Screening tests for fire safety of composites for marine applications

Abstract

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 costeffective 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 Â 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

Cone calorimeter testing of S2 glass reinforced polymer composites

“…The only measurement that increased in value with increasing S-2 glass content was the time to ignition, which went to longer times (delayed ignition) as the fiberglass content was increased in the epoxy composites. In general, these trends fit with those observed elsewhere in that as fiber content is increased, heat release decreases [24][25][26][27][28].…”

Fire protective performance of intumescent paint and ablative elastomer used for high pressure hydrogen composite cylinder

“…Thermogravimetric Analysis TGA, Differential Thermal Analysis DTA, or Differential Scanning Analysis DSC) [3][4][5][6][7] but also in small ones (i.e. ISO 5660 cone calorimeter) [8][9][10][11][12][13][14][15][16][17][18][19]. The last draws a wide attention in recent studies because of the better assessment of material behaviors in real fire scenarios.…”

“…The last draws a wide attention in recent studies because of the better assessment of material behaviors in real fire scenarios. Several reaction-to-fire properties of fiber-reinforced epoxy resin composites have been measured such as: time-to-ignition, heat release rate (HRR), amount and rate of mass loss, density and specific extinction area of smoke, gaseous emissions as well as limit oxygen index (LOI) [8][9][10][11][12][13][14][15][16][17][18][19]. It is found that different parameters as external heat flux, composite properties (nature of fiber, fiber content and fiber arrangement within composite, sample thickness) and fire environment condition, can have an influence on the thermal properties of composite.…”

Fire Safety Regulations

“…Despite the higher fire risk with naval vessels, many navies do not have clearly defined fire safety regulations. Some navies are considering adopting the IMO code for high-speed craft to their surface vessels, while other navies -most notably the United States Navy (USN)have established their own regulations to meet the unique operating conditions of warships and submarines [4,[16][17][18][19].…”

“…The USN has established two guiding principles for the use of composite materials in their vessels: (i) the material itself must not be the fire source and (ii) the flammability resistance of the material must be sufficient to allow the crew to respond to the primary fire source [4,[17][18][19][20]. Currently there is no fire safety standard applied to US naval ships, although several criteria have been set to reduce the hazard.…”