Fire Retardant Chemicals Research Articles

Artificial-weathering test requirements for fire-retardant-treated wood to reproduce optimal chemical retention and moisture conditions

Despite the increasing outdoor use of fire-retardant-treated wood, methods for predicting its service life remain poorly established. With the aim of establishing a method to predict chemical losses from fire-retardant-treated (FRT) wood caused by humid atmospheres and rain outdoors, this study examined the preferable conditions for artificial-weathering tests and demonstrated the acceleration coefficients in these tests (i.e., the ratio of equivalent time to reach the same retention of chemicals in artificial weathering and outdoors) based on the EN927-6 standard. To determine the moisture absorption and desorption levels of FRT exposed to outdoor conditions, an outdoor exposure experiment was conducted. The moisture content was higher in the FRT wood than in untreated wood, regardless of the type of coating, and ranged between 11% (in March) and 50% (in September) of the untreated wood’s weight. EN927-6 artificial weathering tests were performed on two groups of specimens with initial moisture contents of 0% and 25%. Retention rates of fire-retardant chemicals after a 2520-h test were compared with those retrieved from 4-year outdoor exposure reported elsewhere. Comparison of these two experiments demonstrated that the acceleration coefficients were 4.1–11.3 in the case of specimens with 0% initial moisture content and 5.1–11.4 in the case of specimens with 25% initial moisture content. The higher initial moisture content produced a more uniform acceleration coefficient. Nevertheless, larger acceleration coefficients were derived from specimens with penetrating or semi-film-forming coatings in both cases. The relationships between the uniformity of this acceleration coefficient and the initial moisture content are discussed from the moisture absorption experiment under constant temperature and humidity and under condensation conditions.

Effect of Borax-Boric Acid Treatment on Fire Resistance, Thermal Stability, Acoustic, and Mechanical Properties of Mycelium Bio Composites

Mycelium biocomposite materials have been established as a sustainable alternative to polystyrene in single use applications like packaging. However only little investigations are done on improving their resistance to fire and heat, which can find use in newer applications. This paper focuses on the development and characterization of a mycelium-based sawdust-coir pith biocomposite material treated with a combination of fire-retardant compounds (borax and boric acid). The outcomes of fire resistance tests, such as flammability, flame penetration and rate of burning demonstrated a significant improvement in values with respect to untreated samples. However, samples having 30% boron compounds by weight in it exhibited the best fire resistance properties. The thermal analysis of treated samples indicated that the presence of fire-retardant chemicals has not significantly affected their thermal stability. The glass transition temperature (Tg) of treated mycelium composite material was found to be 212.75 °C against a value of 207.78 °C for untreated samples. The fire retardant treated mycelium composite samples having 30% boron by weight in it, exhibited an average sound absorption coefficient of 0.38 compared with a sound absorption coefficient of 0.29 for polyurethane foam. The prepared mycelium biocomposite has a self-extinguishing nature and exceptional fire resistance capabilities with an LOI value of 50%. The mechanical testing revealed that the presence of fire-retardant chemicals has significantly improved the flexural properties. However, only a marginal increase was visible in the compression strength of mycelium biocomposites.

Surface free energy, wettability and bonding of plywood after fire-retardant treatment with various chemicals

Plywood usage has been increasing recently in the building and furniture industry due to its outstanding surface and resistance properties. Although it has many advantages, the flammability of plywood needs to be improved with fire-retardant chemicals. However, these chemicals which improve panels against burning can be differently influenced many properties of panels. This study aimed to investigate the surface roughness, wettability, and surface free energy of the veneers treated with some fire-retardant chemicals and to determine the changes in the mechanical properties of plywood. The beech, poplar, alder, and pine veneers were used as wood species whilst zinc borate, borax, monoammonium phosphate, and ammonium sulfate were used as fire-retardant chemicals in this study. The surface roughness and contact angle measurements were performed to determine the surface properties of veneers, and then the surface free energy values were calculated. The bonding and bending strength of the plywood panels produced from these veneers were determined according to the relevant standards. As a result of the study, the surface free energy values of veneers with lower contact angles and smoother surfaces were found to be higher. It was also determined that the bonding strength values of plywood panels produced from veneers with high surface energies were also high. Generally, the untreated veneers had higher surface free energy values than the treated veneers. Among the fire-retardant chemicals, zinc borate caused the highest surface free energy values in the beech and alder veneers while borax exhibited the highest values in the poplar and pine veneers.

