| 摘要 |
Natural impurities in cotton, linen, jute, &c., are removed by boiling the material in the presence of ordinary or true mahogany sulphonates. The process may take place in aqueous solution at atmospheric pressure, the material being passed continuously through the solution. With a solution containing 0,1 per cent to 2 per cent of sulphonate and 1 per cent sodium hydroxide, a boiling lasting 30 minutes suffices. In an example, samples of duck &c. were boiled for an hour at atmospheric pressure in solutions containing from 0,25 per cent to 2 per cent of sodium hydroxide and the same proportions of sulphonates. After rinsing they were immersed for a few minutes in a 2 DEG Tw. bleaching powder solution and exposed to the air for an hour. After rinsing and souring with 1 per cent hydrochloric acid they were rinsed and dried. Specifications 247,940 and 252,051, [both in Class 2 (iii), Dyes &c.], are referred to. |
