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Article

Xiansheng Zhang, Xianjing Du, Lili Wang and Meiwu Shi

The purpose of this paper is to investigate the effect of char on the flame retardancy of fabrics by a cone calorimeter, which is an important factor to compare the flame…

Abstract

Purpose

The purpose of this paper is to investigate the effect of char on the flame retardancy of fabrics by a cone calorimeter, which is an important factor to compare the flame retardancy of different fabrics.

Design/methodology/approach

Cone calorimeter measurements were carried out in a Fire Testing Technology (UK) apparatus at the heat fluxes of 50 and 75 kW/m2. Fabrics with one and three layers were employed, with the name of cotton1, cotton3, FR cotton1, FR cotton3, PMIA1 and PMIA3. The dimension of the fabric was 100×100 mm2. A cross-steel grid was used to prevent the fabrics from curling during burning. The distance between the bottom of the cone heater and the top of the sample was 25 mm.

Findings

This work was generously supported by National Key R&D Program of China (Project No. 2017YFB0309000), Natural Science Foundation of Shandong Province of China (Project No. ZR2019BEM026), Natural Science Foundation of China (Project No. 51803101) and China postdoctoral science foundation funded project (Project No. 2018M632619).

Originality/value

The present research provides insight into the effect of the char formation on the flame retardancy of the fabrics, and a method to comprehensively investigate the char influence in the flame retardancy of the fabrics by a cone calorimeter is proposed.

Details

International Journal of Clothing Science and Technology, vol. 31 no. 4
Type: Research Article
ISSN: 0955-6222

Keywords

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Article

Saeed Bakhtiyari, Leila Taghi Akbari and Masoud Jamali Ashtiani

The purpose of this study is assessment of fire and smoke hazards of some fiber reinforced polymers (FRP). The use of FRP strengthening strips has been found rapid growth…

Abstract

Purpose

The purpose of this study is assessment of fire and smoke hazards of some fiber reinforced polymers (FRP). The use of FRP strengthening strips has been found rapid growth in construction industry of Iran and many other countries. However, the fire and smoke hazards of these materials in both construction and use phases need to be determined and the appropriated measures against fire should be taken.

Design/methodology/approach

The fire hazards of two types of fibre-reinforced epoxy composites (graphite fibre-reinforced polymer and carbon fibre-reinforced polymer) were investigated in bench-scale using cone calorimeter test method. Time to ignition, heat release rate, total heat release, smoke release and carbon monoxide production were measured and analysed. Time to flashover of an assumed room lined with the tested FRP was analysed with Conetools software. Smoke production and toxicity of the considered composites were also analysed and discussed, using the fractional effective dose parameter.

Findings

The results showed that the tested FRP products had a high fire hazard and a potential high contribution to fire growth. The tests also proved that the used epoxy resin had a low glass transition temperature, around 50°C; therefore, the mechanical strength of the product could be drastically reduced at first stages of a probable fire incident. This also showed that a regular thermal barrier, typically used for protection of plastic foams against fire, could not be sufficient for the protection of strengthening FRP composites.

Originality/value

This research was carried out for the first time for the materials used in construction industry of Iran. The results and achievements were very useful for safe use and development of proper details of application of the system.

Details

International Journal of Disaster Resilience in the Built Environment, vol. 8 no. 3
Type: Research Article
ISSN: 1759-5908

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Article

Md Delwar Hossain, Md Kamrul Hassan, Anthony Chun Yin Yuen, Yaping He, Swapan Saha and Waseem Hittini

The purpose of this study is to review and summarise the existing available literature on lightweight cladding systems to provide detailed information on fire behaviour…

Abstract

Purpose

The purpose of this study is to review and summarise the existing available literature on lightweight cladding systems to provide detailed information on fire behaviour (ignitibility, heat release rate and smoke toxicity) and various test method protocols. Additionally, the paper discusses the challenges and provides updated knowledge and recommendation on selective-fire mechanisms such as rapid-fire spread, air cavity and fire re-entry behaviours due to dripping and melting of lightweight composite claddings.

Design/methodology/approach

A comprehensive literature review on fire behaviour, fire hazard and testing methods of lightweight composite claddings has been conducted in this research. In summarising all possible fire hazards, particular attention is given to the potential impact of toxicity of lightweight cladding fires. In addition, various criteria for fire performance evaluation of lightweight composite claddings are also highlighted. These evaluations are generally categorised as small-, intermediate- and large-scale test methods.

