Abstract
It is well documented in the literature that temperature and humidity can influence formaldehyde emissions from composite panels that are produced using urea-formaldehyde (UF) adhesives. This work investigates the effect of temperature and humidity on newer, ultra-low emitting formaldehyde urea formaldehyde (ULEF-UF) and no-added formaldehyde (NAF) adhesives. A modified version of the EN 717-3 method to collect formaldehyde coupled with the acetyl-acetone method to quantify formaldehyde emissions was used. Formaldehyde emissions from a commercial CARB phase II compliant hardwood-plywood panel bonded with a ULEF-UF resin increased greatly when panels were exposed to higher heat and humidity. Furthermore, the rate of emission for ULEF-UF panels increased with longer exposure at 100% humidity. In contrast, formaldehyde emissions from CARB phase II compliant hardwood-plywood bonded with a NAF resin were relatively stable at different temperature and relative humidity conditions and decreased over time. This work highlights the potential for long-term formaldehyde emissions from the new ULEF-UF, CARB phase II compliant resin systems.
Keywords
Formaldehyde,
plywood,
adhesives,
glue,
temperature,
humidity,
composite materials,
environmental monitoring,
air pollution,
measurement,
hardwoods,
soybean glue,
heat,
emissions,
gluing,
exposure tests,
ASTM E 1333,
thermal degradation
Citation
Frihart, Charles R.; Wescott, James M.; Birkeland, Michael J.; Gonner, Kyle M. 2010. Formaldehyde emissions from ULEF- and NAF-bonded commercial hardwood plywood as influenced by temperature and relative humidity. In: Proceedings of the international convention of Society of Wood Science and Technology and United Nations Economic Commission for Europe--Timber Committee. 2010 October 11-14; Geneva, Switzerland. Paper WS-23: 13 p.
