Study of Selected Natural Materials Ignitability

Abstract

This scientific study deals with a complex research of initiation process of selected natural materials. The first chapter deals with research of the influence of density and thermal modification of spruce wood (Picea abies(L.) Karst.) on the critical heat flux density for the pilot ignition. In this chapter the thermally modified and unmodified samples of a spruce wood were investigated. The thermally modified samples were prepared according to temperature program for the ThermoWood - Thermo-S (maximum temperature during the thermal modification was 190 °C) and ThermoWood - Thermo-D (the maximum temperature during the thermal modification was 212 °C) production. Critical density of heat flux was determined on a cone calorimeter test by procedures in accordance with ISO 5660-1:2002. The obtained results showed that the thermally modified spruce wood in comparison with the thermally unmodified one had higher critical density of heat flux. The second chapter is aimed on determination of ignition activation energy of pure cellulose, cellulose impregnated by water solutions of KHCO3and (NH4)2HPO4with concentrations of 5, 10 and 15 wt. % and on determination of ignition activation energy of dust from beech wood (Fagus sylvaticaL.). The activation energies were determined in accordance with isothermal, dynamic and non-isothermal model-free methods. The obtained results showed that the ignition activation energy of cellulose impregnated by water solutions of KHCO3and (NH4)2HPO4have lower activation energy than the pure cellulose. The obtained data on the activation energy of beech wood dust showed that the activation energy depends significantly on the degree of conversion. Chapter three deals with the research of inclination of selected vegetable oils (Linseed, Sesame and Sunflower oil) applied to cotton to self-ignite. The propensity towards spontaneous combustion of the mentioned oils was investigated by Mackey test and Accelerating Rate Calorimetry. The results showed that the ratios of oil mass to the mass of the carrier, on which oil is applied, had significant impact on the propensity of vegetable oil to the spontaneous combustion. The highest propensity to spontaneous combustion of the investigated materials showed the Linseed oil.

Wood of Coniferous Trees: Reaction to Fire

“…In the initial stage, analysis, comparison, and synthesis were used, whereas in the final phase, the methods of induction and deduction, comparison and subsequent formulation of regularities of the given phenomena have been applied [17].…”

Modified Method of Evaluation the Effect of the Protection Retardant Coatings Applied on the Surface of the Wood Building Construction

“…The evaluation criteria for assessing the behaviour of wooden products surface treatment by polyurethane coatings (solvent and water soluble) during the thermal degradation of utilizing radiant heat source: weight loss are calculated on the basis of equation ( 1) and the speed of the burning on the basis of equation (2). The results of experimental determination of test specimens thermal degradation parameters, according to the evaluation criteria, are shown in Table 3.…”

“…One of the most common ways of retardation treatment is the application of protective retardant substances [1,2], which should favourably modify the resulting fire-technical characteristics of wood, designed for wood constructions. In our paper we deal with an experimental assessment of selected retarding substances affect (HR-Prof, PLAMOSTOP D and D PLAMOSTOPtransparent), which were applied to the surface of solid spruce wood, and further thermally loaded with a radiant heat source.…”