Cone Calorimeter Method Research Articles

Thermal and Combustion Properties of Biomass-Based Flame-Retardant Polyurethane Foams Containing P and N.

Biomass has been widely used due to its environmental friendliness, sustainability, and low toxicity. In this study, aminophosphorylated cellulose (PNC), a biomass flame retardant containing phosphorus and nitrogen, was synthesized by esterification from cellulose and introduced into polyurethane to prepare flame-retardant rigid polyurethane foam. The combustion properties of the PU and PU/PNC composites were studied using the limiting oxygen index (LOI), UL-94, and cone calorimeter (CCT) methods. The thermal degradation behavior of the PU and PU/PNC composites was analyzed by thermogravimetric analysis (TGA) and thermogravimetric infrared spectroscopy (TG-IR). The char layer after combustion was characterized using SEM, Raman, and XPS. The experimental results showed that the introduction of PNC significantly improved the flame-retardant effect and safety of PU/PNC composites. Adding 15 wt% PNC to PU resulted in a vertical burning grade of V-0 and a limiting oxygen index of 23.5%. Compared to the pure sample, the residual char content of PU/PNC15 in a nitrogen atmosphere increased by 181%, and the total heat release (THR) decreased by 56.3%. A Raman analysis of the char layer after CCT combustion revealed that the ID/IG ratio of PU/PNC15 decreased from 4.11 to 3.61, indicating that the flame retardant could increase the stability of the char layer. The TG-IR results showed that PNC diluted the concentration of O2 and combustible gases by releasing inert gases such as CO2. These findings suggest that the developed PU/PNC composites have significant potential for real-world applications, particularly in industries requiring enhanced fire safety, such as construction, transportation, and electronics. The use of PNC provides an eco-friendly alternative to traditional flame retardants. This research paves the way for the development of safer, more sustainable, and environmentally friendly fire-resistant materials for a wide range of applications.

Life cycle assessment of glass/polyester laminates used in the shipbuilding industry and its fire behavior

The aim of this study is to assess the environmental performance of the manufacturing process of glass/polyester laminates as well as estimate their fire behaviour and smoke release. The Life Cycle Assessment was conducted according to the ISO14040/44 standard by using the CML-IA 2000 Baseline Midpoint method. The cone calorimeter study was conducted using a cone calorimeter method according to ISO 5660. The tests were performed under 25 kW/m2 heat flux 50 kW/m2. The results showed that according to the requirements of the Fire Test Procedure (FTP) Code examined, laminates in this form cannot be used in some applications. The LCA study showed that the highest impact is attributed to marine aquatic ecotoxicity (88.3%), with the highest contribution of the unsaturated polyester resin and the glass fibre.

Investigation of the heat release rate and particle generation during fixed bed gasification of sweet sorghum stalk

Sweet sorghum (SS) is an agricultural crop that is produced commercially in Nigeria. The crop has a high biowaste energy in its stalk, which is an attractive source of bioenergy in rural areas where it is produced. The residue–to-produce ratio (RPR) of the crop is 1.25 kg of biowaste for 1 kg of SS produced. The solid residue that results from the crop can be subjected to gasification to produce combustible gases: carbon monoxide (CO), hydrocarbon gases (total hydrocarbons) and hydrogen. The combustible gases can be piped into a burner for heat or into a Compression Ignition (CI) engine for electricity generation. This will enhance energy security as well as energy equity in rural areas in Nigeria and sub-saharan African countries where the crop is also produced. This research was aimed at optimising the gasification of SS stalk residue to maximise the yield of combustible gases from the first stage of the process. The restricted ventilation cone calorimeter method was used to gasify SS stalks on a laboratory scale. The test was carried out at air flow rates per exposed flat surface area of 9, 11.2, 12.9, 14.3, 15.5, 16.3, and 19.2 g/s·m2 respectively, which controls the gasification rate or power output. The speciation of the gases that evolved from the gasification of the biomass samples was carried out by an FTIR that was calibrated for 60 species. Current uses of biomass residues in open fire heating generates toxic fine particulate emissions and this work aimed to show that this was not a greater problem with gasification. A dynamic electrical mobility particle spectrometer (DMS500) was used to measure the particulate size distribution and concentration, as an efficient gasifier should not be generating major yields of soot, which would be a problem for a downstream reciprocating engine. The optimum equivalence ratio (Ф) for the best energy transfer to the gaseous products was 2.1, which was similar to previous work on pine using this equipment where the optimum equivalence ratio was 2.8. The hot gases efficiency at the optimum Ф was 81%, which compares well to that of 78% for pine.

