Flame retardants for Polyester

The three possible approaches to flame-retardant polyester-additives to the polymer melt; flame-retardant copolymers and topical finishes- have all been used commercially to produce flame-retardant polyester textiles. All the methods employ phosphorous- or bromine-containing compounds as the active flame retardant. The most useful flame-retardant finishes for polyester was a bromine containing phosphate ester called Tris removed from marketplace because it was considered to be dangerously carcinogen. One current commercial flame retardant for polyester is a mixture of cyclic phosphate/phosphonates used in a pad-dry-heat process. Another approach to durable flame retardant finishes for polyester is the use of highly brominated chemical as topical finishes. Polyester fabrics when burned exhibit a melt-drip behaviour. Since the fabric melts away from the flame, some polyester fabric constructions can actually pass vertical flame tests without any flame-retardant treatment.