Measurements of colour development in pinus radiata sapwood boards during drying at various schedules
No hay miniatura disponible
Fecha
Autores
Título de la revista
ISSN de la revista
Título del volumen
Editor
Universidad del Bío Bío
Resumen
Descripción
Colour changes, such as kiln brown stain, that develop in Pinus radiata boards during kiln dryingcan reduce the value of the final wood products and result in significant losses due to downgrade orwaste of dried wood by removing the darkened surfaces. This study measured how colour developedin Pinus radiata sapwood boards under different drying schedules.The boards used in these experiments were 40x100x800mm, cut from the same log and were endandedge-matched. Boards were dried at eight different schedules using temperatures from 50°C to120°C and relative humidities from 14% to 67%. Separate boards were dried for 5 equal intervalsthrough each schedule and colour profiles measured through the boards using a surface reflectancespectrophotometer. Lightness, L*, on a greyscale was used as an indication of colour change (darkening).The results show that there is generally a greater decrease in lightness with higher temperatureschedules and also with slower, higher relative humidity, schedules. This suggests that both temperatureand drying time are significant factors in the formation of colour during drying. The most significantchanges in colour occurred near the board surfaces, indicating kiln brown stain.
Palabras clave
Agrociencias