Emissions Characteristics of Formaldehyde from Block Board
细木工板中甲醛释放特征及规律

Environment testing chamber of HJC-1 type was used to simulate the indoor environment of block board widely used in buildings adopted as the tested material. Formaldehyde concentrations in the chamber at different board structures, air exchange rates, relative humidities and environmental temperatures in a certain period were measured, and analyzed in its diffusion mechanism. Gray-system forecasting model was established to predict the concentration of formaldehyde, after its emission from the board at peak value. The results indicate that the main emission channel of formaldehyde is the side surface of board, it releases 3 times of formaldehyde quantity as the surface of board. Formaldehyde gas diffusion process is divided into three stages, the initial fast release, stable release and long-term slow release. Air exchange rate affects the formaldehyde concentration in the testing chamber, but does not affect its release rate of block board; the formaldehyde concentration increases with the increase of relative humidity and temperature. The predicted data of forecasting model agree well with the experimental data. The average relative error is 3.717%. This method is suitable for long term prediction.