“Old” and “new” contaminants and their management: learning from the past, looking to the future

Within the 50 year lifetime of the Society for Environmental Geochemistry and Health (SEGH), we have seen a number of contaminants transfer from being the wonder chemical of their day through to becoming current contaminants of concern. This is also true for a variety of emerging contaminants such as plastic microbeads, pharmaceutical residues, and fire retardant chemicals, amongst others. This thought piece discusses the risk associated with a range of these emerging contaminants, their global nature, how existing models and frameworks can be applied to deal with their impacts, and research and management gaps and challenges.Graphic

Influence of fire retardant and pyrogenic carbon on microscale changes in soil nitrogen and phosphorus

During wildfire season in the western US, fire retardant chemicals are dropped from aircraft in an effort to control the spread of fire. Fire retardant dropped on sites that are not actively burning results in exceptionally high soil nitrogen (N) and phosphorus (P) “fertilization” effect on wildland soils impacting terrestrial and aquatic ecosystems. Herein, we used microdialysis to evaluate the short-term spatiotemporal dynamics of soil inorganic N and ortho-P fluxes in response to wood pyrogenic carbon (PyC) on soils receiving fire retardant (Phos-Chek) in a 28-d column experiment. Retardant additions to soil induced dramatic increases in soil inorganic N and ortho-P flux rates. The addition of wood PyC to soils with retardant significantly and immediately reduced ortho-P flux rates at multiple depths (1, 5, and 10 cm) and reduced NH4+ flux rates at 10 cm while retaining flux rates at 1 and 5 cm. These effects were observed throughout the course of the experiment and were more pronounced towards the end of the experiment. By d-28, PyC significantly reduced the NH4+, NO3−, and ortho-P accumulation on ionic resins at soil column bottoms by 50%, 52%, and 43%, respectively. The application of wood PyC may be effective at buffering excess nutrient fluxes from fire retardant and reduce short-term nutrient leaching in unburnt forest soils exposed to fire retardant.

Yangın Geciktirici Kimyasallarla Emprenye Edilmiş Kontrplakların Retensiyon Miktarları ve Mekanik Dirençlerinin Yapay Sinir Ağları ile Tahmin Edilmesi

The treatment with fire retardant chemicals is the most effective process to protect wood and wood based products from fire is. Therefore, use of fire retardant chemicals has been increased. However, the fire retardant chemicals have an effect on other physical, mechanical and some technological properties of the materials treated with them. In this study, firstly, the retention level prediction model was developed with the artificial neural network (ANN) to examine the effects of wood species and concentration aqueous solution on the retention levels of veneers. Then, the effects of wood species, concentration aqueous solution and retention level on the mechanical properties of plywood were investigated with the mechanical strength prediction model developed with ANN. The prediction models with the best performance were determined by statistical and graphical comparisons. It has been observed that ANN models yielded very satisfactory results with acceptable deviations. As a result, the findings of this study could be employed effectively into the forest products industry to reduce time, energy and cost for empirical investigations.

