Effect of the densification process on properties of commercial oriented strand boards

The objective of this work was to evaluate the effects of the densification on the physical and mechanical properties of OSB panels. A single-opening hot-press was used to perform the densification process. Four treatments were applied to densify the boards combining two temperatures (170 and 190 °C) and two pressures (25 and 50% of the compression strength perpendicular to the board plane). The properties of densified and undensified boards were assessed and the effect of temperature and pressure of the densification process was studied. It was found that undensified boards presented lower thickness swelling but higher water absorption and equilibrium moisture content than densified boards. Densified boards presented higher values of bending properties, parallel compression strength and hardness than undensified ones. The comparison within densified boards showed that in general the temperature was the most influential variable to modify the physical properties, while the mechanical properties were more affected by the pressure used. It can be concluded that the proposed densification process promoted remarkable changes on the OSB boards mainly regarding mechanical properties and water absorption. However, the thickness swelling remained as issue to be specially addressed in future works.