Burkinshaw, SM orcid.org/0000-0001-9940-1354 and Salihu, G (2019) The role of auxiliaries in the immersion dyeing of textile fibres: Part 5 practical aspects of the role of inorganic electrolytes in dyeing cellulosic fibres with direct dyes. Dyes and Pigments, 161. pp. 581-594. ISSN 0143-7208
Abstract
Both the colour strength of 2% omf dyeings and the extent of dye exhaustion achieved for three commercial grade direct dyes on cotton were promoted by the addition of 20 gl−1 NaCl at each of eight liquor ratios (1:50, 1:20, 1:10, 1:6, 1:3, 1:2, 1:1.5 and 1:1). The extent of electrolyte-enhanced dye uptake decreased with decreasing liquor ratio. For each of the three dyes, unlevel dyeings were obtained at 1:1 liquor ratio only in the presence of added electrolyte, whereas level dyeings were secured even at 1:1 liquor ratio in the complete absence of added electrolyte. The depth of the dyeings obtained in the absence of added electrolyte using both 1:1 and 1:1.5 liquor ratios were of similar magnitude to those secured using 1:10, 1:20 and 1:50 liquor ratios in the presence of 20 gl−1 NaCl. The promotion of dye uptake imparted by both added electrolyte and reduced liquor ratio were interpreted in terms of their effects on the substantivity of the direct dyes towards the cotton substrate. It is proposed that adding electrolyte to the dyebath and reducing the liquor ratio employed for dyeing have the same consequence in terms of enhancing dye uptake, namely that of encouraging dye aggregation in the dyebath which reduces the aqueous solubility of the anionic dye, which, in turn, results in the inherent preference of the dye to favour the aqueous phase shifting towards the fibre phase.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 Elsevier Ltd. All rights reserved. This is an author produced version of a paper published in Dyes and Pigments. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Dyeing cotton; Dyeing auxiliaries; Electrolyte; Direct dyes; Salt-free dyeing |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Arts, Humanities and Cultures (Leeds) > School of Design (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 19 Sep 2017 08:45 |
Last Modified: | 23 Nov 2018 09:29 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.dyepig.2017.09.002 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:121406 |