Mahogany Wood Surface Properties

This paper analyzed the wood surface color, luster and roughness of 19 different species of HONGMU in 8 groups. According to these data, the distribution characteristic of its visual physical magnitude, general rule of its light and heat discolorations were discussed. Besides, this paper also discussed the distribution characteristic of its roughness and the relationship between the roughness and microcosmic structure. The results are as follows:(1) The variation ranges of parameters L^*, a^*, b^*,V, C and H were 26～47,1～17,1～21,1～4,1～13,9R～4Y respectively. Most of these are in YR color and in low lightness.(2) With Ward cluster analysis, it showed that red sandalwood, ebony, strip ebony, black rosewood and Jichi were in the first class, while padauk, scented rosewood and red rosewood were in the second class. Euclidean distance between this two clusters was 30.80.(3) All indexes of HONGMU surface color parameters are not different among species in the same genus, while discrepancy is notable among different genus, that proved the exactness of HONGMU classification from the point of view of chroma.(4) The distribution range of GZL, GZT and GZB were 5.77%～15.02%, 4.07%～7.7%, 1.23%～2.42% respectively. The surface luster and GZB of no painted rosewood were higher than that of common wood.(5) The light discoloration from graveness to minuteness that can be identified were red sandalwood, padauk, red rosewood and black rosewood; while the light discoloration can not be identified were scented rosewood, ebony, strip ebony and Jichi, among which the light discoloration of ebony is in the least.(6) The result of FTIR of HONGMU which were radiated by the ultraviolet light showed that: the wood that have graver light discoloration have more inclusion, so it showed more absorbed peak. the wood surface color that changed a little have no evidence absorbed strip in 1730 cm^-1, and the change of absorbency in 1600,1510,1270 cm^-1 are little, vice versa.(7) The indexes of L^*,a^*, b^*, c^*, ΔE^* are changed with the time being in heating process, and the variation extent is lager as the heating temperature increased. Red sandalwood has the most evident heat discoloration, and the heat discoloration of black rosewood also can be identified due to the intensitive heat discoloration of Dalbergia louvelii. The heat discoloration of other 6 genus can not be identified, among which the heat discoloration of ebony is in the least. The variation extent of heat discoloration is minuter than light discoloration.(8) The discoloration of Dalbergia louvelii is different from black rosewood, while it is the same as red sandalwood and padauk.(9) The multinomial wood surface roughness indexes of HONGMU from small to large were: scented rosewood, strip ebony, ebony, red sandalwood, black rosewood, red rosewood, padauk and Jichi, which is coincident with the HONGMU standard.