Cork oak wood properties

• Autores: Sofia Leal, Vicelina Sousa, Sofia Knapic, Jorge Gominho, Hélène Callot, Helena Pereira, José S. Machado, José-Luís Louzada
• Localización: Suberwood: new challenges for the integration of cork oak forests and products / Javier Vázquez Piqué (ed. lit.), Helena Pereira (ed. lit.), María Arantzazu González Pérez (ed. lit.), 2008, ISBN 978-84-96826-47-2, págs. 393-402
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • With the objective of assessing the wood technological quality of cork oak (Quercus suber L.), several wood properties have been investigated, within the Suberwood European project, by the different research teams involved and with the contribution of external partners. A characterisation of cork oak wood is made here, summarising the main results achieved. The aesthetic quality of cork oak wood surfaces is dominated by the presence of large multi-seriate rays (in tangential sections with an average 5,2 mm in height and 0.5 mm in width) and of vessels with a semi-ring porosity (representing 4-9% of the area in the transverse section). In relation to its hygroscopic properties and dimensional stability, cork oak wood showed a medium fiber saturation point (25-32%) and higroscopicity (0.003) and was classified as a medium retractile wood (13-16% total volumetric retraction), with a medium to low linear retraction (tangential 7.5%-9.9%, axial 0.7%-1.6%, radial 3.5%-4.3%). The wood density determined by microdentsitometry showed an overall between ring and within ring homogeneity at an average ring density of 0,894, with a tendency to some radial decrease from pith to bark. Conventional wood density determinations at 12% moisture content varied from 0.63-0.67 g/cm3. The chemical analysis of the wood revealed a low ash content (1.5% on average), high extractives (12.7%), and an average lignin content of 25.4% (22.1% klason lignin). According to strength tests under axial compression, transversal tension and static bending, cork oak wood has medium mechanical strength. The wood natural durability was tested against two wood-destroying basidiomycete fungi (Coniophora puteana and Coriolous versicolor), and heartwood was rated as not durable and sapwood as slightly durable.