인도네시아 주요 조림수종의 연소특성

역사마을인 한국의 하회 양동 마을은 볏짚지붕으로 된 초가집으로 구성되어 있고 일본의 역사마을인 시라가와고 또한 억새 지붕의 초가집이 존재하고 있다. 지붕재료의 연소특성은 역사마을에서 화재안전 확보를 위하여 중요하다. 본 연구에서는 착화시간(TTI), 유효연소열(Effective Heat of Combustion, EHC), 열방출율(Heat Release Rate, HRR), 총열방출율(Total Heat Release, THR), 질량손실율(Mass Loss Rate, MLR) 등을 콘 칼로리미터(ISO 5660-1)를 이용하여 측정하여 화재위험성을 평가하였다. 역사마을의 건물과 구조의 화재특성을 예측하는데 볏짚과 억새의 연소 데이터베이스가 이용될 수 있다. 연구결과, 초가지붕의 두 재료 중에서 억새가 볏짚보다 열적 위험성이 높은 것으로 나타났다. 또한 초가집 전체 연소시 최소 약 5.68 m 반경 이내의 초가집은 화재확산 가능성이 있는 것으로 평가되었다. Hahoe Village and Yangdong Village in Korea have straw-roofed houses and Shirakawa-go in Japan has silver grass-roofed houses. Combustion characteristics of these roof materials need to be identified in order to enhance fire safety in historical villages. This study used cone calorimeter (ISO 5660-1) and Flammability tester to measure combustion characteristics of thatched-roof materials to analysis hazard assessment in two historical villages. It also analyzed Time to Ignition (TTI), Effective Heat of Combustion (EHC), Heat Release Rate (HRR), Total Heat Release (THR), Mass Loss Rate (MLR) and ignition temperature. Database on combustion characteristics of straw (Oryza sativa) and silver grass (Miscanthus sinensis var. purpurascens) will be used to predict fire property of buildings and structures in historical villages. From the result, combustion data shown that Miscanthus sinensis var. purpurascens has high value than Oryza sativa for fire danger. Straw-roofed houses can be spread where is located within radius 5.68 m from straw-roofed house fires.

The degree of ageing, the combustion kinetic performance and the change law of the combustion characteristics of ancient pine were experimentally investigated using thermogravimetric analysis, calorimetry experiments, component analysis experiments and gas chromatography-mass spectrometry analysis. The results show that the hemicellulose, cellulose, lignin and resin contents of the ancient pine decreased by 4.78%, 3.87%, 1.39% and 0.63%, respectively. The volatile content of the ancient pine decreased by 7.37%, while the ash content increased by 5.02%. The terpenes in the ancient pine were almost decomposed, and the calorific value of the ancient pine decreased by 21.54%. The ignition point of ancient pine was 19.83°C lower than that of the fresh pine. The activation energy and heat of the pre-charring stage of the combustion of the ancient pine were 1.37 times and 0.51 times those of the fresh pine, respectively. In contrast, the activation energy and heat of the charring stage of the combustion of the ancient pine were 0.66 times and 1.2 times those of the fresh pine, respectively. The ignition time and peak time of the ancient pine were shorter, and the heat release rate, smoke production rate, specific extinction area and CO production rate were higher than those of fresh pine.

ABSTRACTA halogen‐free flame retardant system consisting of ammonium polyphosphate (APP) as an acid source, blowing agent, pentaerythritol (PER) as a carbonific agent and zinc oxide (ZnO) as a synergistic agent, was used in this work to enhance flame retardancy of phenolic foams. ZnO was incorporated into flame retardant formulation at different concentrations to investigate the flammability of flame retardant composite phenolic foams (FRCPFs). The synergistic effects of ZnO on FRCPFs were evaluated by limited oxygen index (LOI), thermogravimetric analysis (TGA), cone calorimeter tests, and images of residues. Results showed that the flame retardant significantly increased the LOI of FRCPFs. Compared with PF, heat release rate (HRR), total heat release (THR), effective heat of combustion (EHC), production or yield of carbon monoxide (COP or COY) and Oxygen consumption (O2C) of FRCPFs all remarkably decreased. However specific extinction area (SEA) and total smoke release (TSR) significantly increased, which agreed with the gas‐phase flame retardancy mechanism of the flame retardant system. The results indicated that FRCPFs have excellent fire‐retardant performance and less smoke release. And the bending and compression strength were decreased gradually with the increase of ZnO. The comprehensive properties of FRCPFs were better when the amount of ZnO was 1∼1.5%. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42730.

