GB588700A - Improvements in the elimination of cellulose ester fibres from mixed textile materials containing wool - Google Patents

Abstract

Wool is recovered from mixed textile materials containing wool and cellulose organic ester fibres by immersing the materials in an aqueous bath containing a saponifying agent for the cellulose ester and an inorganic salt which inhibits the destructive action of the saponifying agent on the wool, until the cellulose ester fibres have been converted into regenerated cellulose fibres and then carbonizing the cellulose fibres in the treated material. The saponifying agent may be sodium, potassium or ammonium hydroxide, sodium carbonate, sodium silicate, methylamine, ethylene diamine or triethanolamine. Sodium hydroxide of 0.1 to 1 per cent strength may be used. The inhibiting salt may be sodium sulphide or sodium chloride. The treatment may be effected at 10-50 DEG C. Carbonizing may be effected by treating the textile material with sulphuric acid, hydrochloric acid, or aluminium chloride, or other carbonizing agent in solution or vapour form, and then after a preliminary drying if necessary, subjecting the textile material to a baking operation. After baking the dried material is shaken, neutralized, rinsed and dried. The mixed textile material may be subjected to a treatment to remove or lighten any colour effect prior to being subjected to the saponification treatment, e.g. it may be treated with sodium hydrosulphite solution. The textile material may be in the form of waste fibres or in the form of a fabric, e.g. a fabric containing wool and cellulose acetate fibres with or without cellulose fibres. Decorative effects may be obtained by weaving a fabric of wool and cellulose acetate fibres and then removing all of the non-woollen material.