WETTABILITY AND SURFACE ROUGHNESS OF NATURAL AND PLANTATION-GROWN NARROW-LEAVED ASH (Fraxinus angustifolia Vahl.) WOOD

Abstract

Plantation-grown wood species are becoming more important. Their anatomical, physical, and mechanical properties are different and generally more variable than wood grown in natural stands. The objective of this study was to investigate the wettability and surface roughness (SR) of natural and plantation-grown narrow-leaved ash (Fraxinus angustifolia Vahl.) wood. The logs were cut from a natural stand versus three different spacings of plantation-grown narrow-leaved ash wood stands. Plantation spacings were 3 x 2 m, 3 x 2.5 m, and 4 x 4 m. The wetting behavior of the wood samples was characterized by the contact angle (CA) method (goniometer technique). A stylus type profilometer was used for the SR measurement according to the DIN 4768 (1990) standard. The SR and CA measurements were done on both the radial and tangential surfaces of the samples. Individual values of both SR and CA of ash wood showed statistically significant differences. Based on the findings, it appears that the natural-grown ash wood have higher (less favorable) SR and lower (more favorable) CA values compared to all the plantation-grown ash wood on both radial and tangential surfaces. Tangential surfaces had lower SR values and higher CA values than the radial surfaces for all groups. In conclusion, plantation-grown narrow-leaved ash wood can be utilized for bonded wood products such as plywood, laminated veneer lumber, and glulam.