Effect of Density, Moisture Content, and Feed Speed on the Surface Quality of Planed Pinewood Boards

Abstract

The main goal of this study was to verify the best combination of density, moisture content, and feed speed on the surface quality of Pinus elliottii boards aimed at deck manufacturing. The secondary goal was to compare three methods of surface quality assessment. Tangential boards were sampled and sorted by density (level 1: 414 kg·m^-³ to 525 kg·m^-³; level 2: 526 kg·m^-³ to 668 kg·m^-³) and moisture content (level 1: 13.5% to 17.5%; level 2: 17.6% to 20.0%). A four-side planer molder was used, at three levels of feed speed (15, 20, and 25 m·min^-1). Surface quality was assessed immediately after machining by visual-tactile analysis, stylus surface profilometer reading (parameters R_a, R_z, and R_t), and feed per tooth (f_z) measurement. The best surface quality results were obtained with denser (526 kg·m^-³ to 668 kg·m^-³) and wetter boards (17.6% to 20.0% moisture content) at feed speed 20 m•min^-1. This recommendation represents an optimal balance between the quality standard of the deck boards and high productivity. Because of the low cost and because it has some correspondence with the stylus surface profilometer readings, visual-tactile analysis is recommended to assess the surface quality.