bleaching, paper-pulp

Значение термина bleaching, paper-pulp в knolik

1. The washed substances are put into a weak bath containing 6¼ to 8 lb. bleaching powder per 22 gal.; after 6 to 12 hours they are washed and boiled for 2 to 4 hours with carbonate of soda (1 oz. per gal.). If the fibres are very hard, they are treated with sulphuric acid (⅓ oz. per gal.), and well drained before boiling with the soda. Finally they are placed in a bath of 6¼ to 8¼ lb. of bleaching powder and 1¾ lb. of soda per 22 gal. for 4 to 6 hours.
2. The fibres are passed through an alkaline chlorine bath, containing excess of caustic alkali; 5 per cent, is used for linen, cotton, etc., 25 per cent, for jute and other substances difficult to bleach. The temperature should not exceed 122 ° F. (50 ° C.). The bath is readily made by adding excess of soda carbonate to chloride of lime.

Рядом со словом bleaching, paper-pulp в knolik