Influence of poplar wood densification on surface characteristics and adhesion strength

The main purpose of this study was to evaluate the effect of densification process on the surface characteristics and bonding quality of poplar wood. For this purpose, the specimens were treated by hygrothermal treatment and then were densified by hot press. Some properties of treated specimens such as surface contact angle and surface roughness were evaluated before and after planning. Moreover, the shear strength of glue line and also delamination of specimens in soaking-drying and boiling-drying cycles were investigated. The results of the poplar wood densification revealed that the surface roughness of the specimens reduced and surface contact angle increased by hygrothermal pre-treatment. The results also showed the positive effect of combined hygrothermal and compression treatment on the delamination after soaking-drying and boiling-drying cycles. In addition, the shear strength of glue line reduced by applied combined treatments. In addition, microscopic images showed that this process changed the physical structure of the surface.