Mechanical behavior and springback of acetylated particleboard made in different press times

In this study, the effects of acetylation and press time on the heat transfer from the surface to the core on the particleboard mat, springback, internal bonding, modulus of elasticity, and modulus of rupture were determined. Particles were soaked in the acetic anhydride for 24 h and heated in an oven at 120°C for 40 minutes, 3 h and 6 h to achieve three weight gain levels of 8%, 12%, and 17%, respectively. Acetylated and control boards were produced with 10% melamine urea formaldehyde (regarding the particles dry weight) and pressed for 5, 6, and 7 minutes. During the pressing process, the heat transfer to the core layer of the mat was measured by thermocouple made of Cr-Ni wires. It was found that the increase of acetylation level leads to significant reduction in heat transfer during manufacture process and develops springback which in turn, results in density loss. Findings indicated that these defects were correlated with the press time and compensated by the press time prolongation. Strength loss of the acetylated boards was due to debonding of the constituent that compensated somewhat with increasing press time.