| 摘要 |
For bleaching purposes, textile material is impregnated with an alkali-metal chlorite solution and then subjected for a short period to the action of an acid vapour. The duration of the vapour treatment may be less than two minutes. The impregnating bath may comprise an aqueous solution of sodium chlorite and a wetting and/or cleansing agent at a pH of about 8.5 obtained by the addition of sodium phosphate or sodium hydroxide. The acid vapour may comprise water vapour and formic acid at a temperature of 100-105 DEG C. After the vapour treatment the material may be neutralized and washed or rinsed, alkaline boiled and washed. A preliminary alkaline boiling before bleaching is said to be unnecessary. The material may be cotton and may be treated continuously in full width or as yarns, card slivers, unspun uncombed fibres, or cross-wound bobbins. |
