Research into the physical and chemical properties of fire-retardant materials of structural elements of trucks running on gas engine fuel with the aim of increasing their fire-retardant efficiency

The fire load is an integral part of the fire hazard definition. Reducing this load is one of directions to fight fires in transport. To study the physicochemical processes and thermal effects occurring as a result of thermal decomposition of wood fire-proofed by retardants like BAN, OK-GF, OK-DS (OK-GFM), SPAD-0 and their chemical compositions, we used the methods of differential thermal analysis, thermogravimetry, and derivative thermogravimetry. In addition, to study the intensity of physicochemical combustion processes, tests to control changes in woodwork masses and temperature at the top of pipe depending on the duration of combustion of the samples and the consumption of fire retardants were conducted. Fire retardant compositions like OK-GF, OK-DS, Pirilax biopyrene at the consumption of 0.1 kg / m2 ensure flame and combustion resistance of the wood. The analysis of the research results confirmed the possibility of assigning to wood structures of a lorry’s body of the group 1 of flame and combustion resistance. Using the above fire retardants and their compositions in the treatment of lodgment elements and runners significantly affects the possibility and duration of the combustion process of a lorry. This was tested by means of an artificial fire source method (without chemical treatment, the burning time does not exceed 50 minutes). This significantly improves post-collision safety of vehicles with an increased fire load in terms of fire resistance because of using the natural gas as a motor fuel.

The Effects of Some Phosphorus-Containing Fire Retardants on the Properties of Glass Fibre-Reinforced Composite Laminates Made from Blends of Unsaturated Polyester and Phenolic Resins

This study investigated the effects of phosphorus fire retardants (FRs) in matrices from co-cured blends of an unsaturated polyester (UP) with inherently fire-retardant phenolic resoles (PH) on the mechanical and flammability properties of resultant glass fibre-reinforced composites. Three different phenolic resoles with UP have been used: (i) an ethanol soluble (PH-S), (ii) an epoxy-functionalised (PH-Ep), and (iii) an allyl-functionalised resin (PH-Al) with two different phosphorus FRs: resorcinol bis (diphenyl phosphate) (RDP) and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). The flammabilities of the resultant composites were evaluated using cone calorimetry and the UL-94 test. Cone calorimetric results showed reductions in peak heat release rate (PHRR) and total heat released (THR) as expected compared to those of UP and respective UP/PH composite laminates without FRs. UL-94 tests results showed that while all composites had HB rating, FR containing samples self-extinguished after removal of the flame. The mechanical properties of the composites were evaluated using flexural, tensile and impact tests. All FRs reduced the mechanical properties, and the reduction in mechanical properties was more severe in UP/PH-S (least compatible blends) composites with FRs than in UP/PH-Al (most compatible blends) composites with FRs. Amongst the different composites, those from UP/PH-Al with DOPO showed the best fire retardancy with little deterioration of mechanical performance.

The application efficiency of intumescent coatings for power cables of safety systems of nuclear power plants under fire conditions

Introduction. The reliable operation of safety systems, that allows for the failure of no more than one safety system component, entails the safe shutdown and cool-down of an NPP reactor in the event of fire. However, the co-authors have not assessed the loss of performance by an insulating material, treated by intumescent compositions and used in the power cables of the above safety systems exposed to the simultaneous effect of various modes of fire and current loads.Goals and objectives. The purpose of the article is the theoretical assessment of the application efficiency of intumescent fire-retardant coatings in power cables used in the safety systems of nuclear power plants having water-cooled and water-moderated reactors under fire conditions. To achieve this goal, the temperature of the outer surface of the insulation and the intumescent fire-retardant coating was analyzed depending on the mode of fire. Theoretical foundations. A non-stationary one-dimensional heat transfer equation is solved to identify the temperature distribution inside the multilayered insulation and the fire-protection layer of a conductive core.Results and their discussion. The co-authors have identified dependences between the temperature of the outer surface of the insulation and the fire retarding composition of the three-core cable VVGng (A)-LS 3x2.5-0.66, on the one hand, and the temperature of the indoor gas environment for three standard modes of fire and one real fire mode. It is found that before the initiation of the process of destruction of the insulation material, the intumescence of the fire-retardant coating occurs only in case of a hydrocarbon fire. Under real fire conditions, the maximal insulation melting time before the initiation of intumescence of the fire-retardant coating at the minimal temperature of intumescence is 4.75 minutes, while the maximal time period from the initiation of destruction of the insulation material to the moment of the insulation melting is 6.0 minutes.Conclusions. An experimental or theoretical substantiation of parameters of intumescent fire retardants, performed using standard modes of fire, has proven the potential loss of operational properties by insulating materials of power cables, used in the safety systems of nuclear power plants, in case of a real fire. Therefore, it is necessary to establish a scientific rationale for the efficient use of fire retardants in the above cables with regard for the conditions of a real fire.

