Cotton dyeing with sulfur black dye

Defectively dyed apparel is made into one or more batches to dye with sulfur black dyes.

Process of Cotton dyeing:

• L: R = 1: 10 (for 150 kg)
• 60 kg salt @ 40% of liquor
• Raise temp. to 60º C by steam supply.
• After 15 min add sulfur black @ 12% + Sodium Hydrosulfide @ 14% of liquor
• Raise temp. to 80º C and continue processing for 120 mins.
• Raise temp. to 90º C add Sodium Carbonate @ 5%. Continue processing for 60 mins.
• Reduce dyeing temp. 70º C and drop the dye liquor

• To remember unfixed dye, a hot wash at 50º C with 0.5% detergent for 15 minutes with 1500 liter water. Continue washing for 5 mins without temperature 
• Sulfur black-dyed garments if stored, may form sulfuric acid which will reduce garment strength. To avoid this, 3% unidol SF paste may be used.
• Dyeing with sulfur dye is very dirty work for m/c, the floor, operators & environment should be cleaned well for further processing. 

Cotton sweater dyeing with pigment:

1. Pretreatment (Bleaching, scouring)

 2. Singeing:

Cellulose (Denimex 992 L)) Enzyme @ 1 g/L

Acetic acid = P^H 4.5

Temp. = 55⁰C

Time= 30 min

3. Pigment dyeing:

Cationic agent (Prifix K) 1g/L

Soda ash = P^H 8.5

Pigment Red H3BD @ 0.5% anionic pigment forms a bond with cationic cotton

Binder @ 1g/L forms a preliminary net structure with pigment and fabric

4. Washing:

Softener 0.5 g/L

Acetic acid = 5.5 P^H

• During drying, the final fixation of the binder takes place.

Md Mahedi Hasan

Mahedi Hasan working as an Executive (Fabric Marketing) at Pengnuo Group. Graduated with B.Sc. in Textile Engineering. Before was a Top Rated content writer at Upwork, and Level 02 Seller at Fiverr, Level 02 Publisher at Ezoic. Very passionate about content writing, SEO practice, and fashion website designing. Highly Experienced fashion writer for the last 4+ years. Have extensive 7 years of experience in the wholesale clothing business.