Analysis of the Influence of Organophosphorus Compounds and of Aluminium and Magnesium Hydroxides on Combustion Properties of Epoxy Materials

This paper presents the influence of selected flame retardant additives on heat release rate and thermokinetics properties of epoxy materials made of epoxy resin—Epidian 5. The epoxy resin underwent flame retardant modification with the use of organophosphorus compounds (Roflam F5, Roflam B7) and Al(OH)3, Mg(OH)2. The fire characteristics of the analysed epoxy resin were determined using the cone calorimeter method, and thermal analysis of epoxy resin and the surface morphology of the analysed epoxy materials was with the use of an SEM microscope with an EDS attachment. The lowest value of the heat release rate was recorded for hardened epoxy resin containing one component additive 5% by weight of Mg(OH)2, as well as two component additive 10% by weight of Roflam F5 and 5% by weight of Al(OH)3. Moreover, the initial temperature of thermal decomposition of phase I of the modified epoxy resin samples with Mg(OH)2 (sample 5M) or organophosphorus compounds and Mg(OH)2 (samples 5B + 10M and 5F + 10M) were higher compared to the unmodified epoxy resin for these samples. Considering the surface morphology of the samples with Mg(OH)2, it can be concluded that the additives cause a homogeneous charred layer.

Effect of a graphene-APP composite aerogel coating on the polyester fabric for outstanding flammability

Catalytic charring is an important way to realize flame retardant modification of polymer, especially for carbonaceous polymers. In this paper, graphene aerogel (GA) as a new carbon carrier, and ammonium polyphosphate (APP) as catalyst, an efficient integrated composite aerogel (GA-APP) is constructed and in situ grown on the surface of polyester fabric by the hydrothermal reduction method. The flame retardancy and mechanism of GA-APP has been investigated in detail by limiting oxygen index (LOI), x-ray photoelectron spectroscopy (XPS), thermogravimetry-infrared (TG-IR) and cone calorimeter (CONE) method. The results showed that, with the addition of 26 % GA-APP powder, the LOI value of GA-APP/PET fabric is 34.1 %, and the vertical combustion test passed B1 grade. GA-APP flame retardant significantly reduced the peak heat release rate, total heat release, total smoke production and smoke rate of PET fabric through the synergistic effect of GA and APP. The char residual amount of GA-APP/PET fabric increased to 91.5 % after the combustion during the CONE test. GA-APP mainly played the role of agglomerative flame retardant by changing the char structure and char quantity, which can function the stronger barrier effect and inhibit the combustion reaction. The dense and carbon layer with high thermal stability formed under the synergistic action of GA-APP. This layer can isolate heat transfer, flame retardant and smoke suppression during PET fabric combustion.

Prediction of Smoke Risk Ratings in the Combustion of Different Species of Wood

In this study, smoke performance index-V and smoke growth index-V were calculated to expand Chung's equations 1, 2, and 3 and to standardize smoke hazard rating evaluation in case of fire. For this purpose, six types of wood were selected and measured by the cone calorimeter method according to ISO 5660-1. Also, overall, smoke risk was graded by smoke risk index-VI according to Chung's equation-VI. As a results, smoke hazard index-VI was found in the order of oyster oak (0.03) ≈ chestnut (0.04) ≈ zelkova (0.08) < PMMA (1.00) < pitch pine (3.13) < spruce (10.08) < lauan (11.65). Therefore, it was predicted that oyster oak, chestnut, and zelkova had the lowest smoke risk, and lauan had the highest. However, the average concentration of carbon monoxide in the specimen is 53-142 ppm, which is higher than the OSHA limit (PEL), it is concerned that it will harm health.

