Effect of the temperature and pressure on properties of densified medium density fiberboards
The objective of this work was to evaluate the physical and mechanical properties of thermally compressed MDF (medium density fiberboard). For this purpose, MDF boards were subjected a combination of two temperatures (150°C and 170°C) and two pressures (25% and 50% of the perpendicular compression strength). After the treatment the following properties were assessed: bending strength and stiffness, compressive parallel strength, surface hardness, thickness swelling and water absorption after 2, 24 and 72 hours of immersion in water. It was found that in general, the results did not show any significant improvements regarding physical properties. However, mechanical properties were positively affected by treatments and densified boards had higher values than untreated boards, reaching a fourfold value in the case of the surface hardness. Regarding physical properties, there were no improvements compared to the untreated board for the thickness swelling, despite all treatments have showed lower water absorption. In general, temperature was the most important factor for physical properties and the pressure was the most important factor for mechanical properties.