Nanosilane in medium-density fibreboard: effects of vapour chamber on fluid flow

Effects were studied of vapour chamber on specific gas permeability of nanosilane (NS)-treated medium-density fibreboards (MDFs). Size range of nanoparticles was 20-80 nm. NS was used at four consumption levels of 0, 50, 100 and 150 g/kg dry wood fibres. Density of all treatments was kept constant at 0.67 g/cm(3). Specimens were kept for 18 weeks in vapourised chamber; their specific gas permeability was measured every two weeks. Results showed that extreme moisture uptake because of the biological structure of wood fibres, as well as mold and fungi growth on the specimens from the tenth week, resulted in the breaking down of the urea-formaldehyde resin; they also weakened the water-repellant effect of NS; consequently, the permeability increased significantly. It can be concluded that NS makes MDF susceptible to molds and therefore NS-treated MDF panels are not recommended for moist climates in which boards are exposed to water vapours in the air for a long time, although NS-panels primarily showed higher impermeability to water.