Comparative Study of Fire Resistance and Char Formation of Intumescent Fire-Retardant Coatings Reinforced with Three Types of Shell Bio-Fillers

Three types of shell bio-fillers, including eggshell (CES), conch shell (CHS) and clamshell (CMS), were prepared by cleaning, ultrasonication and pulverizing processes of biowastes, and then applied to intumescent fire-retardant coatings. The effects of shell bio-fillers with different polymorphs on the fire resistance and char-forming of intumescent fire-retardant coatings were investigated by cone calorimeter test, fire protection tests, smoke density test, thermogravimetric analysis (TG), and the fire resistance and char-forming mechanism of bio-fillers in intumescent fire-retardant coatings were proposed. The results show that three kinds of bio-fillers exert an excellent synergistic effect on enhancing the fire resistance and char-forming properties of the intumescent fire-retardant coatings, while clamshell has the best synergistic efficiency among the bio-fillers. Especially, IFRC-CMS coating containing 3 wt% clamshell shows the best fire protection performance and lowest smoke production and heat release, which offers an equilibrium backside temperature of 134.6 °C at 900 s, a flame-spread rating of 14.4, and a smoke density rating value of 22.8%. The synergistic efficiency of bio-fillers in the intumescent coatings depends on the polymorphs of CaCO3 in bio-fillers, and aragonite CaCO3 shows a higher synergistic efficiency compared to calcite CaCO3 and the mixture of aragonite and calcite CaCO3. The CMS composed of aragonite shows the best synergistic effect, CHS composed of aragonite and calcite comes second, and CES composed of calcite has the weakest synergistic effect.

Comparative Study of Fire Resistance and Anti-Ageing Properties of Intumescent Fire-Retardant Coatings Reinforced with Conch Shell Bio-Filler

Conch shell bio-filler (CSBF) was prepared by washing, ultrasonicating, and pulverizing of conch shells and then was applied in waterborne intumescent fire-retardant coatings. The influence of CSBF on fire resistance and anti-ageing properties of intumescent fire-retardant coatings were studied by using different analytical methods. The fire protection and smoke density tests showed that when the mass fraction of CSBF was 3%, the resulting FRC3 coating had the optimum synergistic flame-retardant and smoke-suppression effects concomitant with a flame-spread rating of 10.7, equilibrium backside temperature of 152.4 °C at 900 s, and smoke-density rating value of 10.4%, which were attributed to the establishment of a more dense and stable intumescent char layer against heat and mass transfer. Thermogravimetric analysis indicated that the presence of CSBF increased the thermal stability and char-forming performance of the coatings, and the char residue of FRC3 rose to 34.6% at 800 °C from 28.6% of FRC0 without CSBF. The accelerated ageing test suggested that the incorporation of CSBF reduced the migration and decomposition of the flame retardants and the yellowing, blistering, and powdering phenomenon, thus improving the structural stability of the coating, resulting in better durability of flame retardancy and smoke-suppression performance.

Pemanfaatan IoT (Internet of Things) Dalam Monitoring Kadar Kepekatan Asap dan Kendali Pergerakan Kamera

Research has been carried out on the use of the Internet of Things in smoke density levels monitoring and camera movement control. Internet of Things as long distance communication for monitoring and control systems. In this research, the system can detect smoke levels and can monitor it via an android phone, besides this system is equipped with camera movement control so that the camera position can be controlled remotely to be positioned towards the center/source where smoke is detected, so this system is needed as building and industry security as a fire prevention. This study uses a smoke density detection sensor type MQ-2, Arduino Uno as a controller, Esp8266 as a Wifi module and a servo motor as a camera driver. The results of the tests that have been carried out prove that the system has been successfully integrated and works according to the target, which is to detect the concentration of smoke and monitor remotely via an android phone and camera movement control properly.

A Social Force Model for Pedestrians’ Movements Affected by Smoke Spreading

A social force (SF) model is proposed to simulate the egress of pedestrians while smoke is spreading. The advection-diffusion with source term is used to describe the propagation of smoke. It is incorporated into the SF model. The navigation field in our model is determined by the negative gradient of the solution of the Eikonal equation. It depends on the pedestrian and smoke density. Numerical experiments are performed in a room with multiple exits, and their results are shown.

Numerical Investigations on the Propagation of Fire in a Railway Carriage

In this study, advanced Computational Fluid Dynamics (CFD)-based numerical simulations have been performed in order to analyse fire propagation in a standard railway compartment. A Fire Dynamics Simulator (FDS) has been employed to mimic real world scenarios associated with fire propagation within railway carriages in order to develop safety guidelines for railway passengers. Comprehensive parametric investigations on the effects of ignition location, intensity and cabin upholstery have been carried out. It has been observed that a fire occurring near the exits of the carriage results in a lower smoke layer height, due to the local carriage geometry, than an identical fire igniting at the center of the carriage. This in turn causes the smoke density along the aisleway to vary by around 30%. Reducing the ignition energy by half has been found to restrict combustion, thus reducing smoke density and carbon exhaust gases, reducing the average temperature from 170 °C to 110 °C. Changing the material lining of the seating has been found to cause the most significant change in output parameters, despite its relative insignificance in bulk mass. A polyester sample produces a peak carbon monoxide concentration of 7500 ppm, which is 27× greater compared with nylon. This difference has been found to be due to the fire spread and propagation between fuels, signifying the polyester’s unsuitability for use in railway carriages.

Modification of Interaction Forces between Smoke and Evacuees

The most used fire effect models on evacuees are only focused on the physical capacity of the evacuees. However, some of the evacuees in a fire situation continuously move through the familiar route, although the familiar route is smoke-filled and they know that they are moving towards the fire source. Thus, the additional evacuation models are required for considering the behavioral changes due to the psychological pressure when the evacuees are moving through the smoke or towards the fire source. In this study, the inner smoke region force is modified to improve the accuracy and practicality of the BR-smoke model by varying the walking speed according to the smoke density. Additionally, the BR-smoke model is applied to FDS+Evac to compare the simulation results of the modified BR-smoke model with those of existing models. Based on the results, the evacuation characteristics inside the smoke region can be improved by using the modified BR-smoke model because the evacuees are continuously influenced by the modified inner smoke force inside the smoke region. However, additional studies for determining more reliable evacuee psychological factors are required to improve the reality of the modified BR-smoke model.

Impact of graphene oxide on epoxy resin characteristics

The incorporation of a small part of graphene oxide (GO) offers an appropriate fire retardant for thermally conductive epoxy (EP) resin composites, which is verified by the upper limiting oxygen index of 24.5% and other standard flame-retardant tests. The smoke production rate, total smoke production (TSP), and the smoke density of EP composites were reduced with additional GO. The increased efficiency of fire resistance and smoke suppression is primarily due to the formation of physical barrier and compactness of the developed GO char layers, serving as an effective barrier layer that increases the fire resistance, and the thermal steadiness of the char layers derives from the effect of GO inclusion. The barrier impact of GO and the limited mobility of polymer chains are crucial factors in increasing thermal stability and reduction of generating dangerous carbon monoxide during burns. The thermal stability increased and the peak heat release rate, total heat release, TSP, and the largest smoke density value reduced to 52.5%, 43.6%, 33.9%, and 44.2%, correspondingly, compared with pure EP. The tensile strength and elongation at break of EP composites were enhanced by 23% and 8.4% compared with pure EP, respectively.