Findings

The major challenges of lightweight claddings are rapid fire spread, smoke production and toxicity and inconsistency in fire testing.

Originality/value

The review highlights the current challenges in cladding fire, smoke toxicity, testing system and regulation to provide some research recommendations to address the identified challenges.

Details

Journal of Structural Fire Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2040-2317

Keywords

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Article

K.P.S. Cheng, W.K. Chow and S.S. Han

This study is to investigate the fire safety of textile and clothing materials. It also assesses the flammability for textiles in general.With the increase in big fires…

Abstract

This study is to investigate the fire safety of textile and clothing materials. It also assesses the flammability for textiles in general.

With the increase in big fires, accidental or non-accidental, people are worrying about the fire behaviour of combustibles. The flammability of textile and clothing materials is a great concern. Appropriate tests should be developed to assess textile and clothing materials to ensure they are safe in a fire. In fact, textile products should satisfy some fire safety criteria depending on their uses. There are specified flammability requirements on selected products, though whether these are good enough for assessing modern textile materials should be watched.

Typical textile materials with and without fire retardants protection were selected for assessing the fire behaviour with a cone calorimeter. High radiative heat flux up to 70 kWm‒2 was applied to assess those selected textile materials. A cone calorimeter is suggested to be the minimum requirement, though some full-scale burning tests are necessary for some purposes. Heat release rate and flame spreading measures are proposed in ranking the fire safety of textile materials.

Details

Research Journal of Textile and Apparel, vol. 10 no. 1
Type: Research Article
ISSN: 1560-6074

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Article

Ping Zhu, Chuanjie Zhang, Shuying Sui and Huaifang Wang

Alginate fiber with a breaking tenacity of up to 2.32 cN/dtex is prepared by spinning a sodium alginate solution in a coagulating solution of CaCl2 aqueous solution…

Abstract

Alginate fiber with a breaking tenacity of up to 2.32 cN/dtex is prepared by spinning a sodium alginate solution in a coagulating solution of CaCl2 aqueous solution followed by multi-roller drawing. Preparation parameters such as sodium alginate concentration, coagulant concentration and coagulation temperature, which affect the fiber tenacity, are investigated with an orthogonal test design, and the best spinning process is found with a coagulating 5% sodium alginate solution in 4% CaCl2 at 40°C. The morphology, degree of crystallinity, thermal stability and the combustion performance of this alginate fiber are investigated by scanning electron microscopy (SEM), infrared (IR), X-ray diffraction (XRD), Thermo gravimetric Analysis (TGA) and Cone Calorimeter. Using the centrifugal dewatering method, the absorption capacity of this alginate fiber is determined, and has a capacity of 13.01 grams of man-made blood per gram. The test results show that fibers have an irregular cross-section without a thicker cortex and uniform longitudinal surface with grooves. The combustion property results demonstrate that the fiber has a self-flameretarding property.

Details

Research Journal of Textile and Apparel, vol. 13 no. 4
Type: Research Article
ISSN: 1560-6074

Keywords

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Article

ChiaYuan Shih, YaoHan Chen, ChungHwei Su, ShiuanCheng Wang and YungChang Yang

The purpose of this paper is to analyze the phenomenon of makeup effect using numerical simulation and model experiments on seven different natural smoke extraction…

Abstract

Purpose

The purpose of this paper is to analyze the phenomenon of makeup effect using numerical simulation and model experiments on seven different natural smoke extraction patterns of tall space. Airflow distribution and heat accumulation phenomenon in different cases are compared. The natural smoke exhaust system for tall spaces has many advantages, including low cost, no power and low maintenance cost. It is more advantageous than the mechanical type of exhaust. However, the internal air distribution is complicated since the large span spatial character. Effective and correct verification method is very important for the analysis of flow fields in tall spaces.

Design/methodology/approach

This study used fire dynamics simulator (FDS) software to simulate the fire scene. The model experiments are conducted to determine if the numerical simulation results are reasonable. A single-mirror Schlieren system, including an 838 (H) × 736 mm (W) square concave mirror, as well as the focal length of 3,100 mm was adopted to record the dynamic flow of hot gas. Six smokeless candles were burned in a 1/12.5 model in experiments to record the distribution of inflow, accumulation and outflow of airflow in the space. In addition, the thermocouple lines were mounted in the model for temperature measurement.

