Facts on Flammability

Slide 24 of 37

One of the frustrations in predicting performance is that the composite performance is rarely equal to the sum of the performance of individual components. As we discussed a moment ago, the behavior of melting fabrics on an FPF filling is generally much different than the behavior of the fabric on its own. Charring fabrics also produce unexpected results not found in component testing. A charring fabric or inter-liner over a melting filling material can produce a cavity under the char layer which continues to burn and propagate because the heat of combustion is retained and reflected back to the interior.

The same filling material used under a melting fabric or one that produces a thin fragile char layer will not continue to burn because the heat from burning can escape.

In the British Standard tests it was found that some combinations of PVC fabrics and polyester fabrics with FPF containing large amounts of melamine failed the test requirements, while other much less flame retarded systems passed.

Such examples prove again that component test results by themselves should not be used as the absolute criterion for approving the use of composites assembled from components that individually pass combustibility requirements.