Influence of heat treatments on the MOR and MOE of panels made from thin (dmax=160 mm) sessile oak (Quercus petraea spp. Matt. Liebl.) trees.

Sustainable forest management is meant to ensure forest goods and services purchased in response to immediate requirements and at the same time ensuring their continued availability and contribution to long-term development. On the 8 th of July 1999, the European Council Regulation regarding measures to promote the conservation and management of forests came into force and refers to the potential recovery of wood secondary resources approximated to 9-10%, which opens subjects of research for a better insight to this matter. The ecological benefit of using secondary wood resources can be further enhanced by heat treatment, which is an ecological modality to improve some properties, such as hygroscopicity, dimensional stability and durability, as a consequence of the changes which occur in the chemical composition of wood under the effect of high temperature. In this research a comparison was made between untreated solid longitudinally textured wood panels and heat treated ones, regarding density, mass, modulus of elasticity and bending strength. The objective of the study was to determine if heat treatment, besides its benefits, has any negative effect on the MOR and MOE of solid wood panels. The solid wood panels are made of timber cut from thin (dmax=160mm) sessile oak (Quercus petraea spp. Matt. Liebl.) trees, which resulted from thinning operations of forestry. Two types of joining were investigated: edge to edge joint and finger joint panels, both heat treated and untreated. Raw material was heat treated at 130 o C for 2h and the tests on panels were performed according to EN 310:1993. Heat treatment caused a drop of density (by 19kg/m 3 ) and mass (by 0.3-0,4kg/m 2 ) in both panel types compared to the untreated panels. The differences between the values of MOR and MOE for treated and untreated panels is insignificant (around 1,5%). This research confirmed the hypothesis that making panels out of thin sessile oak trees is feasible and rewarding. The results regarding MOE and MOR show that these panels can be used successfully in furniture production and the values, comparable with laminated densified wood, indicate an expansion of the utilisation field, if their dimensional stability offers good results.