Synergistic Fire Performance Between Metal or Metal Filled Organic Coatings and Engineering Plastics

1993 ◽  
Vol 11 (5) ◽  
pp. 371-393 ◽  
Author(s):  
Ramazan Benrashid ◽  
Gordon L. Nelson

Metal filled organic and EMI coatings affect the fire performance properties of engineering plastics. Zinc arc spray, zinc/epoxy, and zinc borate/epoxy coatings on modified-polyphenylene oxide (m-PPO) are particu larly effective. The results from non-flaming NBS smoke chamber tests show a dramatic reduction in smoke for zinc and zinc borate coatings, whereas a ZnO coating did not show the same effect. Heat release data (Radiant Panel) for these samples show lower Q values for zinc, zinc borate coatings compared to m-PPO, epoxy coated m-PPO and ZnO epoxy coated m-PPO. The Fs values for zinc and zinc borate coatings are low compared to a m-PPO control and ZnO coated m-PPO. Polycarbonate structural foam sheet was coated with epoxy coatings filled with zinc, zinc borate, or ZnO. NBS Smoke Chamber data in the non-flaming mode for zinc or ZnO coatings do not show an improvement in smoke produc tion, but a zinc borate epoxy coating does have a reductive effect on smoke. Ra diant Panel Q was low for all coated samples compared to a control. Fs values also were low for coated samples. From OSU heat release data the zinc borate/epoxy coating shows a low heat release rate and the zinc/epoxy coating a much delayed heat release rate. Data for smoke (2 min) was low for coated samples compared to a control, but for smoke (peak) only zinc borate demon strated the potential for significant smoke reduction.

2018 ◽  
Vol 53 (12) ◽  
pp. 1705-1715 ◽  
Author(s):  
Yousof M Ghazzawi ◽  
Andres F Osorio ◽  
Michael T Heitzmann

The fire performance of polycarbonate resin and the role of glass fibre reinforcement in altering the fire performance was investigated. Three different fibre weaves with comparable surface density, plain, twill, and unidirectional glass fabrics, were used as reinforcements. E-glass fabrics were solution-impregnated with polycarbonate/dichloromethyl, laid up, and compression-moulded to consolidate the glass fibre reinforced polycarbonate composite. Cone calorimetry tests with an incident radiant flux of 35 kW/m2 were used to investigate the fire properties of polycarbonate resin and its composites. Results showed that glass fibre reinforcement improves polycarbonate performance by delaying its ignition, decreasing its heat release rate, and lowering the mass loss rate. The three fibre weave types exhibited similar time to ignition. However, unidirectional fibre had a 35% lower peak heat release rate followed when compared to plain and twill weave fibres.


2019 ◽  
Vol 37 (3) ◽  
pp. 257-272 ◽  
Author(s):  
Chenkai Zhu ◽  
Jingjing Li ◽  
Mandy Clement ◽  
Xiaosu Yi ◽  
Chris Rudd ◽  
...  

This study investigated the effect of intumescent mats (M1 and M2) with different compositions on the post-fire performance of carbon fibre reinforced composites. The sandwich structure was designed for composites where M1 (carbon fibre reinforced composite-M1) or M2 (carbon fibre reinforced composite-M2) mats were covered on the composite surface. A significant reduction in the peak heat release rate and total heat release was observed from the cone calorimetric data, and carbon fibre reinforced composite-M1 showed the lowest value of 148 kW/m2 and 29 MJ/m2 for peak heat release rate and total heat release, respectively. In addition, a minor influence on mechanical properties was observed due to the variation of composite thickness and resin volume in the composite. The post-fire properties of composite were characterised, and the M1 mat presented better retention of flexural strength and modulus. The feasibility of two-layer model was confirmed to predict the post-fire performance of composites and reduce the reliance on the large amounts of empirical data.


Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2998 ◽  
Author(s):  
Giuseppina Barra ◽  
Liberata Guadagno ◽  
Luigi Vertuccio ◽  
Bartolome Simonet ◽  
Bricio Santos ◽  
...  

