Formaldehyde Release From Urea-Formaldehyde Bonded Wood Products

During the past decade significant progress has been made in reducing formaldehyde release from UF-bonded wood products. The purpose of this work was to test formaldehyde release from medium density fibreboard (MDF) manufactured in a commercial pilot plant using seven different UF resins with molar ratios between 1.85 and 1.05 that were available in spring 1983. Formaldehyde release measured with the 2 hr. U.S. desiccator test ranged from 8.6 mg/l to 0.3 mg/l after 6 weeks. European perforator standard values ranged from 80 mg/100 g to 9 mg/100 g. Low molar ratio resin produced MDF with good mechanical properties while yielding formaldehyde release rates that were sufficiently low to meet the requirement of the German wood product class E-1 and the 0.1 ppm requirement of ASHRAE 62-1981 or similar standards for minimum acceptable indoor air quality at reasonable product loading ratios.