Effect of CO₂ Laser Processing Parameters and Grain Direction on Color Change and Surface Roughness of Pine and Beech Wood

Abstract

This study was conducted to determine the effects of CO₂ laser scanning speed, laser processing power, and fiber direction on color change and surface roughness in Scots pine (Pinus sylvestris L.) and Eastern beech (Fagus orientalis Lipsky) wood. To this end, laser processing was performed at four scanning speeds (200, 300, 400, and 500 mm/s) and five power levels (12%, 13%, 14%, 15%, and 16%) in both parallel and perpendicular directions to the grain. The surface roughness and total color changes observed in the samples were determined in accordance with TS EN ISO 21920-2 and ASTM D2244-25 standards. As a result, while Scots pine samples exhibited higher roughness values than Eastern beech, the total color change was higher in Eastern beech samples. A low scanning speed and high laser power increased both roughness and color change. Processing parallel to the grain increased roughness, while processing perpendicular to the grain resulted in a higher color change.