Repeatability and reproducibility of fire tests for cigarette ignition of upholstered furniture composites

An analysis has been made to compare the repeatability and reproducibility of three tests for cigarette ignition of upholstered furniture composites: ASTM E1352, ASTM E1353 and NIST 851 mock-up. The first two of these tests are traditional methods designed to assess the potential of upholstered furniture components to being ignited by cigarettes while the last one, NIST 851 mock-up, is a new method designed to assess the propensity of cigarettes to ignite upholstered furniture composites. The traditional methods, ASTM E1352 and ASTM E1353 use a single cigarette for each determination and can be run in two ways: to obtain a numerical output of char length on the substrate (following the standard) or to obtain a pass/fail result for the substrate (practical use); the precision was analysed in both fashions. The new method, NIST 851 mock-up, uses 144 cigarettes for each determination (48 each on three substrate composites), and assesses the fraction of substrates that have been ignited (char length exceeding 10 mm), i.e. by a combination of pass/fail data. The analysis for actual char length was made according to ASTM E691 guidelines, while the analysis of the pass/fail was made according to a modification applicable to binary data. The precision of the test methods was as follows (in descending order): NIST 851>ASTM E1353 P/F>ASTM E1352 P/F>ASTM E1353>ASTM E1352 © 1998 John Wiley & Sons, Ltd.     

Flame spread properties of forest products. Comparison and validation of prescribed Australian and North American flame spread test methods

Nineteen forest products in sawn board and panel form (including three fire retardant treated) have been tested to AS1530.3—Test For Early Fire Hazard Properties of Materials and ASTM E84—Standard Test Method for Surface Burning Characteristics of Building Materials. These tests are used in the building codes to regulate the flame spread properties of all combustible building materials in Australia and interior finsihes in North America, respectively. A correlation was established between Time to Ignition (AS1530.3) and Flame Spread Index (ASTM E84) for the forest products that had not been fire retardant treated. Room fire testing of eight of the forest products validaded Time to Ignition (AS1530.3) and Flame Spread Index (ASTM E84) as reliable test criteria for regulating the use of combustible materials.     

Some factors influencing fire spread over room linings and in the ASTM E–84 tunnel test

An examination of the correlative relationship between room fire intensity (temperature) and flammability data for materials, ASTM E–84 flame ratings and energy release rate from calorimertry devices is presented for fire spread on lings. The results of the analysis show the significance of two modes of flame spread—wind-aided and opposed-flow spread. The factors important in these spread modes are considered from approximate solutions developed for turbulent flow. As the importance of energy release rate to flame spread in the tunnel test (E–84) and in upward or wind-aided spread is illustrated. The results suggest a possible reason why the ASTM E–84 and in upward or wind-aided spread is illustrated. The results suggest a possible reason why the ASTM E–84 ratings may not be applicable to the performance of low-density combustible linings in wall fires. In the analyses, flame radiation has not been considered. Also the interpretation of energy release rate data for difference scale and orientation effects has been ignored. These two factors must ultimately be addressed.     

Measurement of thermophysical properties of fire‐resistive and reactive materials. Urgent problems and solutions

The ASTM Standard Test Method E2584 ‘Standard Practice for Thermal Conductivity of Materials Using a Thermal Capacitance (Slug) Calorimeter’ was developed by National Institute of Standards and Technology to measure thermal conductivity of fire‐resistive and reactive materials during monotonic heating and cooling. The heating regime adopted in ASTM E2584 is very reasonable because change of materials' composition and structure during a fire can depend on kinetic factors and thermal story of the materials. The main problem in experimental measurements of thermophysical properties is the impossibility of using standard steady‐state methods during time‐dependent processes in materials accompanied by latent heat effect. Using standard transient methods, such as hot wire or laser flash methods, is also incorrect, because the transient measurement heat process can be started only after steady‐state temperature field is established in the sample, that is, at the time when the involved physical or chemical processes could be finished. The objectives of this paper are to review and to analyze scientific problems to be taken into account in the revised version of ASTM E2584 Standard. Examples of experimental results are presented for measurement of thermophysical properties during chemical and physical processes in solid materials, powders, metals, and ceramic materials; building materials during fire; and so on. Copyright © 2016 John Wiley & Sons, Ltd.     

The role of flame flux in opposed-flow flame spread

The flame spread process is driven by the net heat flux to the specimen surface, including the flux from the flame itself. This flame flux is important since it comprises a major part of the driving force causing flame fluxes were obtained. The values which are reported do not appear consistent and show more deviation among materials than would be anticipated. The most common fire test used for obtaining engineering data on flame spread (ASTM E 1321) also is not formulated in terms of flame flux as a driving force. This motivated an experimental programme, whereby six materials have been studied using the flame spread geometry of the ASTM E 1321 test, but with additional instrumentation for recording heat fluxes. The flame fluxes obtained experimentally in this study show much less variation among materials than the comparable data from the literature survey.     

