Zirpro wool

It was claimed i that Zirpro wool fabric assemblies showed a relatively longer time to reach pain (first degree burn) and blister (second degree burn) thresholds, as well as the longer pain alarm time - the time available to the wearer to withdraw from the flame heat source before serious injuries occur. It is also claimed that, compared with some other fibres including... 

When used in flreflghters clothing, it was found that a woven Zirpro wool fabric of high density over a bulky knitted Zirpro wool underwear fabric offered signiflcantly better protection than a single layer of a woven or knitted fabric or a double layer of a woven fabric of the same total weight. 

However, the Zirpro wool treatment process and Zirpro wool products have certain problems. Firstly, both the zirconium and titanium hexafluo-rozirconate salts used in Zirpro wool treatment have associated potential... 

Benisek L, Edmondson GK and Phillips WA (1979), Protective clothing Evaluation of zirpro wool and other fabrics, Fire and Materials, 3(3), pp. 156-166. 

Flame-Retardant Treatments For Wool. Although wool is regarded as a naturally flame-resistant fiber, for certain appHcations, such as use in aircraft, it is necessary to meet more stringent requirements. The Zirpro process, developed for this purpose (122,123), is based on the exhaustion of negatively charged zirconium and titanium complexes on wool fiber under acidic conditions. Specific agents used for this purpose are potassium hexafluoro zirconate [16923-95-8] [16923-95-8] K ZrF, and potassium hexafluoro titanate [16919-27-0], K TiF. Various modifications of this process have been... 

Shrink-resistance processes compatible with Zirpro-treated wool have also been developed (166). 

Zirpro A process for flame-proofing textiles by treating them with aqueous solutions of zirconium complexes. Wool is treated with aqueous potassium hexafluorozirconate and citric acid. Developed by the International Wool Secretariat, Yorkshire, now based in Melbourne, Australia. 

Zirconium complexes have found worldwide use in increasing the flame resistance of wool (ZIRPRO process).24 The fabric is treated with a hot aqueous mineral acid solution containing ZrOCl2 and an a-hydroxy acid such as citric or tartaric acid. The nature of the species existing in the solution appears to be unknown, but a-hydroxycarboxylate chelates are thought to be involved.25... 

Wool Wool, though not as flammable as cotton, still needs flame retardation for specific applications, e.g., carpets, upholstered furniture in transport, etc. Ammonium phosphates and polyphosphate, boric acid-borax, and ammonium bromide can be successfully used in nondurable FR finishes for wool. Various commercial products have been reviewed by Horrocks.3 The most successful durable treatment for wool is Zirpro, developed by Benisek, which involves exhaustion of negatively charged complexes of zirconium or titanium onto positively charged wool fibers under acidic conditions at 60°C. The treatment can be applied to wool at any processing stage from loose fiber to fabric using exhaustion techniques. 

Even an antagonistic behaviour is reported for wooFpolyester blends. Both Zirpro finished wool and Trevira CS, which is inherently flame retardant modified... 

It should be reahsed also that often when wool is to be used in protective clothing as well as transport upholstery applications, the use of multipurpose finishes is important and their compatibility with the Zirpro present are essential. Such finishes may mclude ... 

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 ... 

Part 5 is relevant to floor coverings since these are required to have a surface with low flame spread characteristics and are tested in accordance with Resolution A.653(16). This defines a method of determining surface heat spread in a vertical orientation under a heat flux of 49.5 kWm" at the initial part of the sample length reducing to 1.5kWm- after 740 mm. Thus carpet fabrics must have higher flame resistance than normally expected for such a horizontally orientated textile. Consequently, flame retarded wool (e.g. Zirpro -treated wool see Chapter 8) will feature as an important fibre in appropriate woven or tufted stractures which combine both the necessary aesthetic and technical requirements. 

Protective clothing e.g. workwear Barrier fabrics e.g. theatre curtains Furnishings and interior textiles Pyrovatex -treated FR cotton Proban -treated FR cotton FR wool (e.g. Zirpro ) FR viscose (e.g. Lenzing FR, Visil ) FR polyester (e.g.Trevira CS ) FR acrylic (e.g. Kanecaron)... 

Potassium Hexafluorozirconate [16923-95-8]. This water-soluble com-poimd is a flame retardant for wool by the Zirpro process. Applied in combination with formic acid and citric acid, the fluorozirconate exhausts onto wool and after mild heating, provides a fairly wash-dimable flame-retardant finish. Wool upholstery for aircraft makes use of this treatment (19). 

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