Toward halogen-free flame resistant polyethylene extrusion coated paper facings

Abstract

Wire and cable coverings are potentially a major cause of fire in buildings and other installations. As they need to breach fire walls and are frequently located in vertical ducting, they have significant potential to increase the fire hazard. It is therefore important to understand the ignition and burning characteristics of cables by developing a model capable of predicting their burning behaviour for a range of scenarios. The fire performance of electrical cables is usually dominated by the fire performance of the sheathing materials. The complexity of the problem increases when cable sheathing incorporates fire retardants. One-dimensional pyrolysis models have been constructed for cable sheathing materials, based on milligram-scale and bench-scale test data by comparing the performance of three different software tools (ThermaKin, Comsol Multiphysics and FDS, version 6.0.1).Thermogravimetric analysis and differential scanning calorimetry were conducted on powdered cable coatings to determine the thermal degradation mechanism, the enthalpy of decomposition reactions, and the heat capacities of all apparent species. The emissivity and the in-depth absorption coefficient were determined using reflectance and transmittance measurements, with dispersive and non-dispersive spectrometers and integrating spheres.Bench-scale tests were conducted with a mass loss calorimeter flushed with nitrogen on samples in a horizontal orientation, for comparison with the pyrolysis model of non-flaming decomposition at an external heat flux of 50 kW m -2 . The parameters determined through analysis of the milligram-scale data were used to construct a pyrolysis model that predicted the total mass loss from calorimeter tests in anaerobic conditions. A condensed phase pyrolysis model that accurately predicts in-depth temperature profiles of a solid fuel, and the mass flux of volatiles evolved during degradation of the fuel, is an essential component of a comprehensive fire model, which when coupled to a computational fluid dynamics code can be used to predict the burning processes in a fire scenario. Pyrolysis models vary considerably in complexity based on the assumptions incorporated into the development of the model.

Radiation-grafting of flame retardants on flax fabrics – A comparison between different flame retardant structures

“…Brominated FRs act as flame inhibitors in gaseous phase. Recent works have shown that other classes of FR can act as flame inhibitor, namely azoalkanes and derivatives (Aubert et al, 2011a(Aubert et al, , b, 2012Pawelec et al, 2012Pawelec et al, , 2015Tirri et al, 2014), disulfides (Pawelec et al, 2014) and sulfenamides (Tirri et al, 2016). They were found to be effective at very low content (typically 0.5 wt%) especially for polyolefins and polystyrene, alone or in synergy with various FRs (brominated FR, alumina trihydrate).…”

Tough Bioplastics from Babassu Oil-Based Acrylic Monomer, Hemicellulose Xylan, and Carnauba Wax

“…In addition to structural engineering employment, polyethylene is widely employed in packaging applications [ 58 , 59 ]. Specifically, LDPE is often used to coat paper as a moisture barrier [ 60 , 61 ]. To this end, we compared the water barrier properties of natural kraft paper covered with LDPE and the paper impregnated with CW and covered with PBBM-X/CW (40%).…”

Dual Fire Retardant Action: The Combined Gas and Condensed Phase Effects of Azo-Modified NiZnAl Layered Double Hydroxide on Intumescent Polypropylene

“…Wileń and colleagues have synthesized a series of azo-based FRs such as azos (R−NN−R) and/or triazenes (R−NN−N−R), which achieved excellent fire retardancy in a PP system 33,34 and a PE system. 35 Additionally, incorporation of azobenzene groups in a copolyester can significantly increase the amount of residue and thermo-oxidative stability due to its high-temperature self-cross-linking characteristics. 36 Moreover, the azo compounds possess good UV absorption ability.…”

“…Recently, some articles reported that when LDHs were modified by organic anions such as SDBS, DBS, SPDP, CEPPA, and SIEPDP, they greatly increased the interlayer distance and thus enhanced the dispersion properties and the fire-retardant properties of the composites. Wilén and colleagues have synthesized a series of azo-based FRs such as azos (R–NN–R) and/or triazenes (R–NN–N–R), which achieved excellent fire retardancy in a PP system , and a PE system . Additionally, incorporation of azobenzene groups in a copolyester can significantly increase the amount of residue and thermo-oxidative stability due to its high-temperature self-cross-linking characteristics .…”