Flame-retardant finishes requirements

Nondurable Finishes. Flame-retardant finishes that are not durable to launderiag and bleaching are, ia general, relatively iaexpensive and efficient (23). In some cases, a mixture of two or more salts is more effective than either of the components alone. For example, an add-on of 60% borax (sodium tetraborate) is required to prevent fabric from burning, and boric acid is iaeffective as a flame retardant even at levels equal to the weight of the fabric. However, a mixture of seven parts borax and three parts boric acid imparts flame resistance to a fabric with as Utde as 6.5% add-on. 

Flame-retardant finishes provide textiles with an important performance characteristic. Protection of consumers from unsafe apparel is only one area where flame retardancy is needed. Firefighters and emergency personnel require protection from flames as they go about their duties. Floor coverings, upholstery and drapery also need protection, especially when used in public buildings. The military and the airline industry have multiple needs for flame-retardant textiles. 

The toxicity of some flame-retardant components and of their combustion gases is a particular concern for flame-retardant finishes, especially if based on halogens and several heavy metals. Therefore, aircraft textile equipment has to fulfil special requirements, for example, smoke density and toxicity tests. Toxicity problems include ... 

Flame retardant finish for technical wool fabrics. Within the technical textile sector, wool textiles requiring high levels of heat and flame resistance are limited in the main to the contract and transport furnishing fabric and protective clothing markets. The non-thermoplastic and char-forming characteristics of wool, coupled with an inherently quite high level of low flanunabiUty, make it an ideal fibre when handle, comfort, and aesthetics are also required. 

Fabrics should be tested after a defined wash or durability test which, in the case of Part 7, for fabrics treated with a flame retardant, is a single specified wash cycle. Only so-called durable flame retardant finishes as described in Chapter 8 will pass such a wash cycle since semi-durable treatments are usually only resistant to dry cleaning or simple water soak tests specified in BS 5651 1989, for example. Fabrics containing inherently flame retardant fibres such as Hi-modified polyester (e.g. Trevira CS ), polyacrylics (e.g. modacryUcs such as Kanekaron ), and polypropylene do not require a prewash treatment prior to testing. 

Cellulosics have certain deficiencies in properties that require finishing to improve these properties and maximize consumer usage and acceptance. The most important cellulosic finishes include crease resistant and stabilizing finishes, soil release and softening finishes (in conjunction with crease resistant finishes), oil and water repellant finishes, biologically protective finishes, and flame retardant finishes. 

Tris(2,3-dibromopropyl jphosphate (better known as Tris) was an ideal flame retardant for polyester and was used extensively for this purpose. Unfortunately, Tris was found to be mutagenic and a potential cancer-producing agent and had to be removed from the marketplace. As a result of the ensuing confusion, all topical flame retardant finishes have become suspect, and certain flammability requirements have been relaxed to allow polyester to pass the flammability test for children s sleepwear without further treatment. 

FWWMR Finish. The abbreviation for fire, water, weather, and mildew resistance, FWWMR, has been used to describe treatment with a chlorinated organic metal oxide. Plasticizers, coloring pigments, fiUers, stabilizers, or fungicides usuaUy are added. However, hand, drape, flexibUity, and color of the fabric are more affected by this type of finish than by other flame retardants. Add-ons of up to 60% are required in many cases to obtain... 

THPC—Amide—PoIy(vinyI bromide) Finish. A flame retardant based on THPC—amide plus poly(vinyl bromide) [25951-54-6] (143) has been reported suitable for use on 35/65, and perhaps on 50/50, polyester—cotton blends. It is appUed by the pad-dry-cure process, with curing at 150°C for about 3 min. A typical formulation contains 20% THPC, 3% disodium hydrogen phosphate, 6% urea, 3% trimethylolglycouril [496-46-8] and 12% poly(vinyl bromide) soUds. Approximately 20% add-on is required to impart flame retardancy to a 168 g/m 35/65 polyester—cotton fabric. Treated fabrics passed the FF 3-71 test. However, as far as can be determined, poly(vinyl bromide) is no longer commercially available. 

This product is a resinous condensation designed to provide flame retardancy to nylon. The application requires curing, certain water repellents may be incorporated into some finishes-contains formaldehyde. 

In order to obtain functional fibres and textiles to meet the special requirements for buUdtech applications, a large variety of properties can be engineered by finishing and post-treating fibres, e.g. for dirt or oil repellence, UV-protection, flame retardance, higher tensile strength or abrasion resistance. 

Traditionally, Zirpro -finished wool meets the above requirements and decabro-modiphenyl ether/antimony oxide-acrylic resin-fmished cotton fabrics (originally marketed as Caliban, White Chemical) have also been found to be suitable for workers in the aluminium industry. However, as discussed in Chapter 8, this latter finish is currently being withdrawn on environmental grounds and this whole area has recently been reviewed by Makinen, who lists more recent fabrics based on a variety of blends with flame retardant wool, viscose, and inherently flame retardant aramid fibres, for example. However, these factors are all different for molten iron or steel, copper, tin, lead, zinc, or aluminium and so protective aprons and overalls have to be tailored to fit the threat. Examples listed by Makinen for molten aluminium resistance include ... 

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