Verfahren zur Unterdrueckung des charakteristischen Geruchs von Keratinfasern

In a process for permently setting fabrics containing keratin fibres in a desired configuration, e.g. creased, pleated or flat configuration, or for presensitising such fabrics by imparting a propensity for permanent setting thereto, including the steps of contacting the fibres with a reducing agent and heating, the characteristic odour of reducing agent treated fibres is substantially reduced or eliminated in the permanently set fabric formed, or which can be formed by setting the presensitised fabric, by contacting the fibres before or after making into the fabric with the reducing agent in the presence of an aldehyde-generating compound which will release an aldehyde at the elevated temperatures required to set the fabric. Suitable aldehyde generating compounds are paraformaldehyde, polyoxymethylenes, formals, methylol alkanolamine sulphites, methylol amides, hexamethylene tetramine, trimethylolmelamine and alkali metal formaldehyde disulphites. Suitable reducing agents are zinc or sodium formaldehyde sulphoxylate, sodium or potassium borohydride, bisulphite, sulphite, metabisulphite or hydrosulphite, thioglycollic acid, sodium, potassium or ammonium thioglycollate, hydrogen sulphide, sodium or potassium hydrosulphide, butyl or ethyl mercaptan, b -mercapto-ethanol, ammonium bisulphite, sodium sulphide, cysteine hydrochloride, sodium hypophosphite, thiosulphate or dithionate, titanous chloride, sulphurous acid or mixtures thereof. In the production of presensitised fabrics the fabric may be treated with the reducing agent and dried and subsequently made into garments and/or arranged in a desired configuration if necessary after spraying with water and then heated. If the presensitised fabric is not sprayed with water prior to heat setting the reducing agent solution may contain a polyhydroxy compound having a molecular weight no greater than 4,000 or a swelling agent, e.g. urea, guanidine hydrochloride, formamide, N,N-dimethyl formamide, acetamide, thiourea, phenol or lithium chloride, bromide or iodide. The presensitisation process may also comprise treating the fabrics with a reducing agent precurser, e.g. an alkanolamine or other amine, alkali and alkaline earth metal hydroxides, carbonates, borates or phosphates, aldehydes and ammonia, finishing by conventional mill finishing operations, e.g. semidecatising, and then exposing them to a gaseous reducing agent activator, e.g. SO2, hydrogen sulphide, methyl or ethyl mercaptan, 2-mercaptoethanol, nitroge