Dye classification
Dyes can be categorised according to several factors such as colour, synthetic route, fibre type, the method of application to the substrate and chemical structure, etc.
Classification of dye by method of application (click each for more information):
Direct dyes
Substrate
Mainly used for cellulosic fibres: cotton, viscose, linen. Can also be applied on silk and wool.
Method
Applied directly to the substrate in a neutral or alkaline bath.
Fastness
Give bright shades but exhibit poor wash and light-fastness. After-treatments with dye fixing agent.
Reactive dyes
Substrate
Commonly used for all cellulosic fibres: wool, silk and rayon.
Method
Reacts chemically with the fibre being dyed.
Fastness
Very good fastness properties.
Vat dyes
Substrate
Cotton, linen, rayon, wool, silk and sometimes nylon.
Method
Insoluble in water. Requires reduction treatment to make soluble in water and oxidation to resume insoluble state after dyeing.
Fastness
High fastness to chlorine, washing, light, rubbing and boiling.
Sulphur dyes
Substrate
Cotton, linen and rayon.
Method
Insoluble in water, similar to vat dyes.
Fastness
Excellent resistance to washing but poor resistance to sunlight.
Azoic dyes
Substrate
Cotton, linen and viscose.
Method
Insoluble in water. Two components react to produce the dye (Coupling Compound (Naphthol) and Di‐azo –compound).
Fastness
Good fastness properties.
Metal complex dyes
Substrate
Wool, nylon and silk.
Method
Pre-metallised dyes, pH<7.
Fastness
Good fastness properties due to high molecular size and metal complex structure.
Acid dyes
Substrate
Wool, nylon and silk.
Method
Applied from a dye bath containing acids.
Fastness
Fastness properties may vary among individual dyes and fibre types.
Disperse dyes
Substrate
Nylon, polyester and cellulose acetate.
Method
Insoluble in water, pH 4-5. Diffuse into the fibre at high temperatures.
Fastness
Good fastness properties.
Basic dyes
Substrate
Mainly used for Acrylic.
Method
Generally pH<7. Reaction with acidic groups.
Fastness
Good fastness properties.
-
Project
Contact
This resource was developed as part of an Erasmus+ project, funded with support from the European Commission under grant agreement 2016-1-SE01-KA203-22064.
The project was a collaboration between:
- The University of Borås, Sweden
- The University of the Highlands and Islands, Scotland
- The University of Alcalá, Spain
- Digital Connections, Scotland
This resource has been released under Creative Commons license CC-BY-SA 4.0.
Disclaimer
If you would like more information on this resource please contact:
- Academic content – The University of Boras (www.hb.se)
- Technical resource development – The University of the Highlands and Islands Educational Development Unit - EDU (edu@uhi.ac.uk)
Except where otherwise noted, this website is licensed under Creative Commons license CC-BY-SA 4.0. All images used under permission remain the copyright of the license holder.
Download a copy of this resource in PDF format.
You can also print individual pages by printing directly from the browser.
-
