CCME, University of Newcastle upon Tyne Composites in Fire September, 2003 WELCOME Introduction to basic ideas of composites in fire WELCOME Introduction to basic ideas of composites in fire

CCME, University of Newcastle upon Tyne Composites in Fire September, 2003 FIRE REACTION The response of the material, especially in the early stages of a fire, and its interactions with the environment. Can be further subdivided into: progress of the fire human survivability. These can be regarded as characteristics of the material and can, quite often be determined from relatively small samples. Many properties (for instance, time to ignition and surface spread of flame) are influenced by the material at the surface of the product. The overall composition contributes to average heat release.

CCME, University of Newcastle upon Tyne Composites in Fire September, 2003 FIRE RESISTANCE the ability of the structure to retain functionality during a fire, the ability of a physical barrier such as a wall, bulkhead or protective coating to limit heat flux and prevent damage to material remote from the fire

CCME, University of Newcastle upon Tyne Composites in Fire September, 2003 Properties and tests Pool fire tests Burner tests Furnace tests Jet-fire tests FIRE RESISTANCE Smoke generation Toxicity index Human survivability Oxygen index Combustibility Time-to-ignition Surface spread of flame Peak heat release Average heat release Single burning item test Start-up and progress of fire FIRE REACTION

CCME, University of Newcastle upon Tyne Composites in Fire September, 2003 Polymeric matrices are flammable Fire requires: Fuel Oxygen Heat source

CCME, University of Newcastle upon Tyne Composites in Fire September, 2003 Fuel Combustion occurs mainly in the gaseous phase Heat O2O2O2O2 Smoke Combustion products Flame

CCME, University of Newcastle upon Tyne Composites in Fire September, 2003 Fuel Combustion requires: Heat O2O2O2O2 Smoke Combustion products gaseous fuelgaseous fuel diffusiondiffusion

CCME, University of Newcastle upon Tyne Composites in Fire September, 2003 Solid Polymer Volatiles + Char Heat + Combustion products Heat O2O2O2O2 Polymer combustion

CCME, University of Newcastle upon Tyne Composites in Fire September, 2003 Solid Polymer Volatiles + Char Heat + Combustion products Heat O2O2O2O2 Polymer combustion Effect of char formation?

CCME, University of Newcastle upon Tyne Composites in Fire September, 2003 CH 2 Phenolic resin (or resin with high aromatic content) Char Char Char formation

CCME, University of Newcastle upon Tyne Composites in Fire September, 2003 Solid Polymer Volatiles + Char Heat + Combustion products Heat O2O2O2O2 Polymer combustion Suppress combustion?

CCME, University of Newcastle upon Tyne Composites in Fire September, 2003 ADVANTAGE: Considerable reduction in ignitability and surface spread of flame DISADVANTAGE: Only of real use when the polymer itself is the main fuel source. When there is another fuel source, the polymer will burn. Halogens produce increased smoke and toxicity when the polymer does burn. NEVERTHELESS: Halogenated resins are still the mainstay of the industry Halogenated systems

CCME, University of Newcastle upon Tyne Composites in Fire September, 2003 Solid Polymer Volatiles + Char Heat + Combustion products Heat O2O2O2O2 Polymer combustion Prevent heat from getting to polymer?

CCME, University of Newcastle upon Tyne Composites in Fire September, 2003 Thermal insulation (OK if its refractory, i.e. rockwool, kaowool, Structogard etc.) Thick laminate effect Surface intumescents (thick or thin films) Surface engineering - intumescent veils, layers Internal intumescents ATH Preventing heat from reaching polymer

CCME, University of Newcastle upon Tyne Composites in Fire September, 2003Undamagedlaminate Laminate with decomposingresinVolatiles Behaviour of laminates: the thickness effect In some circumstances the composite itself can protect from fire

CCME, University of Newcastle upon Tyne Composites in Fire September, 2003 In conclusion, this brief introduction summarises the various avenues that are currently open to protect composite structures from fire, and to optimise their fire reaction properties.