The high solid resol phenolic resin was prepared via step polymerization of formaldehyde, paraformaldehyde, and phenol using sodium hydroxide and calcium oxide as catalysts, and employed to prepare the phenolic foams (PFs) by the introduction of retardant additives including eco-friendly halogen-free flame retardants (ammonium polyphosphate), char-forming agents (pentaerythritol), and synergists (zinc oxide, molybdenum trioxide, cuprous chloride, and stannous chloride). The effects of these additives on flame retardancy, heat resistance, and fire properties of flame-retardant composite phenolic foams (FRCPFs) were evaluated by limiting oxygen index (LOI) tests, thermogravimetric analyzer, and cone calorimeter tests. It was found that the flame retardan significantly increased the LOIs of FRCPFs. Compared with PF, heat release rate, total heat release, effective heat of combustion, production or yield of carbon monoxide (COP or COY), and Oxygen consumption (O2C) of FRCPFs all remarkably decreased. However specific extinction area and total smoke release significantly increased, which agreed with the gas-phase mechanism of the flame-retardant system. The results indicate that FRCPFs have excellent fire-retardant performance and less smoke release. APP/PER/ZnO is shown to be better flame-retardant system for PFs.

Evaluating the flammability of wood-based panels and gypsum particleboard using a cone calorimeter

Influence of kaolinite/carbon black hybridization on combustion and thermal decomposition behaviors of NR composites

Two-scale tests, microscale and bench scale, are conducted to analyze the flammability of a flexible polyurethane foam. Microscale tests include simultaneous thermal analysis coupled to Fourier transform infrared spectroscopy, and microscale combustion calorimeter (MCC). Evolved gas components, heat release rate per unit mass, total heat release, derived heat release capacity, and minimum ignition temperature are obtained. Bench scale tests are performed on cone calorimeter. Peak heat release rate per unit area, effective heat of combustion, minimum incident heat flux for ignition, and total heat release per unit area of different incident heat fluxes are obtained. FO-category of the PU foam is estimated by multiple discriminant function analysis based on the results of cone calorimeter test. The relationship between the two-scale tests is analyzed. The minimum ignition temperatures derived from multi heating rate MCC tests are used to predict the time to ignition and compared with the results from cone calorimeter tests. This PU foam is evaluated as a high fire hazard polymer having low heat release capacity, low ignition temperature, and short ignition time.

The flame resistance properties of expandable polystyrene foams coated with a cheap and effective barrier layer

In order to study the influence of natural wood thickness on the flammability and fire performance, an experimental studies of fire parameters under external constant heat flux by piloted ignition of wood timber with different thicknesses (8, 10, 13, 15 mm) were conducted using cone calorimeter approach, by testing procedure prescribed in accordance with international organization for standardization. These parameters include: ignitibility, heat release rate, effective heat of combustion, total heat release, mass loss rate, smoke specific extinction area, and the yield of carbon monoxide. Four species of wood timber, namely pine, maple, oak, and walnut, were exposed horizontally under external heat flux 50 kW/m2. Thermal degradation effects of various species were observed. The obtainable data will be reported to develop a distinct national building code in Jordan and to select the suitable materials for designing of fire safety in buildings of different uses. A good compatible agreement between calculated and experimented results has been obtained. The results indicated that total heat release rate increase with increase thickness of specimen. It is observed that, the time to ignition is very small (around 12 seconds) for all species whatever the thickness is. Heat release rate for the different types of specimens with different thicknesses have been presented. Results show as the thickness of oak specimen increased: 8 mm, 10 mm, 13 mm and 15 mm, the corresponding mass loss depletions are 43%, 34%, 25%, and 21%, respectively.

Certain polymers, such as polyvinylidene fluoride (PVDF), polyimide (PI), and poly (phthalazinone ether sulfone ketone) (PPESK), are commonly used separator materials in batteries. However, during the thermal runaway (TR) processing of batteries, significant heat is released by the combustion of the polymer separator. Therefore, analysis of the fire behaviors of polymer separator materials will facilitate a more comprehensive quantitative evaluation of battery thermal risk. This paper investigated the combustion properties of three types of polymers, namely, PVDF, PI, and PPESK, as potential separator materials by cone calorimetry and thermogravimetry (TG). A series of characteristic parameters, including ignition time (TTI), heat release rate (HRR), smoke production rate (SPR), and total heat release (THR), were evaluated for three polymers and blends (PI/PVDF, PPESK/PVDF) under an external heat flux of 45 or 60 kW/m2, respectively. The combustion characteristics and fire hazards of the three polymers and corresponding mixtures were analyzed through the comparative analysis of experimental data and phenomena. Under 60 kW/m2, the HRR curves of all polymers presented two peaks, while PI/PVDF and PPESK/PVDF mixtures exhibited one obvious peak. Moreover, the peak HRR (pHRR) for the mixed polymers was higher, indicating a relatively higher fire risk. However, in the application scenario, the mixed state represents the main polymer form as the active separator materials in batteries. The results showed that the specific coupling behaviors were related primarily to the component type. This work will help evaluate the fire risk of polymeric separator materials based on the combustion characteristics to predict the safety of mixtures in batteries and develop new methods for fire suppression.

