Influence of loading factors on VOCs emission from veneered plywood

Polyvinyl chloride overlaid veneered plywood (PVC-VP), melamine-impregnated paper overlaid veneered plywood (MI-VP) and unfinished plywood (UF-P) were used as the experimental materials to explore the emission characteristics of volatile organic compounds (VOCs) and different VOC components from plywood under different loading factors. A 15L small chamber and gas chromatography-mass spectrometer were used as equipment. Under the conditions of a temperature of 23.5 °C ± 1 °C, relative humidity of 50% ± 5%, gas exchange rate of 1 h⁻¹, and loading factors of 1m²m⁻³, 1.5m²m⁻³, 2m²m⁻³, 2.5m²m⁻³, VOCs were collected from plywood on days 1, 3, 7, 14, 21 and 28 for analysis. The results showed that the loading factors had a greater impact on VOCs released from veneered plywood in the early stage, but a smaller impact in the later stage. However, loading factors influenced the middle and late stages of VOCs release from UF-P. Aromatic hydrocarbons account for the largest proportion in VOC components in plywood, and their decreasing rate increased with the loading factors. Polyvinyl chloride (PVC) and melamine-impregnated paper contain olefins and esters, which were released rapidly before the balanced period. The relationship between VOCs released from plywood and loading factors was nonlinear and affected by the use of decorative materials. Therefore, the fitting curves of PVC-VP, MI-VP and UF-P had different functional relationships due to the different surface decorations.