Findings

The results of numerical simulation and model experiments have proved that makeup air has a significant effect on the effectiveness of a natural smoke vent system. Larger areas of smoke vents will produce more heat accumulation phenomenon. In this study, the air inlet and vent installed on the same side have a better heat removal effect. Moreover, Schlieren photography technique is proved to be an accurate measurement method to record the dynamic flow of hot air immediately, directly and accurately. The dynamic flow behavior of hot gas in the model has been visualized in this paper.

Originality/value

At present, there is no examination method other than checking the smoke vent area to validate the effectiveness of a natural smoke vent system in Taiwan, as well as no requirements regarding the makeup inlet. The effect of makeup air in generating the effective push-pull phenomenon of airflow has been analyzed. In addition, the post-combustion hot gas distributions were visualized by using Schlieren photography technology in the model space, compared with the FDS simulation result and thermocouple recorded temperature. A verification method in the model experiments is established to determine if the numerical simulation results are reasonable.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

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Article

ChungHwei Su and ShiuanCheng Wang

The purpose of this paper is to analyze the variations in the neutral plane when a tall space with unsymmetrical openings is on fire. The neutral plane of the fire scene…

Abstract

Purpose

The purpose of this paper is to analyze the variations in the neutral plane when a tall space with unsymmetrical openings is on fire. The neutral plane of the fire scene is an important index of a natural smoke exhaust system. The numerical simulation method and the Schlieren photography technique were used as analysis tools. The results of model experiments and numerical simulation were compared with each other to confirm the rationality of the conclusions. The results were to discuss the characteristics of various cases and showed that the neutral planes of the fire scene were not always horizontal.

Design/methodology/approach

The numerical simulation method and the Schlieren photography technique were used as analysis tools. The flow patterns of hot air in various cases were recorded using the flow visualization technique. In addition, the renowned simulation software, fire dynamics simulator (FDS), was used for case analysis. The Schlieren photography technique was used for 1/12.5 model experiments with six smokeless candles burned, and FDS was used for a numerical simulation. In terms of the case of unilateral vents, the exhaust efficiency was discussed when the exhaust vent and air inlet were located on the same side or different sides.

Findings

This study demonstrates that makeup air flowing in from the inlets and openings has a significant impact on the effectiveness of natural smoke exhaust systems. The results illustrated that the neutral planes were tilted in some cases. In some cases, the results showed that one side was the air inlet and the other side was the exhaust vent, even if the openings were at the same height in some cases. These phenomena have rarely been discovered or studied in the past. The exhaust efficiency was not always better when the vent was located in the rooftop.

Originality/value

This study analyzed the neutral plane of a fire scene using the common unsymmetrical opening spaces in the Taiwan region as an example. The phenomenon of non-horizontal neutral plane has rarely been studied in the past. The temperature of the discharged hot gas was low because of an efficient exhaust effect, which reduced the heat and smoke storage in the space. The results obtained by these two methods were consistent, and showed that the cases with the same opening area had different smoke extraction efficiencies, meaning the smoke extraction effect cannot be judged only by the opening areas.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 11
Type: Research Article
ISSN: 0961-5539

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Article

M. Grujicic, C.L. Zhao, S.B. Biggers, J.M. Kennedy and D.R. Morgan

Common Aero Vehicles (CAVs) are relatively small‐size, un‐powered, self‐maneuvering vehicles equipped with a variety of weapons and launched from space. One of the major…

Abstract

Common Aero Vehicles (CAVs) are relatively small‐size, un‐powered, self‐maneuvering vehicles equipped with a variety of weapons and launched from space. One of the major obstacles hampering a full the realization of the CAV concept is a present lack of lightweight, high‐temperature insulation materials which can be used for construction of the CAV’s thermal protection system (TPS). A computational analysis is utilized in the present work to examine the suitability of a carbon‐based, coal‐derived foam for the TPS applications in the CAVs. Toward that end, a model is developed for the high‐temperature effective thermal conductivity of foam‐like materials. In addition, an insulation sizing procedure is devised to determine the minimum insulation thickness needed for thermal protection of the vehicle structure at different sections of a CAV. It is found that the carbon‐based foam material in question can be considered as a suitable TPS insulation material at the leeward side and at selected portions of the windward side of a CAV (specifically the portions which are further away from the vehicle nose).

