五合板的燃烧特性及其动态和静态生烟特性

Flammability, static and dynamic smoke properties of plywood

利用热重分析仪(TGA)、差示扫描量热仪(DSC)、锥形量热仪(Cone)和塑料烟密度仪研究五合板的燃烧特性和生烟特性,并对燃烧特性与生烟特性的相关性进行分析。研究结果表明:五合板的热解过程可分为3个阶段,即干燥和粗挥发阶段、热解阶段和炭化阶段,其中热解过程为先吸热后放热的过程。五合板的动态烟释放(比消光面积、生烟速率和总生烟量)及静态烟释放(比光密度和质量光密度)与其燃烧过程有关且随着辐射功率的增加而增大,其中锥形量热仪实验中五合板的峰值生烟速率、总生烟量与峰值热释放速率之间存在较好的线性关系。五合板的静态生烟特性还受火焰条件的影响,其中相同辐射功率下有焰燃烧的比光密度和质量烟密度低于无焰燃烧条件下的,但质量损失却明显高于无焰条件下的。

The flammability and smoke properties of plywood were analyzed by thermo-gravimetric analyzer, differential scanning calorimeter, plastic smoke density tester and cone calorimeter. The correlations between flammability and smoke properties of plywood were revealed. The results show that the combustion process of plywood can be divided into three stages, i.e. dehydration and volatilization, pyrolyzation, and carbonization. An obvious endothermic process and an exothermic one were observed in procedure of plywood combustion. In addition, the higher level of external heat flux significantly increases the heat release rates, mass loss rates, dynamic smoke releases (specific extinction area, smoke production rate and total smoke production) and static smoke releases (special optical density and mass optical density).There are linear correlations between peak heat release rate and some dynamic smoke parameters (peak smoke production rate and total smoke production) in the cone calorimeter. Meanwhile, the application of an ignition source reduces both the mass and special optical densities, and increases the mass loss at the same incident heat flux.