Surface Properties of Pine Scrimber Panels with Varying Density

Abstract

Coating quality for scrimber products against exterior conditions is largely dependent on the surface properties. The wettability, morphology, and chemical composition of pine scrimber surfaces were investigated to better understand the surface properties. The scrimber was found to be a hydrophilic material because the water contact angles were less than 90°. The panels with a density of 1.20 g/cm3 had the largest angle change rate (k = 0.212). As the panel density increased, the instantaneous contact angle of each test liquid (i.e., water, formamide, and diiodomethane) on the panels decreased, and so did surface free energy. Panels with higher density showed lower surface roughness. Surface roughness across the wood grain was greater than that along the grain. SEM observations showed the high-density panels had a smoother surface with fewer irregular grooves in comparison with the low-density panels. X-ray photoelectron spectroscopy (XPS) analysis indicated that more unoxygenated groups appeared on the surface of high-density panels.

Effect of Resin Content on the Surface Wettability of Engineering Bamboo Scrimbers

“…Roughness depends on the material properties (e.g., density and porosity) and surface machining (e.g., sawing, planning, and sanding) [29,30]. Previous studies have found that high-density woody composites had low surface wettability and there is a strong correlation between the density and wettability [31,32]. Bamboo scrimber is a high-density composite composed of bamboo and phenolic resin, in which there are complex physical and chemical interactions between the two components.…”