Flame Resistant Fabric Treatments
Flame and thermal resistant fibers and fabrics can generally be divided into two groups: those that are inherently flame resistant, such as Nomex, and those that achieve flame resistance through special FR treatments, such as Cotton or Cotton Blends.
Nomex does not require any FR treatment because it is an inherently flame resistant material.Nomex garments will cost more initially, however the FR protection will not wash out and the life of the garment is much longer.
Cotton fabrics that are treated with flame retardant chemicals make them flame-resistant.
Cotton Fabrics are not normally considered protective, but will become so after having the FR chemical treatment. The durability of the treatment can vary from very limited to life of the garment.
AMMONIA CURE AND HEAT CURE
Cotton or Cotton blend fabrics are made flame-resistant by application of a flame retardant. This finish can be either a phosphonium salt precondensate polymerized with gaseous ammonia (THPOH-NH3), or a heat-cured dialkylphosphonamide. These processes bind the flame retardant to cotton fiber FR for durability. Either process has little effect on fabric hand and performance.
LIFE OF THE GARMENT
There are several variables that contribute to the life of a garment. Some fabrics are inherently flame resistant, such as Nomex, and those that achieve flame resistance through special “FR treatments”, such as Cotton or Cotton Blends.
Care instructions should be followed to ensure the full FR life of the garment, any improper laundering may shorten the FR life of the garment. Remember Nomex does not require any FR treatment, as it is an inherently flame resistant material. Nomex garments will cost more initially, however, because the FR protection will not wash out so the “life of the garment” is considerably longer.
These are not performance guarantees or even averages, just observations of real world performance.
“The above information is meant only as a guide, always consult the manufacturer of any FR garment to get better results on your product” commented the president of Grupo Denim Salomón Juan Marcos Villarreal.