Ignition resistance

Ignition accelerator Ignitioncup Ignitionpoint Ignition resistance... 

Fire test methods attempt to provide correct information on the fire contribution of a product by exposing a small sample to conditions expected in a fire scenario. Methods can be viewed in two ways the first entails the strategy of the fire test, ignition resistance or low flammabiUty once ignited the second addresses the test specimen, a sample representative of the product or a sample of a material that might be used in the product. Fire science has progressed markedly since the older test methods were developed and it is known that the basis for many of these tests is doubthil. Results from older tests must be used with great care. 

Figure 12.3 Clrromatogr-ams of an ignition-resistant high-impact polystyrene sample (a) Microcolumn SEC fi ace (b) capillary GC trace of peak x . Peak identification is as follows 1, ionol 2, benzophenone 3, styrene dimer 4, palmitic acid 5, stearic acid 6, styrene trimers 7, styrene trimer 8, styrene oligomer 9, Irganox 1076 and Irganox 168 10, styrene oligomer 11, nonabromodiphenyl oxide and 12, decabromodiphenyl oxide. Reprinted with permission from Ref. (12).

An example of a direct comparison of performance properties with and without added flame retardants for "New ignition resistant polycarbonate resins" is provided in a paper by workers at the Dow Chemical Company (32). The technology of the flame retardant additives is de scribed as including... 

Total additive loadings rarely exceed 1% of the finished resin. The criteria for ignition resistance are based on oxygen index and UL-94 ratings. The mode of action of the flame retardants is reported to be consistent with that of aromatic sulfonates as proposed by Webb (27). 

In 1978, the Home Office report (14) concerning the fire behaviour of new (i.e. post 1945) materials specifically criticised the fire performance of upholstered domestic furniture and recommended manufacturers to improve ignition resistance, to reduce flammability, and to reduce the rates of smoke and toxic gas generation. 

The principle of the 1988 Consumer Safety Regulations is that all filling materials and covering fabrics shall be ignition resistant against specified flames. An exception is made for specified types of fabric which may be used with a flame retarded interliner. 

In an ideal situation the parameters used to define furniture should be ignition resistance and the rate of generation of heat, smoke and toxic gases. Tests to do this with actual or mock-up full sized furniture are not yet available as final specifications but the Nordtest (28) and NBS furniture calorimeters (29) represent scientific methods while room/ corridor rigs, typically UK DOE PSA FR5 and 6 of 1976 (5) (6) were originally used but are less satisfactory from a scientific point of view. The Californian (30) and Boston tests (31) for public area furniture are essentially simple room tests and are similar in principle to DOE, PSA, FR5 and 6 although the latter do not have pass/fail criteria. Bench scale rate of heat release tests include the NBS cone (29) which, with a code of practice represent a possible alternative but the rate of burning of... 

Although the ignition resistance of upholstered furniture, mattresses and bed assemblies are specified by tests on the final composite specimen, filling materials and foams are additionally required to conform to the 1988 regulations (Table IX). 

Combining ignition resistant fabrics with combustion modified PU foam will significantly improve the fire performance of upholstered furniture and mattresses. 

Because of the lack of suitable standard rate of heat, smoke and toxic gas generation tests, the 1988 UK regulations are based on ignition resistance of individual materials. This contradicts the basic requirements for the fire testing of composites and of hazard related tests and as such it may be possible to develop materials which meet the requirements but which produce hazardous products. 

Standard Methods of Tests and Classification for Cigarette Ignition Resistance of Components of Upholstered Furniture 1989. 

Ignition Quality Tester (IQT), 12 422-423 Ignition resistant (IR) fiber blends, 13 385 Ignition-resistant applications, VDC copolymers in, 25 737 Ignition-resistant materials, 11 449-450 Ignition suppression, by silver, 22 640 Ignition temperatures, 10 871 21 840 of ethers, 10 579... 

In most commercial references to FR -PBT blends, what is really meant by FR is that the materials are ignition resistant - not impervious to fire. With limited heat sources, such as in the UL-94 test [52] or the glow wire test [53], the FR blends will resist ignition or self-extinguish a small flame. However, in a large fire, these resins will bum, usually with a smoky flame. 

Spalding, M. A., Nelb, R.G., Patterson, J., Youngson, C., and Zawisza, M. J., Processing Ignition-Resistant Polystyrene Resins In Injection Molding Machines, SPE ANTEC Tech. Papers, 47, 476 (2001)... 

Sturgis and coworkers (82) measured the relative surface ignition resistance of various pure hydrocarbons by a method based on deposit-induced ignition in a CFR... 

NUMBER OF DEPOSIT-INDUCED IGNITIONS Figure 2. Relative ignition resistance of hydrocarbons... 

Figure 4. Ignition resistance of gasoline blending stocks...

The effect of the addition of several aromatic amines on the surface-ignition resistance of an aviation gasoline has been determined by Male o6) 2% by weight of each of six... 

Figure 5. Ignition resistance of commercial premium gasolines...

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