Helo, redars today I m going to explain about exllent information of sulphur dyeing, properties, dyeing process, recipe, fults and more. I m writing all information about Sulphur dyeing process with my personal view.
• Sulphur dye having ability to produced heavy materials such as rubber materials or more.
• Wool and proteins fibres production is not possible for dyeing.
• Sulphur dyes having not ability to produce other colour shade such as red, orange, yellow.
• Sulphur dyes is more suitable and profitable dyes for cellulose.
Sulphur dye properties
– Sulphur dyes are insoluble in water.
– Sulphur dyeing is favourable cost structure.
– Alkaline condition is required for dyeing.
– Sulphur dyeing is one of the most popular for black, brown and blue shade production.
– Sulphur dyes are not more costly process.
– electrolyte is used for exhaust dyes.
– After treatment is required for shade development.
– oxidation treatment is required for shade development in case of Sulphur dyeing.
– Striping is required for uneven dyeing.
– Sulphur dyes is also used for dyeing and printing.
sulphur dyes characteristics
In case of Sulphur dyeing here the main characteristics given below
– oxidation chemical treatment is required for colour and shade devlopment.
– washing fastness is good because the dye particle of sulphur dye is big and insoluble in water
– In case of sulphur dyes, dye particle of sulphur dye is converted into leuco form with the treatment of dilute aqueous
– dyeing is done properly because sulphur dyes contain dye -S -S – dye
dye – S-S – dye
/ Di sulphide
– Sulphur dyes are reoxidized after dyeing by air.
– hydrogen peroxide is also used for oxidation in sulphur dyeing.
– No more costly process
Sulphur dyeing process
Sulphur dye – 8 – 12%
Reducing agent – 8 g/l
Alkali (Na2CO3) – 10 g/l
NaOH – 5 g/l
Salt (NaCl) – 10 g/l
Wetting agent – 1 g/l
Sequestering agent – 1 g/l
Leveling agent – 1 g/l
Time – 40 minute
Temp – 80°c
Chemically Fuction in Sulphur dyeing
1. Role of leveling agent
• lower the initial rate of dyeing.
• Control the migration steps of dye.
• if the levelling agent is not use then double dye to dyed the fabric.
2. Role of Wetting agent
• Reduce surface tension with the help of wetting agent because if wetting agent is add in dye bath then it reduces surface tension, results dye is enter properly in to the fibre.
3. Role of Sequistering agent
• sequistering agent is used during dyeing because it control increase hardness of water.
In simple water some unwanted ions are persent such as maganasim or more and this water is not proper for dyeing.
This is the reason, sequistering agent is add in dye bath it help to remove hardness of water and it’s also remove unwanted ions.
4. Role of Reducing agent
Sulphur Dyeing method
• steps – 1
first of all add dyeing chemicals such as, levelling agent and then add wetting agent. Temp will be 40°c of bath.
• steps – 2
Add dye solutions in same temp.
• steps – 3
Introduce fabric in dyeing bath.
• steps – 4
Add 1/2 salt in dyeing bath and then raised temperature up to 60°c.
• steps – 5
Again add 1/2 salt and the again raised the temp up to 90°c. and dyeing continue at same temperature. and dyeing time will be 40 mint.
• steps – 6
And then cooling – rinsing – washing – after treatment is carried out for shade development.
Sulphur dyeing (faults)
Here, if tendering broblme will occur on the fabric. then wash properly with CH3COONa.
In case of Sulphur dyeing, Bronziness fults is directly related with shade change or colour change. Shade is not properly match with required shade or colour.
This is also a big fults in case of Sulphur dyeing. Shade is not matching after dyeing.
But this problem is also solved by using some useful chemicals.
Use NaHSO3 in conjunction with NaOH and Na2S.
This is a simple process.
treat with boiling soap soon
Soaping chemicals – 1 g/l
Temp. – 95° to 100°c
Time. – 10 – 20 mint
• Textile Sulphur dyeing process is not more costly.
• Sulphur dyes having ability to produced deep shade product.
• Sulphur dyes are also used in printing.
• wash fastness and light fastness is good.
• dyeing process is done with low energy.
• Sulphur dyes are available in powder form or also soluble form.
• manufacturing process is done easily.