Assessment of the fire risk rating for wood specimens coated with titanium dioxide/talc/water glass mixtures

摘要

Titanium dioxide/talc/water glass mixtures were applied to cypress wood typically used as an interior building material. Cypress is in the spotlight for its water repellency, light weight, and phytoncide release to improve health. The fire performance was investigated in terms of fire performance index-Ⅲ, fire growth index-Ⅲ, and fire risk index-Ⅳ culminating in a fire risk rating assessment using Chung's equations. The fire performance was measured using a cone calorimeter (ISO 5660-1). The external heat flux was fixed at 50 kW/m~2. Titanium dioxide was used as the metal oxide, and mixed with talc to increase the flame retardant effect. Titanium dioxide was differentiated into rutile and anatase because of their different structure. The fire performance index-Ⅲ measured after combustion was 3.2-12.0 times higher than that of the uncoated specimen. The fire growth index-Ⅲ was 2.9-36.4 times lower than that of the uncoated specimen and the fire risk index-Ⅳ of the coated specimens was 9.5-302.9 times lower than that of the uncoated specimens. Talc/water glass (TSS) and water glass (SS) were the safest materials using the fire risk rating FRI-Ⅳ. Rutile TiO_2 had a lower fire risk rating than anatase form. The CO concentration of the coated specimens was about 69-120 ppm and it was 1.2-2.1 times lower than the 147 ppm of the uncoated specimens.