Effect of Boron and Phosphorus Compounds on Fire and Technological Properties of Oriented Strandboard

Effects of various fire retardant chemicals on fire and technological properties of laboratory made oriented strandboards (OSBs) were investigated. Aspen chips were used in the production of OSB panels. An exterior liquid phenol formaldehyde resin with 47 percent solid content was used as adhesive. There was no addition of any hardener and filling materials into resin in the OSB manufacturing. Boron compounds such as borax and boric acid, and phospate compounds such as monoammonium phosphate and diammonium phospahate were used as fire retardant chemicals in the OSB panels. An exterior liquid phenol formaldehyde resin was used as adhesive. The chemicals in powder form were added into the resin blender at contents of 2%, 4%, and 6% based on oven-dry wood weight. The OSB panels containing borax had the highest thickness swelling, followed by the panels containing boric acid, monoammonium phospahate, and diammonium phosphate, respectively. Increasing the content of these chemicals in the OSB resulted in greater thickness swelling. For the mechanical properties, the chemicals can be used up to oven dry particle weight of 6% in the panels at humid and dry conditions because of the fact that they met the standard values of mechanical properties given in TS EN 300 for types of OSB/3 (exterior type. Fire resistance of the panels was improved with increased chemical content in the panels.

Producing Fire Retardant Cotton Fabric Using Chicken Eggshell

Cotton has poor fire retardance characteristics. As a result, the textile material is not recommended in areas of fire risks though it has high comfort factor that make preferable for wearing purpose; therefore, imparting fire retardance is must to cotton. This research focuses on producing fire retardant cotton fabric using chicken eggshell to replace synthetic fire-retardant chemicals. Chicken eggshell contains fire-retardant mineral such as calcium carbonate, phosphorous, nitrous, potassium and zinc. Imparting fire retardance using synthetic chemicals has many limitations; toxicity, environmental hazards, non-biodegradable, non-renewable source and cost. On the other side chicken eggshell being bio-product has not any side effects since it occurs in nature abundantly. In most cases the chicken eggshell is removed after usage or hatching causing a big environmental pollution in appearance as well as in odour. Conversion of such wastes to treasure has a dual benefit in preventing cotton from burning extension and using the eggshell wastes for valuable treatment process. Treated fabric using chicken eggshell showed low flammability than untreated. In addition, the treated fabric formed ash and char, whereas untreated fabric produced only ash and got totally burn. The fire propagations were 40 and 1.4 mm per second for untreated and treated fabrics respectively.

The Reaction to Fire of Some Chemicals Treated Pine Wood Product Surface

Wooden materials have been extensively used for furniture, outdoor and indoor cladding, buildings, terrace, fence, garden furniture and interior decoration and to decorate the roofline of houses. However, wood which is used outdoors or in areas exposed to moisture needs to be protected against wood-destroying organisms and to be shielded from water, marine pests, fungi, fire and weather conditions. Untreated wood materials have no resistance to the spread of fire and many buildings which constructed from wood based materials needs to fire resistance. It is possible that the wooden material ensures very durable and resistant against physical effects by surface applications such as wood preservative paint and acrylic resin-based varnish. The application of fire retardant chemicals can also provide to satisfy regulatory requirements for wood products. In this study, titanium dioxide and antimony trioxide were applied on pine (Pinus sylvestris L.) solid wood material to determine durability of reaction to fire using by oxygen index test technique (ASTM D 2863-6) and real fire test. These chemicals were added to the wood preservative paint which is a commercial product as concentrations of 2%, 5% and 10% for titanium dioxide and 2% and 5% for antimony trioxide. The effects on colour change of their surfaces, brightness and surface roughness measurements, water absorption and thickness swelling of this wood material were also carried out. The results obtained were analysed statistically and compared with the related standards. Addition of these chemicals to used wood preservative paint had a positive impact on the fire properties of the pine wooden surface.

