Comparative Analysis of Wettability of Hybrid and Indigenous Poplar Strands

The increasing demand for sustainable raw materials in engineered wood production has prompted the evaluation of alternative raw materials. In this context, indigenous black poplar (Populus nigra) was analyzed as a potential alternative, by testing its wettability, characterized by contact angle, determined by the sessile drop method, to predict its adhesion when used as strands for OSB and LSL production. Surface tension was tested on strands with a wide range of surface roughnesses. The results show minor but statistically significant difference in favor of black poplar, which has somewhat lower contact angle values (62.01°) than hybrid poplar (64.71°), based on 300 measurements each. The absorption of the liquid into the strands, evaluated on a smaller sample, follows a logarithmic relation with time. These results also show a slightly faster decrease in contact angle in case of indigenous poplar, compared to hybrid poplar. The results indicate that the adhesion of indigenous poplar strands does not present extra challenges, compared to the currently more frequent hybrid poplar strands.