Assessing the combustibility of claddings: A comparative study of the modified cone calorimeter method and cylindrical furnace test

SummaryA cone calorimeter, a standard device to measure the fire reaction properties of materials, is modified in this study to investigate its potential to replace the cylindrical furnace test method to assess the combustibility of cladding materials used in buildings. The modification allows cladding materials to be evaluated under conditions closer to their end‐use configuration than the current testing condition in the cylindrical furnace test. In addition, the modified cone calorimeter method provides more quantitative data on the fire reaction properties of the cladding materials compared to the passed/failed indicator in the cylindrical furnace test. Comparative studies between modified cone calorimeter and cylindrical furnace test results for four types of cladding with different combustibility properties are performed. The surface temperature, time‐to‐ignition, and flaming duration values measured for the claddings using the two test methods are similar, leading to the same classification based on AS 1530.1 standard. Other fire reaction properties of the claddings can be measured using the modified cone calorimeter method, which is not possible with the cylindrical furnace test, including mass loss rate, heat release rate, and smoke production, which are particularly dependent on the formation of a ceramic‐like carbonaceous layer of tested samples.

A modified specimen holder for cone calorimeter testing of composite materials to reduce influence from specimen edges

SUMMARYISO 5660‐1 specifies the cone calorimeter method for characterizing the ignition and surface burning behavior of materials. The specimen is irradiated through a square opening in the frame of the specimen holder. The frame is intended to protect the edges of the specimen from irradiation but covers the edges with only a few mm. In tests with products such as composite laminates and sandwich wall panels, the production of pyrolysis gases from the edges and, in many cases, burning have been observed. Early contribution from the edges in the test is not representative for surface burning. A modified specimen holder was developed with a larger specimen size to allow better protection of the edges. The opening for exposure to irradiance of the retainer frame is circular and of the same area as that of the original frame. The distance between the exposed surface and the specimen edges is larger in order to prevent early exposure of edges. Tests using the standard specimen holder resulted in pyrolysis and burning from edges that took place outside of the specimen holder. Comparative tests using the modified specimen holder showed that it prevented the exposure and pyrolysis from edges for an extended time. However, the influence on ignition time and peak heat release due to the increased size of the modified specimen holder has not been characterized fully, and test results should not be used for direct comparison with those of the standard holder.

Fire Properties of Acrylonitrile Butadiene Styrene Enhanced with Organic Montmorillonite and Exolit Fire Retardant

In this paper an experimental investigation on fire retardancy of a new polymer nanocomposite derived from organic montmorillonite and exolit fire retardant in an acrylonitrile- butadiene-styrene copolymer by analyzing the flammability and fire behavior is described. The samples were prepared by melting and mixing nanocomposites and fire retardant in different concentrations in an acrylonitrile-butadiene-styrene base polymer. It was found that using only one component (organic montmorillonite or fire retardant) the burning stops in 10 s on the sample. Confirmation of synergy in flammability by combining both montmorillonite and flame retardants was noticed and is discussed regarding the flame-retardant mechanisms assessed by means of the Limiting oxygen index (LOI), UL 94, and cone-calorimeter methods. The acrylonitrile- butadiene-styrene preparation with 15–20 wt% fire retardant and 1–2 wt% organic montmorillonite reached a UL-94 V-0 classification, contrasting with the pure acrylonitrile- butadiene-styrene and the acrylonitrile-butadiene-styrene with 15 wt% fire retardant and acrylonitrile-butadiene-styrene with 1–2 wt% organic montmorillonite formulations, which completely burned. Finally, the samples showed a very good synergy going to a higher reduction of the peak heat release rate and to a minimum mass reduction, as obtained from cone calorimeter tests.

