Selected volatile organic compound emissions and performance of oriented strandboard from extracted southern pine.
The impact of a hot water extraction procedure on select volatile organic compound emissions during pressing, as well as on properties of oriented strandboard (OSB) was evaluated. Southern pine strands were extracted with hot water using a rotating digester at 160°C for 22.9 or 53.6 min. Weight loss for the two extraction conditions was 6.3 ± 0.1% (short time) and 9.3 ± 0.9% (long time). The extract contained a mixture of hemicelluloses, acetic acid, and lignin. OSB panels were manufactured both with and without adhesive. The emissions (phenol, methanol, acetaldehyde, and formaldehyde) without adhesive present decreased from 38.2 to 24.2 mg/kg (oven-dry wood) as a result of the high severity factor (HSF) extraction. When adhesive was used, emissions totaled 22.1, 17.0, and 15.6 mg/kg (oven-dry wood) for control, low severity factor, and HSF, respectively. Water sorption and thickness swell were significantly reduced in panels made from extracted strands. Flexural modulus of elasticity of extracted panels exhibited significant increases in both dry and wet conditions. The flexural modulus of rupture and internal bond were slightly reduced in the dry condition as weight loss increased. The extraction procedure shows promise for improving a variety of properties of OSB, including performance, reduced environmental impact, and generation of a valuable chemical feedstock byproduct.
Keyword: Hemicelluloses, hot water extraction, weight loss, physical and mechanical properties, volatile organic compound, VOC
Paredes, J. J., Shaler, S. M., Edgar, R., & Cole, B. (2010). Selected volatile organic compound emissions and performance of oriented strandboard from extracted southern pine. Wood and Fiber Science, 42(4), 429-438.