Conversion of visual to instrumental measurement of yellowness

Yellowness is the result of a tendency of many materials (especially organic) to absorb more light in the blue end than in the rest of the visible spectrum. For approximately 100 years, yellowness of materials has been rated by visual comparisons with either standardized glasses or standardized solutions of reagent grade chemicals. Since 1942, paints, textiles, plastics and many other materials have been rated for yellowness by photoelectric measurements based on the spectral response characteristics of the normal human eye. Four of the long-established and widely used visual scales for yellowness are related herein to four of the newer and more precise photo-electric tristimulus scales. The four visual scales are Lovibond, Hazen, Gardner and FAC. The tristimulus scales are ASTM D1925, ASTM E313, Hunter b and CIELAB b^*. These interrelations between scales were actually developed more than 20 years ago by Ron Stillman of the AOCS, but his data were so voluminous that no opportunity for their publication was ever found.     

Evaluation of Fracture Toughness for Ceramic Materials by a Single-Edge-Precracked-Beam Method

As a substitute for the fatigue-cracked-beam method prescribed in ASTM E399 A2, a recently devised precracking method was applied to the evaluation of fracture toughness of ceramic materials. Straight-through precracks proved to be easily introduced into rectangular beams of several ceramic materials. This method gives K_ic values almost identical with those of the fatigue-cracked-beam method. The K_ic values are almost constant over wide ranges of the pop-in precrack length and the loading rate of the three-point bend test. The test can be easily performed even at elevated temperatures although its validity should be further examined.     

Fire-resistant coatings for roof/ceiling deck timbers

Laboratory tests demonstrated that the intumescence resulting from application of some proprietary flame-retardant paint and coating systems to timber planks could reduce char formation in the planks by as much as 70% during the first 30 min of exposure to ASTM E–19 fire conditions. Applications of these coating systems to the exposed surfaces of planks used in construction of heavy timber building assemblies should increase the fire resistance of these components by at least 30 min. This would represent a significant increase in the fire resistance of heavy timber roof systems and could extend the use of this type of construction system to many of the non-residential buildings for which building code authorities presently require fire resistance ratings greater than 1 h.     

A comparative study of combustibility and surface flammability of building materials

Results are presented of a project to evaluate the combustibility and surface flammability of building interior finish materials commonly used in Taiwan. The project was conducted at the Fire Laboratory of the Architecture and Building Research Institute in Taipei. Eighteen different wall-covering materials were tested according to Chinese National Standard (CNS) 6532, which is equivalent to Japanese Industry Standard (JIS) 1321, and according to ASTM E 1354-92 (Cone calorimeter). A comparison of test results is presented, and a qualitative relationship is developed between the performance in the two methods. The classification system for degrees of combustibility developed in Canada by Richardson and Brooks was hereby used to group materials based in performance in the ASTM test method. © 1997 John Wiley & Sons, Ltd.     

Metrology,documentary standards,and color specifications for fluorescent materials

Some aspects of the metrology of fluorescence are reviewed. ASTM Committee E-12 on Appearance has written two documentary standards on the instrumental measurement of fluorescent colors. Test Method E 1247 provides two procedures for detecting small amounts of fluorescence that might affect the measurement or use of nominally nonfluorescent materials. Practice E 991 deals with the measurement of specimens meant to be viewed under standard natural daylight, and that, therefore, must be illuminated by a good instrument daylight simulator. Two procedures are given for assessing the suitability of the simulator, and the required instrument geometry is specified. A future ASTM standard is under consideration that would describe methods for correcting the data obtained with another instrument source to the data that would have been obtained with standard daylight illumination. Two groups of standard specifications exist for fluorescent colors used for signaling or safety enhancement. One defines suitable chromaticities for both red and orange colors [among others], but ignores the fact that these colors cannot always be obtained with good lightfastness by use of existing pigments. the other group provides instead a red-orange specification for which specimens with good lightfastness can be obtained. the relative merits of the two groups are discussed.     