Role of caged bicyclic pentaerythritol phosphate alcohol in flame retardancy of PA6 and mechanism study

ABSTRACTA series of PA6/PEPA composites were prepared by mixing caged bicyclic pentaerythritol phosphate alcohol (PEPA) and polyamide 6 (PA6) at different feed ratios by the melt‐blending method in a twin‐screw extruder. The influence of PEPA on the flame‐retardant properties of PA6 was investigated using the limiting oxygen index (LOI), the Underwriters Laboratories UL‐94 test, and the cone calorimeter method. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, X‐ray photoelectron spectroscopy, thermogravimetry (TG), and TG‐FTIR were conducted to study the influence of PEPA on the thermal decomposition and the mechanism of performance of PA6 from products of condensed and gaseous phases. The results show that the LOI value and the content of residual char of PA6/PEPA composites increased with increasing PEPA content, and an LOI value of 38% could be reached when the feed ratio of PEPA was 30 wt %. The average heat release rate and total heat release drastically decreased with increasing content of PEPA, and the amount of carbon residue increased by 52.9% over neat PA6 after TG tests. The inorganic acid produced by PEPA during combustion can be used as an acid source to promote the dehydration of PA6 and the processes of esterification crosslinking, arylation, and carbonization. Moreover, there was less CO2 released than by PA6, and more carbon‐containing compound remained in the composites so that a stable carbon layer structure was formed. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46236.

Influence of nanoparticle geometry on the thermal stability and flame retardancy of high-impact polystyrene nanocomposites

Nanocomposites of high-impact polystyrene (HIPS) with three types of nanoparticles, namely layered organically modified montmorillonite (OMMT), tubular multi-walled carbon nanotubes (MWNTs) and spherical silica nanoparticles, were prepared by melt blending method. The influence of nanoparticle geometry on the thermal stability and flame retardancy of HIPS nanocomposites was investigated by transmission electron microscopy, thermo-gravimetric analysis, cone calorimeter method and scanning electron microscopy. The results show that the presence of three types of nanoparticles with varying geometries does not change the degradation mechanism of the nanocomposites, but greatly decreases the heat release rate and mass loss rate of the materials due to the fire residue formed in the condensed phase. The layered structure of OMMT exhibits the best flame-retarded effect, and the tubular structure of MWNT obtains a weaker flame-retarded effect and the spherical structure of silica nanoparticles the weakest. The effectiveness of flammability reduction is varied with nanoparticle geometries due to the discrepancies in featured structures of fire residues formed in real fire conditions. The idealized models of the featured structures of fire residues from the nanocomposites studied are put forward to explain the flame-retardant mechanism of the nanoparticles with different geometries.

Universal evaluation of fire retardant properties of fiber mats by the optimal cone calorimeter

By using the optimal cone calorimeter, the universal method to study the fire retardant properties of fiber mats with different categories was explored. The challenge in obtaining accurate and repeatable cone calorimeter data was overcome from two aspects, employing a specific fixing mode and optimizing the measurement parameters. It was confirmed that the optimal grid covering rate of 25% and sample weight of 6 g favored repeatable and reliable data. With the improved cone calorimeter method, the reactions to fire of the selected fibers, involving the common and the inherent fire retardant fibers, are analyzed under different heat fluxes, in which the variations of time to ignition, the heat release rate and total heat release were compared. The fire retardant properties of various fiber mats were efficiently obtained by the improved cone calorimeter, which in turn verified its universality. In addition, the comparison between fire retardant properties and heat resistance of fibers demonstrated that the heat resistance is not the sole factor determining the fire retardant performance; the released fuel is much more important than the decomposition temperature. In conclusion, the universal evaluation method for combustion performance of fiber mats by the optimal cone calorimeter has been successfully established, which can serve as an efficient way in predicting the fire retardant properties of the corresponding fabrics.