The NiMo/Mg(OH)2 (NMM) hybrid as an efficient flame retardancy and smoke suppression composite for polypropylene (PP) was synthesized through NiMo co‐precipitation on the surface of Mg(OH)2 (MH) hexagonal nanosheets. Compared to PP/MH, PP/NMM exhibited excellent smoke suppressing and flame retardancy on the heat release rate, total heat release, smoke production rate, total smoke production, CO production rate and total CO production with the same loading. The reduced hazard of PP/NMM was mainly attributed to the high physical barrier effect of compact char residues on heat, smoke and combustible gas. The mechanism study indicated that multiwalled carbon nanotubes (MWCNTs) generated from the catalytic carbonization of PP by the NiMo compound could play the role of “rebar” to strengthen the char residues, avoid the generation of cracks and form highly compact char layer. Furthermore, MgO could facilitate the production of MWCNTs through changing the pyrolysis process of PP and increasing the reaction time between pyrolysis gas and NiMo compound. Hence, the new NiMo/MH catalyst hybrid may explore the potential for solving the tough problem of the flammability and heavy smoke of the polyolefins system.

This study focuses on the increased risk of high heat release and asphyxiation (toxic gas poisoning) in the event of a fire involving polyurethane (PU)- and MDF-based building materials, which are commonly used in buildings. Among them, polyurethane (PU) building materials are very commonly used in buildings, except in Europe and some other countries, due to their excellent thermal insulation performance. Still, problems of short-term heat release and the spread of toxic gases in the event of a fire continue to occur. To overcome these problems, researchers are actively working on introducing various flame retardants into building materials. Therefore, in this study, we produced a laboratory-sized (500 mm × 500 mm) plate-like flame-retardant board that can be utilized as a building material with a lower heat release rate and a lower toxicity index. The material was made by mixing expanded graphite and ceramic binder as flame retardants in a material that is formulated based on the cellulose of waste paper, replacing the existing building materials with a hot-press method. According to the ISO-5660-1 test on the heat release rate of the plate-like flame-retardant board, the Total Heat Release (THR) value was 2.9 (MJ/m2) for 10 min, showing an effect of reducing the THR value by 36.3 (MJ/m2) compared to the THR value of 39.2 (MJ/m2) of the specimen made using only paper. In addition, the toxicity index of the flame-retardant board was checked through the NES (Naval Engineering Standards)-713 test. As a result, the test specimen showed a toxicity index of 0.7, which is 2.4 lower than the toxicity index of 3.1 of MDF, which is utilized as a conventional building material. Based on the results of this study, the cellulose fire-retardant board showed the effect of reducing the heat release rate and toxicity index of building materials in a building fire, which reduces the risk of rapid heat spread and smoke toxicity. This has the potential to improve the evacuation time (A-SET) of evacuees in fires. It is also important to show that recycling waste paper and utilizing it as the main material for building materials can be an alternative in terms of sustainable development.

Transparent wood is a modern bio-renewable material with great potential for both science and industrial applications. However, the fire hazard of transparent wood is still almost unexplored. This study aims to investigate the impact of pristine basswood modification to epoxy-based transparent wood on the fire hazard and to train neural networks for the prediction of heat release rate from mass loss rate of pristine basswood, epoxy-based transparent wood, and epoxy resin. Transparent wood was prepared by lignin modification in pristine small-leaved basswood (Tilia cordata Mill.) and subsequent vacuum infiltration by epoxy resin. The fire hazard of the samples was determined by the cone calorimeter at four heat fluxes of 20–50 kW m−2. The fire hazard of investigated materials was compared based on the critical heat flux, ignition temperature, heat release rate, effective heat of combustion and time to flashover. Transparent wood showed higher resistance to ignition (higher critical heat flux and ignition temperature) than pristine wood. However, other parameters (heat release rate and effective heat of combustion) were higher (worse) and the time to flashover was lower (worse) for transparent wood than for pristine wood. Trained neural networks for predicting heat release rate from the mass loss rate of wood (both pristine and transparent) and epoxy resin showed coefficients of determination from 0.70 to 0.92. Trained neural networks with a coefficient of determinations above 0.90 are usable for low-cost heat release rate measurements in both science and industrial applications.

Preparation of modified epoxy resin with high hydrophobicity, low dielectric constant, toughness, and flame retardant by epoxy-functionalized siloxanes

In this paper, pilot-ignited high pressure dual-fuel (HPDF) combustion of a natural gas jet is investigated on a fundamental basis by applying two separate single-hole injectors to a rapid compression expansion machine (RCEM). A Shadowgraphy system is used for optical observations, and the combustion progress is assessed in terms of heat release rates. The experiments focus on the combined influence of injection timing and geometrical jet arrangement on the jet interaction and the impact on the combustion process. In a first step, the operational range for successful pilot self-ignition and transition to natural gas jet combustion is determined, and the restricting phenomena are identified by analyzing the shadowgraph images. Within this range, the combustion process is assessed by evaluation of ignition delays and heat release rates. Strong interaction is found to delay or even prohibit pilot ignition, while it facilitates a fast and stable onset of the gas jet combustion. Furthermore, it is shown that the heat release rate is governed by the time of ignition with respect to the start of natural gas injection — as this parameter defines the level of premixing. Evaluation of the time of gas jet ignition within the operability map can therefore directly link a certain spatial and temporal interaction to the resulting heat release characteristics. It is finally shown that controlling the heat release rate through injection timing variation is limited for a certain angle between the two jets.