Flame retardant are chemicals added to thermoplastics to minimize the risk of a fire starting in case of contact with a heat source or an electrical fault. In case of ignition, the flame retardant will slow down combustion and often prevent the fire from spreading to other items. Therefore flame retardant thermoplastics will interfere with the potential fire hazard by resisting ignition and delaying or preventing its propagation by extinguishing flames.
Flame retardant thermoplastics have various mechanisms which are;
Gas phase; the additives decompose and suppress the supply of oxygen
Solid phase; the additives generate an isolative char layer which act as a barrier for oxygen and heat
Cooling; the additives release water in order to cool the surface and extinguish flames.
Developing and formulating flame retardant thermoplastics compounds requires great expertise and know-how. Following parameters should be taken into consideration;
Combustibility
Ignitability
Flame spread
Heat release
Smoke development
Fire gas toxicity