Zirpro® process

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... 

Zirconocenium cations, 76 95 Zircon pigments, 79 404-405 Zircon refractories, ASTM classifications and specifications for, 27 509-510 Zircon sands, 73 81 analysis of, 26 623t Zirpro Process, 26 404 Ziziphin, 24 246 Zn-Ag cartridges... 

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... 

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). 

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. 

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. 

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... 

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