WOOD RESEARCH Volume 69, Number 1, 2024
HARUNA SEIDU, MARWA BROUGUI, NOOR ROZIANA ABDUL RAHIM, and RÓBERT NÉMETH

EVALUATION OF DYNAMIC AND STATIC MODULI OF ELASTICITY OF HYBRID EUCALYPTUS WOOD FROM DIFFERENT LOCATIONS IN GHANA

This study explores the mechanical properties of hybrid eucalyptus wood, with a focus on dynamic and static moduli of elasticity (MOE), which is crucial for understanding the stiffness behaviour of wood. The research employs acoustic and static measurements on samples prepared from six trees sourced from Winneba and Amantia in Ghana. The results reveal significant variations in static and dynamic MOE, with higher static MOE observed in both Amantia and Winneba samples. However, Winneba and Amantia samples at the tree level were found to be insignificant statistically. The densities of the samples from the two locations, Winneba and Amantia, were found to be significantly different. Correlation studies revealed strong relationships between wood density and static MOE, as well as static and dynamic MOE, providing valuable insights into the comprehensive characterization of the eucalyptus globulus species grown in Ghana

WOOD RESEARCH Volume 67, Number 6, 2022
HONGHAI LIU, XIAOKAI ZHANG, and Jingwen Zhang

Study of dewatering characteristics of eucalyptus wood by supercritical CO2

Wood collapse is a major defect for their applications in solid wood production. Supercritical CO2 (ScCO2) dewatering can quickly remove water in wood and effectively reduce the capillary tension leading to collapse of wood structure. In this study, Eucalyptus exserta F.V. Muell wood was dewatered using ScCO2 at 35, 45, 55°C and 15, 20, 25 MPa, separately. The dewatering characteristics and wood deformation were statistically analyzed and compared after dewatering. The results show that the dewatering rate of ScCO2 is affected by moisture content (MC) of wood, showing the higher the MC, the faster the dewatering. It is also affected significantly by pressure, indicating increased dewatering rate with the pressure. The effect of temperature on dewatering rate is not apparent as the pressure is less than 25 MPa, but it becomes significant at 25 MPa condition, showing an increased dewatering rate with temperature. In this experiment, the greatest dewatering rate was 19.8%·h-1 at 55°C and 25 MPa. The transversal shrinkage of all specimens after 5 cycles dewatering was lower than 1.5%, indicating the ScCO2 dewatering could effectively inhibit collapse of eucalyptus wood structure. The transversal shrinkage decreases with the pressure, and is not affected significantly by temperature.