THE EFFECTS OF TEMPERATURE AND BAKE-OUT ON FORMALDEHYDE EMISSION FROM WOOD COMPOSITES OF UREA-FORMALDEHYDE RESIN

摘要

This paper describes the effects of temperature on formaldehyde emission from wood composites using the desiccator test and the results from the bake-out of wood composites. Two specific types of composites were studied: particleboard (PB), medium density fiberboard (MDF). Formaldehyde emission levels from wood composites could be expected to increase with increasing temperature. The rate of increased formaldehyde emission levels was not constant, but showed strong temperature dependence. On average, the formaldehyde emission level was increased three-fold with a 15°C increase in temperature from 20°C to 35°C. The composites were baked out for 1, 3, 5, 7, 10, 14, 21, and 28 days at temperatures of 20±2, 35±2, and 50±2 °C in a dry oven. The bake-out procedure demonstrated worthwhile potential to reduce formaldehyde concentrations in new or renovated buildings. Longer bake-out times may be necessary to achieve the desired reductions in formaldehyde concentrations. The largest decreases in formaldehyde concentrations occurred at least one week after the bake-out time.