Effect of surface laminate type on the emission of volatile organic compounds from wood-based composite panels

Abstract

As a part of understanding the influence of wood-based panels on indoor air quality of a building, this study examined the effects of laminate type on the emission of volatile organic compounds (VOCs) such as formaldehyde, toluene, and total VOCs (TVOCs) from particle board (PB) and medium density fiberboard (MDF) panels, using a 20-L small chamber method. Five different types of surface laminates, including three types of surface overlays such as low pressure laminate (LPL), poly(vinyl chloride) (PVC) film, and urethane coated paper (UCP), as well as two types of surfaces coatings, i.e. direct coating (DC) and ultra-violet coating (UVC) were applied to the veneer bonded to a surface of PB and MDF panels that were of different grades with respect to formaldehyde emission (FE) such as E 0, E 1, and E 2 before surface lamination. As expected, the FE grade strongly affected the FE of panels, regardless of types of panel and laminate. All types of surface laminations dramatically reduced the FE compared to the control. However, the surface laminations by overlay significantly decreased the emission of TVOCs and toluene while both types of surface coatings greatly increased the emission of TVOCs and toluene. In particular, styrene was the main component of TVOCs from the DC sample (about 87%), while toluene was the main species of TVOCs from the UVC sample (about 73%). When two different ways of sample preparation (i.e., single- or all-surface exposure) were compared, the FE of the MDF sample was influenced by the surface exposure type. But TVOCs and toluene emissions were independent of the FE grade and the sample preparation. These results suggest that a proper selection of the surface laminate for wood panels has a significant impact on indoor air quality of a building.