Solutions
Issues with Water Based Dyeing System
Poor dye pick-up and limited dye fixation rate- Large amounts of water consumption
- Large amount of electrolytes and other chemicals
- Large amount of waste water with dye, electrolyteand chemical residuals (high COD and colored)
The key to the problem lies in the use of water as the dyeing medium
We invented an original technical system to overcome the shortcomings of existing dyeing
• Highly water-saving, zero sewage discharge
• Unsalted dyeing
• The dyeing rate and fixing rate are greatly improved
• Dyeing cost is comparable to traditional dyeing
• Broad spectrum and applicability for large-scale applications
• The dyeing performance of textiles is comparable to that of traditional water baths
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01
Principle of Non-Aqueous Medium Dyeing
Characters for Non-Aqueous Medium Dyeing
• Dyeing medium is used as a processing aid, not a solvent for dyes and it is fully recovered after dyeing.
• Small amount of water as dyeing aid to dissolve dyes and help dye penetration and fixation.
• Using natural affinity between water and fibers, leading to almost 100% dye pick-up and no salts are necessary for dyeing.
• Low temperature is preferred for a uniform dyeing, leading to low dye hydrolysis, high fixation and low energy consumption.
• Water demand for after washing is significantly reduced due to much higher dye pick-up and fixation.
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02
Almost 100% Dye Pick-up
•In non-aqueous dyeing, dye uptake is controlled by amount of water in the system. The dye uptake is almost 100% without adding any salts.
•Dye loss during soaping/rinsing is also very limited due to very high dye fixation（>90%) for most of reactive dyes.
•The dyeing has a good dye penetration into cotton fibers.
Dye Penetration Study
Cotton
Water Based
Siloxane Based
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03
Hydrolysis of Reactive Dyes
HPLCAnalysis
Dye Structure
Dye Hydrolysis Route
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04
Dye Hydrolysis at different stages
• Fixing rate above 90% for reactive dyeing, increased from 60-70% for aqueous dyeing.
• Dye hydrolysis mainly happens at the fixing stage.
Dye I
Dye II
Dye III
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05
Great textile sustainability benefits
May fundamentally change negative images of textile dyeing as aheavy pollution source.
Resource and pollution reduction using reactive dyeing cotton as an example
Cleancolor vs. H2O
Waste water from dyeing
100%
Waste water from washing
> 95%
Fresh water usage
> 95%
Dye & chemical usage
> 30%
Salt usage
100%
Energy consumption
20% - 50%
Dyeing time
15% - 30%
