COLOR CHANGES INDUCED BY CO2 LASER IRRADIATION OF WOOD SURFACE

The influence of color changes of wood surface with irradiation dose was examined in this work. Surface of two species - maple (Acer pseudoplatanus, L.) and beech (Fagus sylvatica, L.) was irradiated by CO2 laser beam. The color changes were measured by spectrophotometer. Results are calculated and depicted in CIE L*a*b* color system. With increasing irradiation dose from 14 to 57 Jcm(-2) we observed uniform growth of Delta E* for both wood species, from 2,5 to 57 (maple) and from 2 to 48 (beech). Values Delta a* a Delta b* of maple at first increased until maximum 7,2. Finally decreasing was (Delta a* to -0,6 and Delta b* to -12,7) occurred. Values Delta a* of beech decreased slightly to -5,7 and Delta b* to -15,5.