WOOD RESEARCH Volume 62, Number 6, 2017
Song Xiaozhou, Zhu Lingyan, Wu Shiqian, and Lei Yafang

Structural and mechanical properties of cork cell walls from quercus variabilis blume (Fagaceae)

The properties of cork are strongly dependent on its cell wall properties. Thus, it is very important to characterize the cork cell walls in order to understand structure-property relationships. The reproduction cork tissue from Quercus variabilis Blume was examined with field-emission scanning electron microscopy to detect the structural characteristics of the cell walls. Several noteworthy anatomical features were present in the cells of Quercus variabilis cork. In most instances, the inner wall of cork cells was not smooth and showed an irregular surface. Solid deposits of various shapes were observed in the inner surfaces of the cell walls. Cell walls of cork tissue had severe corrugations in transverse and radial sections. Trabeculae were found for the first time in the cork tissue of Quercus variabilis Blume. They extended across a few cells, with a rod-like form. Nanoindentation techniques provide a new view of the mechanical properties of the cork cell walls. The hardness of cell walls of untreated and boiled reproduction cork from Quercus variabilis was 0.54 GPa and 0.51 GPa. The elastic modulus was 11.47 GPa and 11.81 GPa, respectively. Boiling treatment of cork could improve mechanical properties of cell walls.

WOOD RESEARCH Volume 65, Number 3, 2020
Ruyuan Yang, Xiaofeng Zhang, Youfu Sun, Tingting Zhou, and Quan Yuan

Effect of the metallization treatment on the surface properties of Populus euphratica

To improve the surface-finishing performance and enhance the protection of surface coatings, this study employed metallization treatment of fast-growing poplar through an orthogonal experiment. The poplar specimens were impregnated using a low-melting point alloy at different temperatures (75°C, 85°C, 95°C), pressures (0.5MPa, 1 MPa, 1.5 MPa), and times (0.5h, 1h, 2h) to obtain the optimum process parameters and determine the paint film adhesion of metalized poplar. The test results showed that the impregnation effect was obvious with an increase in the pressure and time. The optimum process parameters were 0.5 MPa, 85°C, and 1 h. Contact angle of the treated wood increased, the surface free energy dropped to some extent, wetting property of tread wood decreased. Whether the treated wood or the untreated wood, film adhesion of treated wood got a higher level. After anti-aging treatment, the treated poplar still had a higher level of film adhesion.

WOOD RESEARCH Volume 64, Number 1, 2019
Tungalag Ayush, Ayursed Jigjjav, Bayartsetseg Baasan, Yus Andhini Bhekti Pertiwi, Futoshi Ishiguri, and Shinso Yokota

Drying performance of a direct-fired kiln developed in Mongolia

Smoke drying by means of a direct-fired kiln is considered to be one of the most cost-effective methods of drying lumber. In the present study, Siberian larch (Larix sibirica) lumber was dried using a direct-fired kiln developed in Mongolia. When approximately 500 kg of sawdust was used as fuel, the maximum and mean temperatures in the kiln were 78.2°C and 54.2°C for the lower side, respectively, while they were 70.4°C and 50.1°C for the upper side, respectively. The temperature inside the kiln was above 60°C for a duration of about 40 to 50 hours. The moisture content of the lumber decreased from 56.4% to 23.2%. No significant differences in terms of the mechanical properties were found between air- and smoke-dried wood. Based on these results it appears that the direct-fired kiln developed in Mongolia is useful for the low-cost drying of Siberian larch lumber, although improvements to the kiln and a prolonged drying schedule are needed in order to obtain more dried lumber.