REDUCING THE FORMALDEHYDE EMISSION OF COMPOSITE WOOD PRODUCTS BY COLD PLASMA TREATMENT

摘要

Free formaldehyde which releases from composite wood products in the indoor environment causes tremendous harm, to the human health. Researchers from the entire world have made unremitting endeavor to reduce the formaldehyde emission of composite wood panels. This study evaluates the formaldehyde emission of plasma pretreated plywood and MDF panels. The desiccator test method was used to evaluate the formaldehyde emission. The results show that cold ammonia plasma treatment can reduce the formaldehyde emission of plywood panels by 35 to 40 % and cold air plasma treatment by 9 to 17 %. Formaldehyde emission of coated medium density fiberboard panels can also be reduced by cold air and ammonia plasma treatment by 21 and 31 %, respectively. It is exciting to find that cold plasma treatment as an efficient and ecosystem friendly method, which is completely different from traditional formaldehyde reducing methods, can reduce the formaldehyde emission greatly and increase material stability without decreasing and even increasing the wet bonding strength of the UF resin.