Screening tests for fire safety of composites for marine applications

Demands for reduced maintenance, reduced manning and reduced cost are resulting in the need for new and alternative materials for introduction in the fleet. The new materials in many cases tend to be non‐metallic and organic (combustible) materials. In order to maintain a minimum level of fire safety, the US Navy has set performance requirements for new materials in many applications. These include the use of composite materials in ships and submarines. Performance requirements for composites, in most cases, are based on full‐scale fire tests. The use of composites for structural applications in submarines is covered by MIL‐STD‐2031. The use of composites aboard US Navy ships for topside applications is now covered by Fire Safety testing criteria. The recommended fire performance criteria contain requirements for fire growth, smoke toxicity, visibility (ISO 9705), fire resistance and structural integrity under fire (UL 1709). When developing new composite systems, it is expensive to repeatedly conduct these typical full‐scale fire tests to determine the performance of the most recent design. Instead, more cost‐effective small‐scale testing is preferable to evaluate performance. To facilitate the introduction of new and modified fire tolerant materials/systems/designs, and to reduce the financial burden on small business, the US Navy has developed a low cost composite system fire screening protocol which offers the potential of predicting the full‐scale fire performance. Fire growth potential of new composite systems and designs can be screened by using small‐scale test data from cone calorimeter (ASTM E‐1354) and Lateral Ignition Flame spread Test (ASTM E‐1321) in conjunction with the Composite Fire Hazard Analysis Tool (CFHAT). The small‐scale burn‐through test (2×2 ft) was shown capable of screening fire resistance performance determined in furnace testing with a UL‐1709 fire curve. These screening techniques provide cost‐effective approaches for evaluating fire performance of new technologies, which in turn aids in the product development process. Full‐scale fire testing is still required before inclusion of products onboard US Navy submarines and surface ships. Published in 2002 by John Wiley & Sons, Ltd.     

Corrosion performance of conventional (ASTM A615) and low-alloy (ASTM A706) reinforcing bars embedded in concrete and exposed to chloride environments

Conventional reinforcing steel is used in the majority of reinforced concrete structures. In general, steel reinforcement meeting ASTM A615 specifications has been the predominant reinforcement used for these structures. Low-alloy reinforcing steel (ASTM A706) was developed and is being marketed to improve ductility and weldability deficiencies associated with the ASTM A615 reinforcement. Several State Highway Agencies have adopted the use of these low-alloy reinforcing steels. Limited research has been performed on the corrosion characteristics of the steel reinforcement meeting ASTM A706 specifications. This paper presents results from a laboratory study on the critical chloride threshold, macrocell corrosion rates, and mass loss testing for ASTM A706 and ASTM A615 reinforcing steels embedded in concrete and exposed to chloride solution. Results from this study indicate that ASTM A706 reinforcing steel exhibits lower critical chloride threshold levels and higher corrosion rates than ASTM A615 reinforcing steel when embedded in cementitious materials.     

Fracture toughness characterizations of compatibilized polyamide-6 (PA6)/poly(phenylene ether) (PPE) blends

Under the plane-strain condition, the material properties, K_IC and G_IC, of the blends, brittle or with small-scale yielding, increase with increasing elastomer content. To evaluate the critical J-integral for the ductile blends, several methods have been compared to understand the influence of elastomer content and different thicknesses using single-edge notch-bend specimens. For a given thickness, the fracture toughness increases with increasing elastomer content. Moveover, the slope of the R-curve becomes gradually steeper with increasing elastomer content and decreasing specimen thickness. J_IC values determined from ASTM E813-89 and modified ASTM E813-81 methods always give the highest and the lowest values, respectively. J_IC values determined from three other methods are comparable and can be employed to characterize the fracture toughness of the compatibilized PA6/PPE blends. It is noted that J_IC values determined from the modified ASTM E813-89 and the hysteresis energy methods are apparently independent of thickness. Therefore, these two methods may be considered as potential alternative techniques to evaluate the critical J-integral for toughened polymer blends.     

Study of thermal stability and ablation behavior of carbon/epoxy‐novolac composites

The use of carbon/epoxy‐novolac composites as advanced ablative materials for insulation of exit cone of solid‐propellant rocket nozzles are studied. In this article, three types of carbon fabrics are used and their composites are prepared by use of impregnation and hand lay‐up methods. To study the thermal stability and ablation behavior, these composites are tested by thermal tests such as thermogravimetric analysis (TGA) and oxyacetylene standard flame tests; the latter test is one of the most important standard tests of ablative materials. The test apparatus is made according to American standard, ASTM‐E‐285‐80, and over 33 polymeric composites and 3 steel specimens were carried out according to its standards. It is found that the composites that are made up of C‐9750 fabric (high‐strength carbon fabric) in comparison with steel and the other types of carbon fabric specimens have the highest thermal stability and the best ablation behavior. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2455–2461, 2003     

Fire performance of fire-retardant wood fiberboard ceiling tile

Wood fiberboard-based, cellulose ceiling tiles have been used for many years. While various fire-retardant technologies have been developed to reduce the surface flammability of these products to acceptable levels, questions of their suitability for use due to their intrinsic fuel value and the impact of attachment methods used on fire performance have been raised from time to time. This paper reviews the history of these products from a fire-performance perspective and presents materials property data on surface flamespread, thermal conductivity and ignition phenomena. In addition, large-scale room fire test results are presented including compartment tests conducted on a variety of assemblies (including those installed with mastic construction adhesives) according to ASTM E 603—Standard Guide for Room Fire Experiments.     