The effect of diammonium phosphate and sodium silicate on the adhesion and fire properties of birch veneer

Abstract In built environments the combustibility of wood is a great concern, which limits the use of wood as a building material due to legislation. The reaction-to-fire properties of wood can be altered with the use of fire-retardant chemicals, and most of the commonly used fire retardants already have a long history of use. However, only limited information is available on the impact of different fire retardants on the adhesion properties of wood. Additionally, comparative studies between chemicals from different groups of fire retardants is scarce. The objective of this study was to investigate and compare the effects of two commonly used fire retardants, sodium silicate (SS) and diammonium phosphate (DAP), on veneer properties, the focus being especially on thermal behavior and adhesion. Thermal properties and combustibility were studied using thermogravimetric analysis (TGA), flame test and calorimetry. Glue bond strength was analyzed with an automated bonding evaluation system (ABES) and the leaching of chemicals was determined according to EN84. Additionally, the surface characteristics of modified veneers were imaged with scanning electron microscopy (SEM). Results revealed notable differences in the thermal properties of SS and DAP, with DAP having better fire-retardant performance in all thermal testing. SS also affected thermal properties and combustibility of modified veneers, but the effect was only moderate compared to DAP. Neither SS or DAP had any significant resistance against leaching but ABES testing showed a notable increase in the glue bond strength of DAP modified veneers.

Twenty-first century technology of combating wildfire

Wildfire causes havoc and serious destruction of forest resources and wildlife. It also causes occasionally serious damages to human lives and properties. Current technology of fighting wildfire employs fire retardant chemicals, which pollute the environment seriously, and damages both wild and aquatic lives. Based on the new novel technology, it is possible that in the near future the industrial emissions that pollute the environments and cause health problems would be completely captured in frozen solid forms of emissions products. One of these is the frozen carbon dioxide, which is known as dry ice, which would be available than in hundreds of millions of tons in any country. Cost analysis shows that the power and cement industries would significantly benefit by selling the dry ice captured using the technology, just at $0.07 per kg. The present paper discusses the new technology of applying dry ice that would thus be abundantly available in fighting a wildfire. The paper discusses how the new technology would be by far superior to current technology that employs fire retardant chemicals in terms of environmental protection and the cost-effectiveness over the current technology.

RESEARCH DEVELOPMENT FIRE BLANKET

Research development fire blanket is a follow-up study from previous researchers.This research is intended to obtain fire blankets from best fabric, using best chemicals, which are widely available on market and very easy to get on market, so that general public can easily obtain fabric and chemicals used for development this fire blanket in community.This study uses ten types of fabric, three types of fire retardant chemicals, and three types of preservative chemicals, so that fire blanket fabric according to its function can inhibit spread of fire / extinguish fire in event of fire, and not quickly damaged / torn /decay eaten by insects.The fabric of fire blanket is included in class 2, which is somewhat resistant to fire /rather non-flammable, under class 1 which is completely non-flammable, namely fabric two sides blue with mixture 6 C and mixture 2 C. Fabricantifire from Korea with mixture 2 C. Fabric jeans, corduroy, two sides red, and body rock, all with mixture 6 C.Other fabrics include grade 3, which is resistant to fire under grade 2.

Investigation of some surface properties and thermogravimetric analysis of veneer sheets treated with fire retardants

This study investigated the effects of different fire retardant chemicals on surface and thermal properties of veneer sheets. Beech (Fagus orientalis), alder (Alnus glutinosa), poplar (Populus deltoides) and scots pine (Pinus sylvestris) were chosen as wood species and zinc borate, borax, monoammonium phosphate and ammonium sulfate were chosen as fire retardant chemicals. The samples were impregnated by using the immersion method. Some surface properties such as colour measurements and surface roughness of the veneer sheets were conducted according to CIE L*a*b* system. Some thermal properties such as thermal conductivity of the veneer sheets were conducted according to standard and weight loss after combustion was determined by thermogravimetric analysis. Conforming to the results from the study, it was found that fire retardant chemicals increased the thermal conductivity and surface roughness of veneer sheets. Also, thermogravimetric analysis experiments showed that all of the fire retardant chemicals decreased the loss in weights.

