Classification of Reactive dyes
(A) Group 1: Alkali controllable dyes
(B) Group 2: Salt controllable dyes
(C) Group 3: Temperature-controllable dyes
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| Preparation of reactive dyes |
(Classification of reactive dyes can also be categorised as the below method.
1. Classification of Reactive dyes
2. Reactive Systems classification
3. Chemistry of Reactive dyes and classification)
Explanation :
The chronological development of reactive dyes and also the reactive systems are shown in the table below-
(A) Group A: Alkali Controllable dyes:
Low substantivity reactive dyes often described as Alkali controllable dyes exhibit rapid washing-off properties.Their level of dyeing Properties needs to be regulated by the slow addition of Alkali.
This is exhausting to encourage the migration of dye to the substrate during Alkali addition and also to forestall the phenomenon of simultaneous exhaustion and fixation fig. Below shows the extent of Exhaustion of an Alkali controllable reactive dye first within the presence of salt and then in presence of Alkali.
It is clear that S the Exhaustion percentage because of salt is moderate but, thanks to Alkali E, is much higher than F is that the overall fixation of the dye.
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| Exhaustion of alkali-controllable reactive dyes |
(B) Group B: Salt controllable dyes :
Medium to high substantive reactivity dyes often described as salt controllable dyes, exhibit slow(poor) washing-off characteristics.
Their level dyeing characteristics must be controlled during the electrolyte addition stage i.e by portion-wise addition of salt in giving below figure the Exhaustion percentage of this group of reactive dyes thanks to the salt (s) is far higher because Alkali (E) is lower.
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| Exhaustion behaviour of salt-controllable reactive dyes |
(C) Group 3: Temperature-controllable dyes-
When there is no alkali present, these colours react with cellulose above the boiling point. With alkali fixation occurring between 80 and 100°C, they can be used similarly to group 2. Self-levelling dyes are what these are. The temperature can be controlled well.
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| Reactive dyeing |
Questions -
- Which are the types of dyes according to controllable reactive dyes?
- Describe alkali controllable reactive dye.
- Describe salt's controllable reactive dye.
- Describe temperature-controllable reactive dye.
References
Ahmed, S. (2014, September 29). Reactive dyes - classification. TextileTuts. https://textiletuts.com/reactive-dyes/
Chakraborty, J. N. (2010). Waste-water problem in textile industry. In Fundamentals and Practices in Colouration of Textiles (pp. 381–408). Elsevier.
Clark, M. (2011). Handbook of textile and industrial dyeing: Principles, processes and types of dyes (Matthew Clark, Ed.). Woodhead Publishing.
No title. (n.d.). Acs.org. from https://cen.acs.org/articles/96/i29/new-textile-dyeing-methods-make.html
Patwary, E. M. Z. (2012, February 18). Reactive dyes. Textile Fashion Study; Engr. Mohammad Zillane Patwary. https://textilefashionstudy.com/reactive-dyes-definition-classification-properties-and-influencing-factors/
Sayed, A. (n.d.). Why reactive dye is so called? Blogspot.com. from https://textileapex.blogspot.com/2013/11/reactive-dye.html
What are Reactive Dyes? Types of Reactive Dyes. (n.d.). Meghmaniglobal.com. from https://www.meghmaniglobal.com/what-are-reactive-dyes-types-of-reactive-dyes/
Continue reading,
Part 2 Classification of Reactive dyes
Part 3 The reaction of MCT and DCT of reactive dyes
Part 4 General Factors affecting the results of reactive dyeing
Part 5 Reactive dyeing method - DCT
Part 6 Bifunctional systems of reactive dyes
Part 7 Development of reactive dyes
Part 8 Reactive dyes on Silk and nylon with their application
Part 9 Industrial applications of reactive dyes
Part 10 After treatment of reactive dyes
Writer - Rushikesh Patil (Textile Engineer)
