The Bleaching of Cotton Yarn.

Practical Magazine 24, 1876

(Chemistry applied to the Arts, Manufactures, &c.)

M. L. Toussaint recommends the following method of bleaching cotton yarn:

— Let 220 lbs. of cotton yarn be bucked for eight hours in a soda lye composed of 6½ lbs. of crystallized soda and 2¼ lbs. of slaked lime. After being steeped in the bucking caldron and washed, the yarn is put into a solution of chloride of lime; remains there two hours, and goes direct thence to the diluted sulphuric acid, in which it remains for twenty minutes. The above-mentioned quantity of yarn requires 11 lbs. of chloride of lime powdered, and 1 1/6 part of sulphuric acid.

After the bleaching, the yarn should be carefully washed in flowing water, and then put — sometimes twice — into a soap bath containing 1 kilogramme (2.2 lbs.) of palm-oil soap for every 100 kilogrammes (220 lbs.) of yarn. By this means the cotton is freed from the adhering acid, and can now be sized — warp yarn with 6 kilogrammes (13.2 lbs.) and woof yarn with 2 kilogrammes (4.4 lbs.) of starch for every 100 kilogrammes (220 lbs.), with the addition of some acid-proof ultramarine. Cotton yarn so treated is quite uniformly bleached, and continues beautifully white in the warehouse, whether in skeins or textures.

- Moniteur Industriel Belge.