Mechanical properties of zirconia-based ceramics asfunctions of temperature

Commercially available ceramics, MgO–ZrO₂, CeO₂–ZrO₂, and an in-house fabricated zirconia-toughened mullite were examined in this study for use as a structural component in diesel engines. The fast fracture strengths of these materials were measured by loading ASTM C-1161-B specimens in four-point flexure at 30 MPa/s and at 20, 200, 400, 600, and 850 °C. The dynamic fatigue or slow crack growth susceptibility was assessed at 20 and 850 °C by combining the fast fracture strengths with strength data obtained by testing the same specimens in four-point flexure at 0.30 and 0.003 MPa/s stressing rates, as specified in the ASTM C 1368 standard. Fracture toughness was measured following the ASTM C-1421 standard and using chevron notch specimens in three-point flexure at room and elevated temperatures. The strength of the zirconia-toughened mullite was invariant to increases in the temperature and decreases in the loading rate, while the MgO–ZrO₂ and CeO₂–ZrO₂ materials exhibited strength degradation as temperatures increased and the loading rates decreased. Temperature was observed to have the greatest influence on facture toughness. As temperatures increased, the fracture toughness values dramatically decreased for all the materials examined in this study. Improvements in the fracture toughness are needed most for these ceramic materials in order to meet the structural requirements and to develop a more durable and reliable diesel engine component.     

Plane-strain fracture toughness of epoxies at different loading rates

The plane-strain fracture toughness of two common epoxy systems of different ductility were determined at different loading rates, according to ASTM E 399 for metallic materials. The ASTM standard was applicable, but underestimated slightly the specimen thickness required for K_Ic. K_Ic decreased with an increasing loading rate and with an increasing yield stress. The fracture surfaces were all very smooth as long as plane-strain conditions prevailed.     

热界面材料热导率和接触热阻的测试

热界面材料通常用于降低电子器件中固体界面的热阻。热界面材料的性质, 如热导率、界面材料与固体表面间的接触热阻, 对于电子器件的散热分析非常重要。然而, 这些参数通常难以获得。依据ASTM D-5470测试标准, 搭建了一个热界面测试系统。通过该系统测试了硅油和导热硅脂的热导率, 以及它们与固体基板间的接触热阻。经分析, 测试热导率和接触热阻的相对误差分别小于11.3%和41.3%。     

Evaluation of heat release rate equations used in standard test methods

A thorough review was recently conducted to verify the correctness of equations being used to calculate heat release rate in standard test methods. The review incorporated 17 different standard test methods from American Society of Testing and Materials (ASTM), National Fire Protection Association (NFPA), Uniform Building Code (UBC), California Technical Bulletin (CA TB), International Standards Organization (ISO), and British Standards (BS). The standard test methods reviewed were ASTM D5424, ASTM D5537, ASTM E1354, ASTM E1537, ASTM E1590, ASTM E1623, ASTM E1822, NFPA 264, NFPA 265, NFPA 266, NFPA 267, CA TB 129, CA TB 133, UBC 8-2, UBC 26-8, ISO 5660, BS 476. Through this review, incorrect equations were found in 12 of the 17 standards with a total of 22 incorrect equations overall. The following paper provides the correct heat release rate equations and a summary of the review. © 1998 John Wiley & Sons, Ltd.     

A new method for computing optimum weights for calculating CIE tristimulus values

Weighing tables are widely used for calculating CIE tristimulus values. In this article, a direct method for computing optimum weighing tables for any illuminant and observer combination is developed. A comprehensive set of 1‐nm reflectance functions based upon Munsell samples is used to test various methods. Four types of weighing tables are compared. They are ASTM E308 Tables 5 and 6, ASTM E2022, and new tables proposed by this study. The results clearly show that the newly developed optimum tables outperform the other three types of tables. The new method is simple and avoids the iterative process used by Venable and adopted by ASTM for some of its tables. It may be used for calculating weighing tables for any combination of illuminant and observer. A detailed procedure and a worked example are given in the article. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 91–103, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10229