Different industrial mixing methods and some of their combinations ((1) ultrasound; (2) mechanical stirring; (3) by roller machine; (4) by gears machine; and (5) ultrasound radiation + high stirring) were investigated for incorporating multi-walled carbon nanotubes (MWCNT) into a resin based on an aeronautical epoxy precursor cured with diaminodiphenylsulfone (DDS). The effect of different parameters, ultrasound intensity, number of cycles, type of blade, and gear speed on the nanofiller dispersion were analyzed. The inclusion of the nanofiller in the resin causes a drastic increase in the viscosity, preventing the homogenization of the resin and a drastic increase in temperature in the zones closest to the ultrasound probe. To face these challenges, the application of high-speed agitation simultaneously with the application of ultrasonic radiation was applied. This allowed, on the one hand, a homogeneous dispersion, and on the other hand, an improvement of the dissipation of heat generated by ultrasonic radiation. The most efficient method was a combination of ultrasound radiation assisted by a high stirring method with the calendar, which was used for the preparation of a carbon fiber reinforced panel (CFRP). The manufactured panel was subjected to dynamic and vibroacoustic tests in order to characterize structural damping and sound transmission loss properties. Under both points of view, the new formulation demonstrated an improved efficiency with reference to a standard CFRP equivalent panel. In fact, for this panel, the estimated damping value was well above the average of the typical values representative of the carbon fiber laminates (generally less than 1%), and also a good vibroacoustic performance was detected as the nanotube based panel exhibited a higher sound transmission loss (STL) at low frequencies, in correspondence with the normal mode participation region. The manufactured panel was also characterized in terms of fire performance using a cone calorimeter and the results were compared to those obtained using a commercially available monocomponent RTM6 (Hexcel composites) epoxy aeronautic resin with the same process and the same fabric and lamination. Compared to the traditional RTM6 resin, the panel with the epoxy nanofilled resin exhibits a significant improvement in fire resistance properties both in terms of a delay in the ignition time and in terms of an increase in the thermal resistance of the material. Compared to the traditional panel, made in the same conditions as the RTM6 resin, the time of ignition of the nanotube-based panel increased by 31 seconds while for the same panel, the heat release rate at peak, the average heat release rate, and the total heat release decreased by 21.4%, 48.5%, and 15%, respectively. The improvement of the fire performance was attributed to the formation of a non-intumescent char due to the simultaneous presence of GPOSS and carbon nanotubes.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Xia He ◽  
Xianjun Li ◽  
Zhu Zhong ◽  
Yongli Yan ◽  
Qunying Mou ◽  
...  

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.


2017 ◽  
Vol 898 ◽  
pp. 2399-2404 ◽  
Author(s):  
Jin Mei Li ◽  
Jia Qing Zhang ◽  
Qiang Li ◽  
Zi Dong Guo

To evaluate the fire performance of the cable in service, the ignition time, heat release rate and insulation failure parameters of the accelerated thermal aging cable on stimulated fire condition were studied. The results show that, the extended ignition time and decreasing peak of heat release rate of the cable in the early stage of aging are the addictive including the lubricant, plasticizer and anti-oxygen. In the aggravating of thermal aging, labile materials with low heating value will be exhausted, while the thermal stability of insulation sheath material decreases, its corresponding ignition time will start to shorten and initial peak of heat release rate will start to rise. The insulation failure temperature of the cable is related with the decomposition temperature of insulation materials of the cable by heating. In each aging stage, the decomposition temperatures of insulation materials by heating are all lower than the insulation failure temperature of the cable for about 10°C. The reason for the insulation failure of the cable is that the ambient heat , gives rise to the decomposition by heating of internal insulation materials of the cable through sheath materials finally under the thermal transmission effect.


2013 ◽  
Vol 295-298 ◽  
pp. 2287-2293
Author(s):  
Huai Bing Zheng ◽  
Xu Jian Peng ◽  
Min Xia Zhang ◽  
Lin Ju

On condition that the heat release rate is 50kW•m-2, the volume of a gas velocity is 24 L•s-1, the combustibility of Pinus koraiensis、Pinus sylvestris var. mongolica、Picea koraiensis、Larix gmelinii in Heilongjiang Province were determined systematically through the use of the controlled atmosphere tapered calorimeter. Through the comparative analysis of the heat release rate and the smoke production rate and some orther burning parameters of the barks and the withered leaves, combine the moisture content of barks and withered leaves of each species, evaluate the fire resistance of this four coniferous species. The results shown: the heat release rate, HRR; total heat release, THR; specific extinction area and smoke produce rate are higher in the barks and withered leaves of Picea koraiensis but the fire performance index is low, these instructions that the fireproof performance is worse in Pinus sylvestris var. mongolica; each Picea koraiensis burning indexs of the Larix gmelinii is lower or the lowest, both the smoke production rate, SPR and the heat release rate, HRR are slow, the fire performance index is high. However, its absolute moisture content and relative moisture content is the highest, it’s flammble.So,we conclude its fire-resistance performance is higher, we could choose it as the fire-preventing priority screening tree species; the flammability of Pinus koraiensis and Pinus sylvestris var. mongolica between the above two species. the combustion characteristics of trees is the result of multiple factor joint, The difference between the different research results is resulted in the choice of the indexs, so it’s urgent need to establish a comprehensive and integrated evaluation index system.


