Estimation of fire protection efficiency of articles made from reed under an external action of gasoline flame

Abstract

Our study into the process of reed ignition has established the mechanisms of heat transfer to a material, which makes it possible to influence this process. It has been proven that the process of ignition implies heating a material to the critical temperature when an intensive decomposition begins with the release of the required amount of combustible gases. Knowing this process makes it possible to determine the efficiency of fire protection and the properties of roofing compositions on the process of reed ignition deceleration. Under a thermal action on fire-proof samples, a swollen layer formed at the surface resulting from the decomposition of the retardants under the influence of the temperature, with the release of non-combustible gases that inhibit the oxidation processes of the material and substantially increase the formation of a thermoprotective layer of coke at the reed surface. This leads to an increase in the thickness of the coke layer and to the deceleration of heat transfer of high-temperature flame to the material. Given this, it has become possible to determine conditions for protecting reed from fire by forming a barrier to thermal conductivity. In addition, when applying a fire-proof coating, temperature influence is carried out in the direction of reactions in a pre-flame area towards the formation of ash-like products at the surface of the natural combustible material. That allows us to argue about feasibility of the established mechanism that forms the properties of fire protection of reed by swelling compositions and about practical significance of the proposed technological solutions. The latter, in particular, relate to determining the amount of a polymeric component as reed is characterized by hydrophobicity and an aqueous solution of the fire retardant flows down from the surface. Adding a PVA-dispersion leads to a decrease in the intensity of washing the flame retardant out of the material by larger than 6...8 times. Our experimental research has shown that when exposed to a gasoline flame the untreated model sample of a thermal insulation mat made from reed ignited on second 205, which led to its complete combustion while the flame-retardant sample did not ignite under thermal action, the flame did not propagate; in this case, we observed the swelling of a protective coating on the area of about 0.028 m2, which reached 3...4 mm. Thus, there is reason to argue about the possibility of targeted control over the processes that protect reed from fire by using an integrated roofing composition of a mixture of fire retardants, which contains a natural polymer capable of forming a fire-protective film on the surface of the material