Flame retardant and smoke suppression mechanism of multi-walled carbon nanotubes on high-impact polystyrene nanocomposites

Nanocomposites of high-impact polystyrene (HIPS) with multi-walled carbon nanotubes (MWNT) were prepared by melt blending method. The flame retardant and smoke suppression mechanism of MWNT on HIPS were intensively investigated by transmission electron microscopy (TEM), thermogravimetric (TG) analysis, cone calorimeter method, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). It was found that the addition of MWNT has no marked effect on the degradation mechanism of the nanocomposites, but it significantly reduces the smoke production rates, total smoke release, smoke factor, heat release rates and mass loss rates of the material and forms a considerable volume of residue after burning. The flame retardant and smoke suppression mechanism are due to the formation of residue with featured structure during combustion. The fine morphology of the residues for the composites showed that the residues of HIPS/MWNT nanocomposites assume a two-layer structure in sub-microscale and micro network structure in nanoscale. The two-layer structure includes a thin skin layer at the surface of the residue and an expanded cellular layer beneath the skin layer. It is the skin-cellular layer structure which considerably enlarges the thickness and volume of residue. Both the skin layer and cellular layer are constituted of MWNT, which are interconnected to form a network-like structure in nanoscale. It is a well combination of the skin-cellular layer and the nanoscale network structure that acts as a good insulation barrier to reduce flammability and smoke production of the composites.

Research of Effectiveness of „Plamostop“ Fire Retardand and Suitability of Testing Methods for Wood Flame Retardants Evaluating

Abstract The paper deals with testing of a water-miscible intumescent fire retardant. Experiments are conducted by thermal analysis (TG/DTG, DSC), cone calorimeter and non-standardized methods for monitoring weight loss when exposed to flame burning. Based on the experiment results and other information the most appropriate methods for testing fire retardants are reviewed. All methods by which experiments have been carried out are described. Our own method for testing fire retardants was created. It is also evaluated the effectiveness of a representative fire retardant of wood by all mentioned methods. The result of the experiment is to evaluate the suitability of each method for testing of fire retardants and evaluation fire retardant “Plamostop”.

Development of a Halogen Free Flame Retardant Masterbatch for Polypropylene Fibers

The efficiency of new phosphinates, in combination with melamine cyanurate, was studied using different polypropylene textile structures. The influence of different ratios up to a total amount of 6 wt% in the polypropylene fiber was investigated using the limiting oxygen index (LOI) and cone calorimeter method for research purposes, while the performances were correlated to the standards FMVSS 302 (Federal Motor Vehicle Safety Standards) and DIN 4102-l (Deutsches Institut für Normung) used more specifically for automotive and building sector.

The effect of recycled plastic aggregate on chemico-physical and functional properties of composite mortars

In this paper the interaction mechanism between recycled plastic aggregates and lime matrix in composite mortars was investigated by means of thermal, morphological and Fourier Transform Infrared Spectroscopy (FTIR) analyses. In order to assess the fire behavior of the composite mortars, a cone calorimeter method was adopted. The plastic aggregate, mainly made of polyolefin and polyethylene terephthalate, is obtained from an industrial waste, through a process that provides a plasticization and densification by extrusion of plastic waste. Several composite mortars were prepared by replacing silica powder with 10%, 15% and 20% of recycled aggregate. Experimental results attest that, even if the filler was not chemically modified, there is a good chemical interaction between the plastic aggregate and mortar, involving a reduction of the negative effects on physical and functional properties of the mortar composites, such as thermal degradation and fire resistance. In fact all the specimens showed a scarce sensitivity to flashover, and can be classified as low risk materials.

