SHRINKPROOFING WOOL WITH OXIDIZING AGENTS USING FOULARD LIQUID APPLICATION TECHNIQUE

摘要

Wool and wool-containing materials in the form of continuous lengths, e.g. yarns, tops and woven and knitted fabrics, are shrink-proofed by wetting them out with an aqueous liquor containing (a) a wetting agent, e.g. an anionic or nonionic wetting agent, and (b) at least two shrink-resistance-imparting oxidising agents for wool which react with woollen fibres at markedly different rates and together produce a shrink-resistant effect thereon, immediately after wetting-out passing the wetted-out material through the nip between a pair of rollers to ensure that the material is uniformly impregnated with a controlled amount of the aqueous liquor and maintaining the controlled amount of liquor in contact with the material until at least a desired amount of each of the chemical reagents has reacted with the wool. Metered quantities of aqueous solutions of each of the oxidising agents and wetting agent may be fed into the aqueous liquor to maintain the desired composition thereof, the quantities being correlated with the rate of pickup of liquor by the woollen materials being treated so that (a) the volume of liquor remains substantially constant and (b) complete renewal of liquor takes place in 1-15 minutes. The oxidising agents may be an alkali metal permanganate and an alkali metal or calcium hypochlorite at pH values of 5-10, permonosulphuric acid and an alkali metal dichloroisocyanurate at pH values below 5, permonosulphuric acid and sodium or potassium hypochlorite or peracetic acid and sodium or potassium hypochlorite. The pick-up of aqueous liquor at the nip may be 50 -250% by weight. The material may be wetted with the aqueous liquor which may also contain magnesium sulphate either by immersion for 1-2 seconds or by spraying. The treated material may subsequently be washed with water, passed through a dilute aqueous solution of a reducing agent, e.g. sodium sulphite or sodium bisulphite which may also contain formic acid, again washed with water and finally dried.