防火电缆燃烧和毒性气体释放特性研究

Study on Combustion and Toxic Gas Release Characteristics of Flame Retardant Cables

采用锥形量热仪对外加辐射情况下以及涂覆防火涂料下的电缆热释放速率和毒性气体释放特性进行了研究。结果表明:对于未涂覆防火涂料、涂覆水性防火涂料以及溶剂型防火涂料的电缆,热释放速率随外加辐射强度的增大而升高。电缆燃烧毒性气体CO释放量随时间的变化趋势与热释放速率曲线基本一致,随着外加辐射强度的增大,CO最大释放率升高,CO平均热释放率也存在类似趋势。涂覆水性防火涂料的电缆热释放速率明显降低,涂覆溶剂型防火涂料的电缆热释放速率峰值变高,同时在燃烧后期其电缆热释放速率明显高于普通电缆。涂覆水性防火涂料的电缆CO释放率峰值及增长速率均明显减小,涂覆溶剂型防火涂料的电缆CO释放率明显升高。水性防火涂料可以有效延长电缆的引燃时间,而溶剂型防火涂料则会缩短电缆的引燃时间。从热释放速率、CO释放速率以及引燃时间角度分析,水性涂料对于电缆的燃烧强度以及CO释放量的抑制具有积极作用,阻燃效果更好。

The heat release rate （HRR） and toxic gas release characteristics of cables with flame retardant coatings under radiation were studied by cone calorimeter. The results show that the HRR of cables increases with the increase of external radiation, and the maximum and average CO release amount show the same change trend of HRR. The HRR of cables with waterborne flame retardant coating decreases obviously compared to the normal cable, while the HRR of cables with solvent flame retardant coating increases significantly, especially at the late stage of burning. The CO release amount and release rate of cables with waterborne flame retardant coating decrease obviously, and the CO release amount of cables with solvent flame retardant coating increases obviously. The waterborne flame retardant coating can effec- tively prolong the ignition time, while the solvent flame retardant coating would shorten the ignition time. According to the test results of HRR, CO release, and ignition time, the waterborne flame retardant coating has positive effects on the inhibition of cable combustion and CO release, and has better flame retardant effects.