Overlaying properties of fiberboard manufactured from bamboo and rice straw

In this study, surface characteristics of overlaid medium density fiberboard (MDF) panels manufactured from bamboo (Dendrocalamus asper) and rice straw (Oryza sativa) were evaluated. Experimental panels were manufactured from two types of raw materials. Samples with dimensions of 15 cm × 15 cm both types of panels were overlaid with decorative paper with a density of 0.75 g/cm3 using urea formaldehyde resin as a binder. Roughness measurements were randomly taken from the surface of overlaid samples using a fine stylus profilometer. Three roughness parameters, average roughness (Ra), mean peak-to-valley height (Rz), and maximum roughness (Rmax) were used to evaluate surface characteristics of overlaid samples conditioned at 55% and 92% relative humidity levels. Statistical analysis revealed that no significant difference was found between roughness values of panels made from two types of raw materials. When the samples were exposed to 92% relative humidity both types of specimens had significantly higher values of Ra, Rz, and Rmax than those of measurements taken at 55% relative humidity. The stylus method is able to detect differences in surface roughness of overlaid panels that can occur due to changes in environmental conditions. Initial findings of this study suggest that both non-wood under-utilized species can be considered as raw material to manufacture value-added MDF panels as substrate for overlaying without having any adverse influence on their surface quality.