INFLUENCE OF THERMAL MODIFICATION ON THE PHYSICAL AND MECHANICAL PROPERTIES OF Eucalyptus badjensis MIXED PARTICLEBOARD / OSB PANELS

Resumo

The objective of this research was to evaluate the effects of thermal modifications, at different temperatures and exposure times, on the technological properties of mixed particleboard / OSB panels made out of Eucalyptus badjensis. Using the wood of Eucalyptus badjensis, Particleboard, OSB and mixed Particleboard/OSB panels (control and thermally modified) were manufactured. The mixed panels’ thermal modification was carried out under three temperatures (180ºC, 200ºC and 220ºC) and two exposure times (10 minutes and 12 minutes). For the panels’ manufacturing, 6% of phenol-formaldehyde adhesive and 1% of paraffin were employed, which was calculated based on the particles’ dry mass. The water absorption and thickness swelling properties were evaluated after 2 and 24 hours of immersion, in addition to the panels’ modulus of elasticity, modulus of rupture and internal bond. Based on the results, we were able to conclude that the thermal modification affected most of the physical properties positively. From the different exposure times studied, the most effective one was the period of 12 minutes, especially for water absorption after 2 hours, which caused a reduction of 11.27%. In turn, the most effective temperature was of 220ºC, highlighting the thickness swelling after 24 hours, which caused a swelling decrease of 23.76% in comparison with the control panels. Regarding the mechanical properties, the thermal modification, in terms of the studied exposure times and temperatures, did not affect the results of the mixed particleboard /OSB panels.