WOOD RESEARCH Volume 69, Number 3, 2024
CHENYANG LI, YATING CAI, XINJIE ZHOU, RUOGU XU, HAN YU, LILI YU, HUI LI, XIAO WANG, and SHU-GUANG LI

PREPARATION PROCESS AND INTERFACE MODIFICATION ON THE MECHANICAL PROPERTIES OF BAMBOO FIBER/POLYPROPYLENE CARBONATE COMPOSITES

In this study, bamboo fiber (BF) and polypropylene carbonate (PPC) were used to prepare BF/PPC composite materials. The single factor test combined with orthogonal experiment was used to investigate the effects of different hot pressing process conditions (hot pressing temperature, hot pressing pressure and hot pressing time) on the mechanical properties of BF/PPC composites. Based on the hot pressing process results, the filler nano-calcium carbonate (Nano-CaCO3), γ-aminopropyl triethoxysilane (KH550) and maleic anhydride (MAH) were added respectively to the composites to improve the interface between BF and PPC in order to increase the mechanical properties of the composites. The results showed that the reasonable preparation conditions of BF/PPC composites with the best mechanical properties were set at 170°C, under 1.9 MPa for 10 min. Compared with PPC samples, the tensile modulus, bending modulus and impact strength of BF/PPC composites could be increased to 102%, 38.69% and 65.13%, respectively. The optimal interface modification treatments have been proved that nano-CaCO3 with 10% content could increase the tensile modulus and impact strength to 70.53% and 65.84%, while the best result for the bending modulus of BF/PPC composites was modified with MAH with 2.5% content, which could increase to 28.46%

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.