Optical performance of finished and unfinished tropical timbers exposed to ultraviolet light in the field in Costa Rica
2018-07-17T18:24:44Z
Moya-Roque, R., Salas, C., & Vargas-Fonseca, L. (2016). Optical performance of finished and unfinished tropical timbers exposed to ultraviolet light in the field in Costa Rica, Wood Material Science & Engineering, 11(2), 62-78.
17480272
Artículo científico
This study evaluated wood color change (ΔE*) and the surface quality in 10 tropical wood species painted with three
finishes (composed of wax and polyurethane). Two weathering conditions were tested: natural weathering (NW) and
artificial weathering (AW). The results showed that the application of these finishes, decreased the luminosity (L*),
increased the redness (a*) and the yellowness (b*) parameters in all species. ΔE*, after weathering exposure, was affected
significantly by L*, a*, and b, whereas for finished or pretreated wood, L* and b* are the main parameters affecting ΔE* in
the 10 tropical species studied. ΔE* values found in different finishes and pretreatments are cataloged as total change of
color. Other important results were that tropical light colored timber with natural pretreatment produced higher ΔE* than
dark colored timber. The stains and fungal development were observed in polyurethane finishes in NW, but not in AW. The
irregular and mosaic flaws were not observed in any kind of finish or pretreatment of surface. The values of the quality index
created, which considered long and short lines and switch flaws, were lowest in NW and in waxy finish, while the highest
value was obtained with the polyurethane finish.
Instituto Tecnológico de Costa Rica
Lidia Gómez
Cartago - 300m Este del Estadio Fello Meza. Apartado 159-7050.
2550-2263, 2550-2365