2019 ◽  
Vol 37 (3) ◽  
pp. 273-300 ◽  
Author(s):  
Xi Cheng ◽  
Jianming Wu ◽  
Chenguang Yao ◽  
Guisheng Yang

Aluminum hypophosphite combined with melamine cyanurate and poly(phenylene oxide) was applied to flame retard TPE-S system (blends of SEBS and polyolefin). TPE-S containing 16 wt% aluminum hypophosphite, 20 wt% melamine cyanurate, and 10 wt% poly(phenylene oxide) pass a V-0 rating in the UL-94 test and its limiting oxygen index value is 28.2%. Zinc borate and magnesium hydroxide were added to modify the AHP/MCA/PPO formulation. Thermogravimetric–Fourier transform infrared analysis tests showed that aluminum hypophosphite and melaminecyanurate acted in gaseous phase while aluminum hypophosphite and poly(phenylene oxide) helped to form char residue. TPE-S/AHP/MCA/PPO significantly decreased the heat release rate (reduction in peak heat release rate from 2001 to 494 kW m−2). Scanning electron microscopy/energy dispersive spectrometry results demonstrated that zinc borate and magnesium hydroxide promoted to retain more P and O elements in residue. Zinc borate and magnesium hydroxide in AHP/MCA/PPO formulation enhanced the char formation and reduced gas evolution of TPE-S, thus deteriorating the combination between gaseous phase and condensed phase.


2018 ◽  
Vol 16 (1) ◽  
pp. 108-115 ◽  
Author(s):  
A.A. Hanna ◽  
M.A. Nour ◽  
E.R. Souaya ◽  
M.A. sherief ◽  
A.S. Abdelmoaty

AbstractFire performance of polypropylene (PP) containing different percentages of ammonium polyphosphate (APP) with montmorillonite (Mt) or treated montmorillonite (MtT) was carried out by using the cone calorimeter test (CCT). Different samples from ammonium polyphosphate and montmorillonite were mixed with 90% polypropylene. The characterization of the prepared samples indicates that there is incorporation between the components of the samples. Heat release rate (HRR), peak heat release rate (PHRR), average heat release rate (Av-HRR), and time to ignition (TTI) of the samples were obtained from the cone calorimeter test. Also, the fire performance index (FPI) and the fire growth rate (FIGRA) were calculated. The interpretation of the curves and the parameters results from the cone calorimeter test which indicates that the addition of montmorillonite to APP increases its action as a flame retardant for PP. Moreover, the samples contain acid treatment montmorillonite showed an increase in the efficiency of ammonium polyphosphate when used. This result may be due to an increase in the SiO2 content by acid treatment.


1994 ◽  
Vol 12 (5) ◽  
pp. 452-480
Author(s):  
Ramazan Benrashid ◽  
Gordon L. Nelson

Polycarbonate sheet installed as windows in a house in Newton, Massachusetts, was subjected to natural weathering for a period of 12 years. The surface of the sheet turned yellow. The coating material on the surface was peeled off, then the exposed layers of polycarbonate surface carefully removed. The DSC of the exposed surface showed multiple transitions compared to a con trol which showed only one Tg. TGA studies showed early weight loss for the ex posed polycarbonate compared to the control. Flammability studies including Oxygen Index, Radiant Panel, OSU Heat Release Rate Calorimetry and NBS Smoke Chamber showed an increase in the flammability of exposed sheet com pared to a 12 year aged control. Reasons for this increase in flammability are discussed.


2007 ◽  
Vol 334-335 ◽  
pp. 737-740
Author(s):  
Russel J. Varley ◽  
Andrew M. Groth ◽  
Kok Hoong Leong

This paper presents results of a study carried out to evaluate the effects of an organomodified nanoclay, either on its own or in combination with a polyimide, upon the fire performance of a commercially available nylon. The fire performance, as determined using cone calorimetry showed that up to 40% improvement in the peak heat release rate could be achieved at addition levels of only around 5wt% of nanoclay. The level of improvement was shown to be strongly dependent upon nanoscale dispersion with a more highly exfoliated morphology, as determined using transmission electron microscopy, which showed a greater reduction in the peak heat release rate compared to a more ordered intercalated structure. Investigation of the mechanism of fire retardancy showed that the reduction in the heat release rate is due to the nanoclay reinforcing the char layer which prevented combustible products from entering in to the gaseous phase. Generally, though, the time to ignition is unaffected by nanoclay additions. The addition of the polyimide to the nanoclay reinforced nylon was inconclusive showing little evidence of further improvements in fire performance.


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