Gochev, Zhivko The effect of the focal length position of the focusing lens on the discoloration roughness of plywood under different CO2 laser engraving modes / Zhivko Gochev, Pavlin Vitchev. -- Obr., tab. -- The results of a surface roughness study obtained by CO2 laser engraving of birch plywood specimens are presented in the paper. A ZnSe lens with focal length F = 50.8 mm; focal position ∆F = -4, -6, and -8 mm above the material surface; laser beam power P = 4.0, 5.6, and 7.2 W; laser beam scanning speed vf = 250, 260, and 270 mm/s was used for the research. The roughness of the treated surfaces was measured with an electronic profilometer, model Surftest SJ-210 (Mitutoyo – Japan). The experimental results were evaluated via the parameters Ra, Rq, and Rz and analyzed using specialized software Q-StatLab, ANOVA analysis, and interaction diagrams of all parameters, and relevant conclusions and recommendations were made. The analyses indicate that the surfaces of birch plywood treated with a CO2 laser exhibit higher roughness than untreated ones, with a deviation of 2 to 4 times greater for the Ra parameter and 2.2 to 3.9 times greater for the Rz parameter. The primary reason for the difference in surface roughness of CO2 laser-treated materials at different focusing positions on the surface is the varying laser beam power density. A higher beam power density leads to more significant absorbed heat, resulting in increased surface roughen.

In Acta Facultatis Xylologiae Zvolen : vedecký časopis Drevárskej fakulty. -- Zvolen : Technická univerzita vo Zvolene, 2024. -- ISSN 1336-3824. -- Vol. 66, no. 2 (2024), s. 75-87

I. Vitchev, Pavlin
II. Acta Facultatis Xylologiae Zvolen : vedecký časopis Drevárskej fakulty. -- Vol. 66, no. 2 (2024), s. 75-87

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