Harangózo, JozefTureková, Ivana2023-06-222023-06-2220231336-00192730-0544http://drepo.uniza.sk/handle/hdluniza/875The paper studies the effects of heat flow on the flammability of wood materials when flame retardants are applied. Beech and spruce wood samples were treated with phosphorus- and carbon-based flame retardants, namely NH4H2PO4 and KHCO3 salts. Retarders were applied by spraying them on the surface of the samples. After their thermal stabilization, the parameter time until the sample ignited when exposed to the action of a radiation panel set to a maximum power of 15 kW was investigated. The results were recorded at different distances of 50, 70, and 100 mm from the radiation panel. KHCO3 was identified as the retarder with the highest efficiency based on the obtained measurements. Thermal decomposition analysis indicated that the improvement in flame retardancy of the treated wood was achieved by dehydration of the polysaccharides and the formation of a protective char shield due to the cessation of heat and oxygen transfer.czhttp://creativecommons.org/licenses/by/4.0/heat flowflame retardantsbeech woodspruce woodArticlehttps://doi.org/10.26552/krm.C.2023.1.22-27