Properties and Application of Mineral Khaki Dyes on Cotton
Shareful Islam Palash
Lecturer, Institute of Textile Engineering & Information Technology
Email: palash313@gmail.com
Mineral Khaki Dyes:
Mineral khaki is also called metallic khaki. Mineral khaki color produces by the dyeing process of Iron buff and chrome green color mixing. It’s generally applied on cotton. This cannot applied on silk or wool. Because, this dyes decrease the flexibility and luster of silk and wool. Mineral khaki color produces by chemical reaction of metal salt. These classes dyes are chrome yellow, chrome orange, chrome green, manganese brown, iron buff, khaki, prussian blue etc. Generally military / police uniform are dyed with mineral khaki dyes. It has excellent water fastness because the insolubility of the metal oxides in water. Involves a series of chemical reaction to make the process economical.
Define Mineral Khaki Dyes:
By mixing of 50% Iron buff and 50% chrome alum solution, which military khaki color is produces, it’s called mineral khaki dyes. Its other name is Military khaki dye.
Properties of Mineral Khaki Dyes:
- This dyes are generally applied on cotton fibers.
- It’s light fastness and washing fastness is good.
- This color dyed fabric is decrease by acid.
- It’s used for military dress dyeing.
But it is now very unknown in the market.
Application of Mineral Khaki Dye on Cotton:
The process of mineral khaki dyeing by impregxiation with chrome alum and iron alum, followed by development with potassium chromate, deposits chromium and iron chromates on cotton. These compounds are hydrolysed and reduced by subsequent washing and drying of the dyed yarn, the ultimate pigment being a mixture of hydrated chromic and ferric oxides.
1st Method:
Recipe:
- Iron buff/ferrous sulphate——3-5% o.w.m. [On the weight of materials]
- Sulphuric acid——————-2-3% o.w.m.
- Potassium bichromate———-2-3% o.w.m.
- Temerature———————-90-99oC.
- Time—————————–30-60 minute
- M:L——————————1:20
Process Sequence:
At room temp. set the dye bath with some hot water and Iron buff /Ferrous sulphate. After sometimes Potassium bichromate and sulphuric acid add on the bath and add the rest water. Raise temperature at 50oC. and add fabric on the bath.The temperature raise at 99oC. and run the dye bath about 60 minute. After dyeing the fabric washing and found khaki color.
2nd Method:
Recipe:
- Chrome alum———-5% o.w.m.
- Ferric chloride———5% o.w.m.
- Soda——————-10%o.w.m.
- Temperature———–90-99oC.
- Time——————-30 minute
- M:L———————1:20
Process Sequence:
- Set the dye bath with required water.
- Add Chrome alum and ferric chloride.
- Add fabric into dye bath solution and raise the temperature at 90-99oC.
- Rum time of dye bath is 30 minute.
- Cool down the dye bath and bath drain.
- Soda solution makes in the other bath and add the dyed fabric in it to produces color.
- Raise the temp.at 99oC. about 30 minute.
- Soaping the goods at 90oC. and washing by cold water as after treatment.
Conclusion:
Different khaki color also produces by mixing of different % of chrome and Iron buff with manganege salt. If It’s used in textiles, but It is now very unknown in the market. It’s used for only military dress dyeing. Mineral khaki- dyed cloth is often over dyed (topped) with Vat Khaki. If the entire shade is built up with these vat dyes, the dyeing process becomes costly. In order to reduce the cost of dyeing, a major part of the shade is produced by the mineral khaki and topped with a small percentage of the vat dye.
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Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
