Infrared and colorimetric characterization of discolored kiln-dried hard maple lumber
2004
Dawson-Andoh, B.E. | Wiemann, M. | Matuana, L. | Baumgras, J.
Discoloration of hard maple lumber commonly occurs during kiln-drying. In this study, discolored and nondiscolored kiln-dried hard maple lumber boards were characterized using a colorimetric method and Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR). Colorimetric measurements (L*, a*, b*) were found to be in good agreement with visual grading. Brightness or lightness (L*) of hard maple lumber decreased with discoloration while redness (a*) and yellowness (b*) increased with discoloration. The pH and metal ion content of lumber appeared to play no role in the discoloration process. ATR-FTIR spectra of lumber revealed that although all lumber boards exhibited similar features in the fingerprint and other regions, there were differences in intensities of some absorption bands. One significant difference between accepted and rejected lumber boards was in the 1600-1717 cm(-1) region. ATR-FTIR alone was not sensitive enough to adequately describe changes in chemistry of discolored and discolored hard maple lumber boards.
显示更多 [+] 显示较少 [-]