Sleeping beauties in materials science: Unlocking the value of xylarium specimens in the search for timbers of the future

Abstract

Wood ranks among the most valued resources in construction, for joinery and furniture. Rather than increasing the pressure on a limited number of species, we need to move towards a fit for purpose approach where the basis for selection of a material is a solid knowledge of its relevant properties. Therefore, knowledge about wood technological characteristics of a vast range of wood species is needed. Here, we exploit the potential of xylarium samples by mapping wood density and dimensional stability, using digital image correlation (DIC) on non-standardised samples, of 53 different tropical wood species from the Congo Basin. Furthermore, we attempt to link the results with quantitative anatomical features of the different species tested. DIC proved successful compared to standard calliper measurements on reference samples (R2-radial = 0.94, R2-tangential = 0.96). Vessel properties play a larger role towards explaining dimensional stability compared to wood density. Fibre wall thickness is positively related to wood density and volumetric swelling. We are able to differentiate between species and sample groups with similar behaviour, partially explained by their anatomical structure. Selecting species based on the required properties for the targeted end use as such can unlock the potential of currently unknown species.