Investigation of volatile organic compound press emissions during particleboard production. Part 1. UF-bonded southern pine

A method has been developed to collect and analyze volatile organic compoun d (VOC) press emissions during particleboard pressing, and to monitor the t emperature and vapor pressure at different locations within the mat. The wa ter solution of emissions trapped with two water scrubbers was analyzed for formaldehyde using the modified colorimetric method (5). Other VOC press e missions were extracted with methylene chloride and characterized and quant ified by gas chromatography/mass spectrometry (GC/MS). The amount of total VOCs (TVOCs) were quantified by combining the 70 largest CC/MS peaks, which comprise more than 97 percent of the total detected peak area of emissions . The TVOC emissions and the most prevalent chemical components (formaldehy de, pinenes, and hexanal) were investigated as a function of pressing varia bles. The pressing variables investigated were press temperature and time, mat moisture content (MC) and resin content, and board density. The results showed that the TVOCs emitted from the pressed boards accounted for about 20 percent of the volatile compounds contained in the wood extractives. Dif ferences in the TVOCs emitted from boards with or without urea-formaldehyde resin were insignificant. Formaldehyde emission increased with press tempe rature and time, mat resin content and MC, and board density. However, the TVOC emissions as a function of pressing variables did not follow easily di scernible trends. TVOCs increased with press temperature and board density, while the maximum TVOC emissions occurred at a mat MC between 10 and 14 pe rcent.