24 Jul Thermoplastics are critical
Thermoplastics are critical because as the name says they are “plastics that can thermally be changed”. Apply heat to a thermoplastic and it will start to change its physical form. Apply sufficient heat and it will turn from solid, to liquid, to gas.
If the changes in physical form happen in the right temperature range then they can more easily become available as fuel to feed a fire. If the fire in burning releases sufficient heat to maintain a sufficient rate of melting and then gas formation then it can sustain itself – however 3 things are needed for fire.
see Fire Triangle
There are also circumstances when a molten polymer can flow like a liquid and contribute significantly to the spread of fire and it is often a requirement that any such potential in a textile is recognised and assed in testing.