EFFECTS OF RESIN AND WAX ON THE WATER UPTAKE BEHAVIOR OF WOOD STRANDS

Dimensional stability is an important property of wood composites. Both resin and wax are essential additives in the manufacture of composite panels such as OSB. Resin binds wood elements together while wax acts as a water repellent. The objective of this study was to investigate the effects of phenolformaldehyde resin and emulsion wax on the water uptake behaviors of commercial southern yellow pine strands using a wicking test. During the test, the water uptake amounts of strands blended with different resin and wax levels were recorded continuously. The effects of different factors on water uptake behaviors of strands were analyzed with ANOVA. The results indicated that resin level, wax content, grain direction, and strand density had significant effects on water uptake behaviors of strands. Lower resin level and wax content led to a rapider water uptake rate during the early stage of the wicking test and a larger total amount of water absorbed at the end of test. Water uptake behavior along parallel-to-grain direction differed from that perpendicular-to-grain direction, and strands with higher density tended to have relatively lower total water uptake amount.