Physical and mechanical properties of the stem and branch wood of West African ebony (Diospyros mespiliformis)

Abstract

This study examines the physical and mechanical properties of the sapwood and heartwood of the stem and branch wood of the West African ebony (Diospyros mespiliformis) to determine if the branch wood can be used for various products. Three mature Diospyros mespiliformis trees with stem diameters at breast height ranging from 50 to 65cm and branch diameters from 25 to 40 cm were purposively selected and felled. Wood samples were prepared to the exact sizes in accordance to the chosen standards, tested, and analysed. The results showed that wood density was insignificantly higher in the stem wood (551 kg/m³) than the branch wood (513 kg/m³). Radially, the heartwood had higher density than the sapwood for both stem wood and branch wood. The Modulus of Elasticity (MOE) was higher in the branch part (7066 MPa) than stem part (1903 MPa), and the sapwood recorded higher MOE for both stem wood and branch wood. Moreover, the Modulus of Rupture (MOR) had a similar result, with the stem part showing a higher average MOR (61 MPa) than the branch part (52 MPa), the sapwood had higher values as compared to its corresponding heartwood. The same trend was observed for the compression strength as well as Janka hardness. In general, it was shown that the branch wood could equally perform well when used as a supplement to the stem wood.

Keywords

• Diospyros mespiliformis, branchwood, density, ebony, heartwood, sapwood, stem