The Fabrication and Properties Characterization of Wood‐Based Flame Retardant Composites

Wood‐based flame retardant composites were fabricated based on vacuum‐pressure impregnating method after high intensive microwave pretreatment. The effects of ammonium polyphosphate (APP) and modified nano‐zinc borate (nZB) addition on flame‐retardation and smoke‐suppression properties of wood were investigated by cone calorimeter method (CONE) and thermogravimetric analysis (TGA). The results show that the heat release rate (HRR), peak heat release rate (pk‐HRR), and total heat release (THR) of APP‐treated woods decreased greatly with increasing concentration of APP. However, mean yield of CO (Mean COY) of APP‐treated wood was much higher (3.5 times) than that of untreated wood. Compared with wood treated with APP at a concentration of 15%, the total smoke product (TSP), Mean COY, and pk‐HRR decreased by 78.4%, 71.43%, and 31.23%, when wood was treated with APP and nZB (both concentrations were at 15%). APP and nZB have synergistic effects of flame‐retardation and smoke‐suppression. Nano‐zinc borate combined with APP would be used in wood‐based composites to efficiently retard flame, reduce fire intensity, and decrease noxious (CO)/smoke release.

Review on Domestic and International Flammability Test Methods of Textile

Domestic and international testing methods of flammability property of textile, such as oxygen index method, vertical test method, 45 degree test method, horizontal test method and cone calorimeter method, were analyzed via comparing the principles, as well as their requirements of different acts and standards. To comprehensively evaluate the burning behavior of textiles, appropriate combination of methods should be chosen according to the practical application.

INVESTIGATION INTO THE INFLUENCE OF FLAME RETARDANT ADDITIVES ON SOME FIRE PROPERTIES OF POLYESTER MATERIALS APPLYING SMALL-SCALE TESTING TECHNIQUES

In order to investigate the impact of some inorganic additive flame retardants on the selected fire properties of the materials based on polyester resin Polimal 1033 APy, small-scale fire testing techniques have been used. Seven samples have been studied: unmodified PES, PES modified with MoO3 (7, 14 and 21 wt%) and PES modified with Sb2O3 (7, 14 and 21 wt%). The following flammable properties of materials have been determined: the heat of combustion (HOC), the ignition temperature of volatile thermal decomposition products (Tig), self-ignition temperature and oxygen index. A cone calorimeter method has been used for determining heat release rate (HRR), mass loss, specific extinction area (SEA) and other combustion parameters. The toxicological analysis of combustion products has been conducted. Based on the obtained results, the following conclusions have been made: (1) MoO3 and Sb2O3 added to the studied material change its flammable properties and fire parameters. It can be indicated by higher HOC, higher Tig and self-ignition temperature, as well as by lower HRR and SEA. Modified materials become safer in terms of fire hazard. (2) A significant reduction in HRRmax of approx. 40% in the content of 7 wt% has been observed. The lowest HRRmaxof approximately 300 kW/m2 and 450 kW/m2 have been obtained for 21 wt% in a range of 200–600 s at 30 kW/m2 and 100–400 s at 50 kW/m2 respectively. Except for a sample containing 7 wt% of Sb2O3, a clear local reduction in HRR (from 50 to 150 kW/m2), in case of all modified samples has been noticed. (3) Sb2O3 has a greater impact on the thermostability of the studied materials compared to MoO3 in all cases of heat flux density and additive concentrations. The effectiveness of Sb2O3, as a flame retardant is the most evident at 21 wt%.

Effect of modifiers on the flammability and physical properties of polyamide 6

Studies on the influence of selected modifiers (flame retardant, antioxidant, nanofiller) on the ignition, combustion and mechanical properties of polyamide 6 (PA 6) have been presented. The following methods were used: melt flow index (Table 2), oxygen index (Table 2), flammability UL-94 test (Table 2), thermogravimetric analysis (Fig. 2, Table 2) and strength characteristics in the static tensile test (Table 4). The smoke formation and heat release rate, the flammability of the material as well as the smoke density and toxicity of the volatile gas products released during the decomposition of the studied materials were determined using the cone calorimeter method under 35 kW/m2 heat flux conditions (Fig. 3, Table 3). It was found that the simultaneous use of three modifiers: 16 wt. % Exolite, 0.5 wt. % Irganox and 5 wt. % amine modified montmorillonite was most advantageous in terms of improving the fire safety of the materials.