GB1084716A - Production of shrink-resistant wool - Google Patents

Abstract

Wool and wool-containing materials are shrink-proofed by wetting-out a continuous length thereof with an aqueous liquor containing (a) a wetting agent, e.g. an anionic or nonionic wetting agent such as a condensation product of trimethylnonylphenol with 6 moles of ethylene oxide, (b) a shrink-resistance-imparting halogen-free oxidising agent for wool, e.g. permonosulphuric acid or potassium permanganate, and (c) at least one water-soluble acid having a dissociation constant K greater than 1 x 10-3 at 25 DEG C or a water-soluble salt thereof, e.g. sulphuric acid, sodium chloride, sodium sulphate, sodium bisulphate or ammonium sulphate, immediately after wetting-out passing the material through the nip between a pair of rollers so to to ensure that the material is uniformly impregnated with a controlled amount of the liquor while maintaining the controlled amount of liquor in contact with the material until at least a desired amount of the oxidising agent has reacted with the wool with which it is in contact, and feeding metered quantities of aqueous solutions of the oxidising agent, wetting agent and water-soluble acid or salt to maintain a substantially constant composition, the quantities being correlated with the rate of pickup of liquor by the materials so that (a) the volume of liquor remains substantially constant and (b) complete renewal of the liquor takes place in 1 - 15 minutes. The wool may be in the form of yarns, tops or woven or knitted fabrics. The material may be wetted with the aqueous liquor either by immersion for 1 - 2 seconds or by spraying, and the pickup of the aqueous liquor at the nip may be 50 - 250%. The treated material may subsequently be washed with water, passed through an aqueous solution of a reducing agent, e.g. sodium sulphate or acidified sodium bisulphite, again washed with water and finally dried.