STUDYING THE FIRE RESISTANCE OF MATERIALS BASED ON NATURAL AND SYNTHETIC FIBERS
Data is represented on the ignition of materials based on natural and synthetic fibers; the properties of some of them are described as exemplified by cotton, flax, wool, polyesters, and viscose. Thermal radiation is the most dangerous one of the fire factors. Influenced by thermal radiation, combustible materials can catch fire, which will lead to forming new fire spots. The greatest danger is burning the textile of the clothing cover layer, so studying the behavior of various materials of natural or synthetic origin under the influence of flame is an urgent task. The methods used to determine the fire resistance of various materials consist in assessing their flame resistance, are conducted for the inflammability, ignition easiness, combustibility (ignition rate), and may be reduced to identifying the practical applicability of a specific type of materials. The materials were chosen to detect the behavior of natural and synthetic fabrics, when they contact fire. Studying blended fabric allows identify the behavior of the synthetic component within the fabric construction as compared to the samples composed of purely synthetic or purely natural fibers. The comparative analysis is presented of the condition of textiles affected by highly intensive thermal flows. The test results have been presented of six material samples tested using the inflammability detecting installation. The experiment was performed in accordance with the Russian standard GOST 30402-96, using a burner. The analysis of behavior is presented for each type of materials, when affected by the thermal flow within 60 seconds. The time of approaching the burner to the sample under test made 1 s, the interval between the thermal flow exposures was 2 s. It is found that all samples ignited when affected by the thermal flow of 30 or 50 kW/m<sup>2</sup>. However, the ignition times were different. In the figures presented, the appearance of the samples under test is shown. Polyester was completely destructed due to fiber breakage. The samples of cotton, flax and blended fabric demonstrated the best results when exposed to open flame. Evaluation of the inflammability and ignition processes will help us realize the possible ways of enhancing the fire resistance of various materials.