The effect of surface coatings on fire growth over composite materials in a corner configuration

Structural composites are vulnerable to fire in two respects: (1) their res in content may ignite and enable the spread of flames over the surface of t he structure; (2) the resin may degrade from the heat of a localized fire e xposure thus weakening the composite structure. The present study focuses m ainly on the first issue, in particular, on the ability of various commerci al coatings to prevent flame spread The second issue is examined briefly by applying thermocouples to the back surface of test specimens. Four commerc ial coatings have been tested over an unretarded vinyl ester/glass composit e. In addition an uncoated phenolic/glass composite and a polyester/glass c omposite coated with a fire retarded resin were tested. In all cases the co nfiguration was a 3.3 m high corner with a 53 cm square propane gas burner at its base, operated at 250 kW as the fire exposure. The results show that , with the proper choice of coating and coating thickness, fire growth can be suppressed quite effectively. Two of the coatings, applied at a substant ial thickness, mere reasonably effective at slowing the penetration of heat to the back of the composite panels. The other coatings, much thinner in a pplication, were notably less effective at slowing heat penetration. Publis hed by Elsevier Science Ltd.