The effects of liquid nitrogen treatment on the some physical and mechanical properties of scots pine and oriental spruce wood

The wood materials widely used from wood construction sector, urban furniture and interior design to furniture sector are renewable resource. Wood has some disadvantages regarding durability to combustion and biological factors. To increase service life especially in urban furniture are coated and/or impregnated against to fire and biological factors. Thus, the wood materials used in construction sector should be treated with fire-retardant chemicals. In this study; Scots pine and Oriental spruce wood materials were exposed to liquid nitrogen for 30 minutes before impregnated with Firetex by using pressure-vacuum method. According to the results, amount of retention in Oriental spruce and Scots pine samples have been increased with liquid nitrogen treatment. Additionally, it was seen that the liquid nitrogen operation had not significant adverse effect on the mechanical properties. Therefore, the liquid nitrogen treatment can apply effectively as a method to improve the impregnability of the wood.

Effect of Various Fire Retardant Chemicals in Different Concentrations on Formaldehyde Emission of Plywood

Ozet Calismanin amaci: Emprenyeli levhalar, kontrplak piyasasinda genis bir yer edinmelerine ragmen, bazi ahsap koruyucularla emprenye islemi, yapisma kusurlari, emprenye sonrasi kimyasal atiklarindan dolayi olusan cevre kirliligi gibi bazi problemlere sebep oldugu bilinmektedir. Ahsap esasli levhalardan aciga cikan formaldehit, ic mekanlarin hava kalitesinde etkili olan baska bir problemdir. Bu calismada, yangin geciktirici kimyasallar ile emprenye edilmis kontrplak levhalarinin formaldehit emisyonu miktarlarinin arastirilmasi amaclanmistir. Calisma alani: Bu calisma, Trabzon’daki Karadeniz Teknik Universitesi Orman Endustri Muhendisligi Bolumu Pilot tesisinde yapilmistir. Materyal ve Yontem: Kavak, kizilagac ve saricam ( Pinus sylvestris L.) kaplamalar, kontrplak icin kullanilmistir. Cinko borat, monoamonyum fosfat ve amonyum sulfat, yangin geciktirici olarak kullanilmistir. Kaplama levhalari, %5, 7 ve 10 olmak uzere uc farkli cozelti konsantrasyonu secilmis ve daldirma yontemi kullanilarak emprenye edilmistir. Kontrplak levhalarinin formaldehit emisyonu miktarlari, DIN EN 717-3 standardinda belirlenen sise yontemine gore belirlenmistir. Sonuclar: Cinko borat ile emprenye edilmis kaplamalardan uretilen kontrplak levhalardan aciga cikan formaldehit kontrol gruplarindan daha yuksek bulunmustur ve emisyon degerlerinin, konsantrasyon arttikca arttigi belirlenmistir. En dusuk formaldehit emisyon degerleri, monoamonyum fosfat ve amonyum sulfat ile emprenye edilmis levhalardan elde edilmistir ve emisyon degerlerinin, konsantrasyon arttikca azaldigi belirlenmistir. Arastirma vurgulari: Yuksek direnc ozelliklerinin aranmadigi bazi kullanim yerlerinde, formaldehit emisyonunu azaltmak icin yangin geciktirici kimyasallarla (monoamonyum fosfat ve amonyum sulfat) emprenye edilen kaplamalardan uretilen kontrplak levhalari kullanilabilir.

Fire Properties of Pinus densiflora Utilizing Fire-retardant Chemicals Based on Borate and Phosphorus (II) – Thermal and Gas Emission Characteristics

The pyrolysis characteristics of untreated pine and fire retardant-treated pine (Pinus densiflora) were measured by using thermogravimetric analysis according to the ASTM E1131-08 (2012) regulation. Fourier transform infrared spectroscopy was used to monitor changes in chemical groups of fire-retardant treated specimens before and after the combustion test. In addition, the microstructures of the untreated specimen and the fire-retardant treated specimen after cone calorimeter testing were determined by scanning electron microscopy. Combustion gas toxicity was evaluated according to the test method described in Naval Engineering Standard 713 (1990). The emitted combustion gases of all specimens were carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxide (NOX), and acrylonitrile. The thermal decomposition rate was reduced by about one-third that of the fire-retardant treated specimen compared to the reduction rate of the untreated specimen. These results are useful for guiding the safe utilization of fire retardant-treated wood and wood-based materials for building applications.

