH, SGCW and WSS as independent variables explained in a 98.5 % the variation of EMC. The correlation coefficient (R) between measured EMC and estimated EMC by the predicting model was 0.979.

The purpose of this paper was to determine the mechano-sorptive strains produced during desorption of moisture from Eucalyptus nitens specimens, from a perspective of modeling wood drying stresses. Eucalyptus nitens samples were tested in the radial and tangential directions. The mechano-sorptive strain was measured by cantilever bending during desorption. The runs were performed in a conditioning chamber at constant low temperature and variable equilibrium moisture content. Four load levels were considered for testing. The results showed that the mechano-sorptive strain during desorption of moisture was proportional to applied stress and reached the maximum value in the tangential direction. Also, the mechano-sorption coefficient depended on wood orientation and reached the maximum value of 5.46 × 10-2 in the tangential direction.