Title : The worth of tropical hardwood branchwood as supplementary material to its stemwood for wood products manufacturing
Materials play vital roles in human existence, and wood is one of such materials on accounts of its application in areas such as housing, furniture, construction, paper making etc. The trees from which wood is obtained also perform unique duty to sustain lives of other living things on account of absorbing and storing CO2, and releasing O2 to keep a good balance in the atmosphere. Wood, especially tropical wood should therefore be used judiciously for forest conservation. We assessed branchwood as a readily available supplementary material to stemwood by comparing site and wood type influence on density, MOE, MOR, and compressive strength, all of which are important properties needed to ascertain the structural performance of materials, and using Entandrophragma angolense. Samples were obtained from two natural forest reserves and tested at 10 ± 3 %MC using ISO 3131-1975 and BS 373-1957 protocols. Results were that, though branchwood had significantly (p < 0.05) higher density, MOE, MOR and compressive strength were equivalent to those of stemwood, and site had non-significant influence on them. Density significantly (p < 0.05) influenced either MOE or MOR but not compressive strength. It was concluded that the responses of branchwood of E. angolense in terms of mechanical performance is very positive that they are as good as their stemwood counterparts. It is therefore recommended that the branchwood of E. angolense is a potential supplement to stemwood for wood products manufacturing. However, further studies on natural durability, finishing characteristics, shear strength etc. will be needed to enrich this positive response of branchwood as supplementary material to stemwood.
Keywords: Alternative materials, wood mechanical performance; Branchwood; Entandrophragma angolense; Site, Density, Human lives.
It is expected that audience will learn that:
1. The density of tropical hardwood branchwood, unlike softwood is higher than that of stemwood and has influence on the mechanical properties (bending MOE and MOR) and compressive strength//grain.
2. Forest site had no significant influence on the density, bending MOE, MOR, and compressive strength//grain in stemwood as in branchwood of E. angolense.
3. Mechanical properties of branchwood and stemwood are equivalent for E. angolense and therefore the two wood types can be used either separately or in mix for wood products manufacturing, especially where those properties are the priority.
4. Branchwood of E. angolense is as good as its stemwood, and therefore wood users such as those in building and construction, furniture making, car body works etc. should consider utilizing branchwood to reduce the pressure on stemwood extraction in order to conserve the forest.