Investigation of the effect of some fire retardant chemicals and mineral materials used in surface coating on combustion performance of particleboard

The combustion resistance was investigated for dolomite, melamine (MEL), and ammonium polyphosphate used in the surface coating of particleboard. The surface coating materials consisted of a mixture of dolomite, melamine dust, ammonium polyphosphate, calcite, and water. The ratio of dolomite, melamine dust, and ammonium polyphosphate in the mixture was determined to be 10% based on the amount of calcite. The resulting mixture was applied to the surface of the particleboard at a thickness of 0.20 mm. Combustion tests were carried out according to ASTM E 69 standard. As a function of weight loss, the temperature values, amount of oxygen, amount of carbon dioxide, and nitrogen oxides of the test samples were determined. The results showed that the coating increased the combustion resistance of particleboard. Samples containing a 70% dolomite, 25% melamine dust, and 5% ammonium polyphosphate mixture or 100% dolomite produced the best results. The use of ammonium polyphosphate and dolomite positively affected combustion resistance.

Fire Properties of Pinus densiflora Utilizing Fire-retardant Chemicals based on Borated and Phosphorus (I) – Combustion Characteristics

The combustion and thermal characteristics of fire retardant-treated pine (Pinus densiflora) were evaluated according to the KS F ISO 5660-1 (2003) standard, using a cone calorimeter. The specimens were treated with fire-retardant chemical compounds using pressure-impregnation equipment to reliably impregnate the compounds inside the wood. The heat release rate value of the fire retardant-treated wood specimens showed that the heat release time was delayed. A reduction of the total heat release value can indicate that fire was prevented from igniting in the materials during combustion. The microstructures of natural specimen and treated fire-retardant chemical compounds specimen were determined by scanning electron microscopy. It also confirmed that the pressure-impregnation processing method was effective in comparison to the other treatment methods.

Performance evaluation of plywood prepared from fire retardant treated veneers

Treatment of plywood with fire retardant chemicals requires pressure treating the plywood with chemicals for sufficient period to get desired retention. However, the pressure treatment requires installation of treatment cylinders of the size of plywood to be treated which might be a limiting factor. In the present study, five different fire retardant compositions were prepared for the treatment of veneers and plywood were prepared from the treated veneers. The prepared plywoods samples were tested for glue shear strength, flame penetration, rate of burning and flammability tests. It was found that the composition containing phosphoric acid was the best performer in fire retardance without compromising on the glue shear strength.

UN test O.1 errors in quantifying the behavior of solid oxidizers

The results of the UN test O.1 for oxidizing solids are shown to be incorrect when specimens contain certain inertant additives, illustrated for the case of oxidizers in the ammonium nitrate fertilizer family. Test results for three different AN-based products containing inertants show that two of the three (including calcium ammonium nitrate, CAN, a long-known safer alternative to AN) would be misranked with the O.1 test. An analogy between the heat release rate of substances containing fire retardant (FR) chemicals is established and several ways by which FR behavior can be achieved are demonstrated. It is shown that the O.1 test implicitly adopts only one model of inertant action, and that chemicals which rely on a differing mode of inertant action are liable to be incorrectly treated. It is further shown that the physical basis of the O.1 test—an intimate mixture of finely-comminuted fuel and oxidizer—misrepresents the most common type of accidents involving oxidizers, and that such test results do not correspond to scenarios of a less extreme nature. The new O.3 test improves the analysis method, but does not resolve the problem of excessive commingling of fuel into oxidizer. It is recommended that the intermediate-scale arrangement used by the Bureau of Explosives be adopted for further development and standardization, in preference to the O.1 or O.3 test arrangements.