Study on machining properties and surface coating properties of heat treated densified poplar wood

In this study, a modification combining densification and heat treatment of poplar wood (Populus tomentosa Carr.) was carried out, and the machining properties of the unmodified poplar wood (control) and the heat treated densified wood (HTD) were tested and evaluated. In addition, the water-based UV paint was covered on the control and HTD respectively, and the surface coating properties of them were evaluated. The results showed that: (1) The machining properties of poplar wood were improved after the heat treatmentdensification modification. The score of comprehensive machining properties of the HTD was 45 (excellent grade), while the score of the control was 36 (good grade). (2) The abrasion resistance, hydrophobicity and adhesion were improved after heat treatment-densification modification. Therefore, the modification combining densification and heat treatment played a significant role in enhancing the value of wood.

Effect of heat treatment on bamboo fiber morphology crystallinity and mechanical properties

This study aimed to investigate the fiber morphology, crystalline structure and mechanical properties of heat-treated bamboo. Moso bamboo was treated by superheated steam at 120, 140, 160, and 180ºC. Fiber morphology and crystalline structure of heat-treated Moso bamboo were researched by transmission electron microscope and X-ray diffraction. The mechanical properties of heat-treated bamboo were tested in the paper. The result showed that the relative crystallinity and length-width ratio of heat-treated bamboo were increased with increased temperature. The elastic modulus of bamboo was increased as the temperature rose from 120 to 140ºC. and then decreased with higher temperature, which was associated with the increase of the crystallinity.