| 摘要 |
The short-time pad-batch process for dyeing cellulose fibres with reactive dyes using soluble waterglass (sodium silicate) in the alkaline padding liquor has the following disadvantages: (a) The treatment of the wastewater is made more difficult; (b) feed and discharge lines can become blocked; (c) long runs cause impairment of the padding process and damage to the pad-mangle. These constantly recurring difficulties, which are due to the use of water-soluble sodium waterglasses, were reason enough to investigate buffer alkalis similar to waterglass. Surprisingly, finely divided, virtually water-insoluble silicas, or sodium aluminium silicates, show similar favourable properties to the waterglasses. In contradistinction to the latter, however, the former are easy to separate off, are readily washed off and therefore do not interfere with treatment of the wastewater. Blocking of lines due to SiO2 deposits is not possible.
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