Bleaching
After the desizing and scouring processes, most of the fabrics retain slight colouration. The natural or acquired colour needs to be destroyed to bring the textiles to a white state. Bleaching will be essential if:
- pure white colour is needed in the finished textile;
- the fabric is to be dyed to a clear pastel shade;
- the fabric is to be printed.
Bleaching agents can be classified as:
- Oxidative bleaching agents
- Peroxy compounds (Hydrogen peroxide (H2O2))
- Chlorine based compounds (Sodium hypochlorite (NaOCl), Sodium chlorite (NaClO2)).
- Reductive bleaching agents
- Sulphur dioxide, Sodium hydrosulphite, etc.
Methods of bleaching
- Batch process:
- a defined weighed fabric is loaded into small machine;
- the process is carried out step by step.
- Continuous process:
- the fabric will travel through a long machine made up of a series of unites;
- each unit is specified for one step of the process.
Bleached (left) and unbleached (right) fabrics
© University of Borås
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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.
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