Inhibitory action of halogen-free fire retardants on combustion and volatile emission of bituminous components

The objective of this study is to quantitatively evaluate inhibitory action of halogen-free fire retardants (HFR) on combustion properties and volatile emission of such bituminous components as saturates, aromatics, resins, and asphaltenes (SARA). Thermogravimetry-Fourier transform infrared spectroscopy (TG-FTIR) tests were performed on SARA fractions containing matched fire retardants, respectively, and thermal kinetics parameters based on TG curves and functional and structural indices from FTIR spectra were calculated, respectively. The selected fire retardants have not affected the combustion process of SARA fractions, but the combustion temperature intervals are elevated and combustion progresses are retarded. Also, the char yields of SARA fractions are obviously increased by the matched fire retardants, improving their heat stability. The activation energy is elevated because of the added fire retardants, indicating combustion resistance of SARA fractions become larger. Additionally, the matched fire retardants inhibit the toxic gas emission in the combustion process of SARA fractions, but have few effects on gaseous product constituents. H2O and CO2 are identified as two typical released gases in various combustion phases of each SARA fraction. Finally, the added hydroxide play a role of fire retardants through cooling, dilution, adsorption, and neutralization, and the generated active oxide facilitates the expandable graphite (EG) and matrix to form densified and thick carbon layer. These suppress the volatile emission, and hinder the heat conduction and oxygen supply. Fire retardant composite exhibits the synergistic effect of fire retardancy and smoke inhibition in the combustion process of SARA fractions.

Examination of the effect of fire retardant materials on timber

PurposeThe fire safety of structures is an existing and important design aspect, which is assured by strict regulations. As a means to adhere to the strict requirements, fire protection has become a core problem. It is particularly difficult to comply with these regulations in the case of timber, which is a combustible material. These problems could be solved by enveloping the wood in fire retardant materials. MSZ EN 1995-1-2 currently does not take into consideration the fire-retardant materials charring rate under fire exposure.Design/methodology/approachHowever, currently these fire retardants are proving to be reliable and depending on their application can achieve better reaction-to-fire classifications. During the research, the authors used five different fire-retardant materials on three different types of wood and tested their behaviours in a laboratory. When selecting them, it was important to choose the species that are most commonly used in the building industry but which have significantly different densities. Our choice fell upon spruce (360 kg/m3), Scots pine (540 kg/m3) and oak (650 kg/m3). During the tests, we examined the weight reduction and the process of burning on the specimens treated with the fire retardant material. In addition, the authors also performed tests by derivatography on both untreated and treated specimen.FindingsThe question is whether the effects of the fire retardants should be taken into consideration when calculating the extent of the burn. The Eurocode (MSZ EN 1995-1-2) does not provide any opinions. On the market, there are manufacturers who are already discussing the possibilities of reducing the burn rate during the qualification of paints. In this paper, based on the results we received, we discuss the beneficial effects of the fire retardants which can be taken into account while measuring cross-sections.Originality/valueBy using fire retardants, a high proportion of cross-sectional area gain is only possible in case of small cross-sections; therefore, it is advisable to use them here as well. This can be effective for example in many smaller cross-sections, when there is a little space and therefore requires a small cross-section. Thus, if a larger cross-section without protection is not possible, it can be replaced by a smaller cross section, treated with a fire retardant.

Physicochemical aspects of creating wood-based panels of low combustibility

С использованием концепций ингибирования горения древесного комплекса и образования древесных плит при горячем прессовании излагается авторское представление об основных аспектах создания плит пониженной горючести. Приводятся подходы к решению проблемы, раскрываются функции эффективных антипиренов, в том числе в их закрепляемости в древесных компонентах, температурном интервале активации, вариабельности кислотности среды. Анализируются параметры результатов испытания для оценки эффективности фосфорсодержащих антипиренов для древесных композиционных материалов (древесностружечных, древесноволокнистых и других). Предлагается развитие результата в направлении «сильного» решения и саморецензирование научного исследования. Using the concepts of inhibition of the combustion of a wood complex and the formation of wood-based panels during hot pressing, the author's idea of the main aspects of creating plates of reduced combustibility is presented. Approaches to solving the problem are given, the functions of effective fire retardants are revealed, including their fixation in wood components, the temperature range of activation, and the variability of the acidity of the medium. The parameters of the test results are analyzed to assess the effectiveness of phosphorus-containing fire retardants for wood composite materials (wood partcle board, fiberboard end other). The development of the result in the direction of a "strong" solution and self-review of scientific research is proposed.