Details

Multidiscipline Modeling in Materials and Structures, vol. 3 no. 1
Type: Research Article
ISSN: 1573-6105

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Article

Santanu Basak, Kartick K Samanta, Sajal K Chattopadhyay, Rajesh Shashikant Narkar and R Mahangade

The purpose of this paper is to use the natural wastage plant product, bannana pseudostem sap (BPS) for using as fire retardant of cellulosic textile substrate. The study…

Abstract

Purpose

The purpose of this paper is to use the natural wastage plant product, bannana pseudostem sap (BPS) for using as fire retardant of cellulosic textile substrate. The study aims to use first time any wastage plant product for making fire retardant cellulosic textile. In this regard flame retardant functionality was imparted in cellulosic textile using BPS, an eco-friendly natural wastage product.

Design/methodology/approach

The extracted sap was made alkaline and applied in pre-mordanted bleached and mercerized cotton fabrics. Flame retardant properties of the control and treated fabrics were analyzed in terms of limiting oxygen index (LOI), horizontal and vertical flammability and total heat of combustion using bomb calorimeter. The thermal degradation and pyrolysis was studied using thermogravimetric analysis (TGA). The chemical composition of the control and BPS treated cellulosic fabric were analyzed by FTIR, SEM and EDX. Durability of the flame retardant functionality to soap washing had also been studied.

Findings

The study showed that the treated fabrics had good flame retardant property compared to control fabrics. The LOI value was found to increase by 1.6 times after application of BPS. As a result of this, the fabric does not catch flame. In horizontal flammability, the treated fabric showed burning with afterglow (without presence of flame) with a propagation rate of 7.5 mm/min, which is almost ten times lower than the control fabric. After application of BPS cellulosic fabric sample produced natural khaki colour. There was no significant change in other physical properties.

Practical implications

The application process is simple and cost-effective as no costly chemicals were used. Further advantage is that the treated fabric could also be considered as natural dyed cotton fabric. The developed khaki colour is quite attractive and stable to sun light exposure. This developed process could used in colouration and flame retardant finishing of home furnishing products such as home-window curtain, railway curtain, hospital curtain, table lamp and as a covering material of non-permanent structure like in book fair, festival, religious purpose, etc., where large quantity of textile is used and has chance of fire hazards.

Social implications

BPS abundantly available in Indian as well as other countries and it is normally considered as waste material. It is eco-friendly and produced from renewable source. Therefore, the application of BPS in cotton textile for colouration and functionalization will give the advantages of value addition using natural product. Rural people will be benifited lot by applying this technology whenever it required.

Originality/value

This paper helps to clarify first time why and how a wastage plant product like BPS can be used for preparing fire retardant cotton cellulosic fabric.

Details

International Journal of Clothing Science and Technology, vol. 27 no. 2
Type: Research Article
ISSN: 0955-6222

Keywords

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Article

E. Theuns, J. Vierendeels and P. Vandevelde

This paper describes a one dimensional moving grid model for the pyrolysis of charring materials. In the model, the solid is divided by a pyrolysis front into a char and a…

Abstract

This paper describes a one dimensional moving grid model for the pyrolysis of charring materials. In the model, the solid is divided by a pyrolysis front into a char and a virgin layer. Only when the virgin material reaches a critical temperature it starts to pyrolyse. The progress of the front determines the release of combustible volatiles by the surface. The volatiles, which are produced at the pyrolysis front, flow immediately out of the solid. Heat exchange between those volatiles and the char layer is taken into account. Since the model is used here as a stand‐alone model, the external heat flux that heats up the solid, is assumed to be known. In the future, this model will be coupled with a CFD code in order to simulate fire spread. The char and virgin grid move along with the pyrolysis front. Calculations are done on uniform and on non‐uniform grids for the virgin layer. In the char layer only a uniform grid is used. Calculations done with a non‐uniform grid are about 3 times faster than with a uniform gird. The moving grid model is compared with a faster but approximate integral model for several cases. For sudden changes in the boundary conditions, the approximate integral model gives significant errors.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 12 no. 5
Type: Research Article
ISSN: 0961-5539

Keywords

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