表面结皮对喷涂聚氨酯泡沫燃烧性能的影响

摘要

选取不同的喷涂聚氨酯泡沫,采用《建筑材料或制品的单体燃烧试验》方法测量热释放速率指数FIGRA、热释放速率HRR、总热释放量THR、烟气生成总量TSP和烟气生成速率指数SMOGRA,研究其带表面结皮和不带结皮时的燃烧特性.样品厚50 mm,喷涂在12 mm厚硅钙板标准基材上,一组为喷涂后保留自然发泡形成的表面结皮,一组切削掉表面结皮.通过对试验结果的分析,发现保留表面结皮层的喷涂聚氨酯泡沫在热释放速率、总热释放量、烟气生成速率等数据明显差于切除表面结皮层的相同试样,表明喷涂聚氨酯泡沫结皮层比芯层阻燃程度低,在工程施工时应加强对喷涂聚氨酯泡沫结皮层的火灾风险控制,同时在对其防火性能进行评估时,应切除表面结皮层以反映该材料本身的性质.%Several different sprayed polyurethane foams with and without surface crust were employed to study their combustion properties.The fire growth rate (FIGRA),heat release rate (HRR),total heat release(THR),total smoke production (TSP) and smoke growth rate(SMOGRA) were tested by sin gle building items (SBI) technology in Single burning item test for building materials and products.The polyurethane foam was sprayed on the calcium silica board with 12 mm in thickness.The samples were 50 mm in thickness with or without surface crust.The experiments results showed that sprayed polyure thane foam with surface crust has lower HRR,THR and SMOGRA than the samples without surface crust.The crust has lower degree of flame retardant than the core,which indicates that we should strengthen the fire risk control during the process of construction.In the meanwhile,to evaluate the nature fire performance of sprayed polyurethane foam,surface crust must be removed.