Flame Retardant Masterbatches
Halogenated types
Non Halogenated types
They are incorporated in plastics to reduce the ease with which the plastics can be ignited and reduce the rate at which the plastics can burn once ignited.
Most of the thermoplastic catch fire and hence cannot be used in speciality applications such as components of aircrafts, building materials and sophisticated electronic equipments, etc. Hence, the use of flame retardants has become mandatory in some of the plastics component uses.
Fire is caused essentially by heat, fuel and oxygen. Chemical flame retardants work by limiting one or more of these elements, thus reducing the fire spread.
Broadly, flame retards are classified as :
Although halogenated types are more effective flame retardants, they have other adverse effect such as toxicity and higher smoke density. Hence, many a times antimony trioxide or alumina trihydrates are synergistically used with halogenated flame retardants to reduce smoke density and toxicity.
Masterbatches with a variety of combinations are available for different thermoplastics which can give flammability ratings of either 94 VO, 94 V1 or 94 V2 by flammability test devised by Underwriters Laboratory. Flame retardant additives in plastics are negatively influenced by carbon blacks, some pigments, calcium carbonate, antistatic agents and commoners such as vinyl acetate.