Jute Yarn Dyeing With Basic Dye

In this article, we are going to describe the dyeing process of jute yarn. The steps are described below as followed in the lab.

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Theory

Basic dyes are also known as cationic dyes. This is a class of synthetic dyes, that act as bases, and when soluble in water, they form a colored cationic salt that can react with the anionic sites on the surface of the substrate. It is suitable for jute yarn. The chemical composition of jute is complex. It contains cellulose, hemicellulose, and lignin as the major constituent. This fiber is very sensitive to alkali due to the presence of hemicellulose, and the presence of cellulose makes it sensitive to strong acids. So jute fiber and its generated products are treated with basic dyes.

Objectives

To know about jute yarn.
To know about basic dyestuff.
To know the procedure of dying with basic dye.
To know about chemical auxiliaries.

Recipe

Chemicals / Parameters	Quantity
Basic dye	2%
Wetting agent	0.5 g/L
Sequestering agent	1 g/L
Acetic acid	1 g/L
Glauber salt	10 g/L
pH	4.5-5.5
M:L	1:40
Time	20 mins
Temperature	100℃

Calculation

M:L (Material: Liquor) = 1:40 (M:L is more because it is done in the open bath)

Fabric: 5 gm

So, liquor = (5 ✕ 40) = 200 ml

M:L = 5:200

We know, Dye = (Sample weight ✕ Shade %) / (Stock solution %)

For 2% shade and 1% stock solution,

= (3 ✕ 2%) / (1%) = 6 ml

Again, Chemical : (g/L ✕ Total liquor) / (1000 ✕ Stock solution %)

For 5% stock solution wetting agent required = (0.5 ✕ 200) / (1000 ✕5%) = 2 ml

For 5% stock solution sequestering agent required = (1 ✕ 200) / (1000 ✕ 5%) = 4 ml

Thus, calculated total chemicals.

Now, freshwater needed = (200 – Total chemicals) ml

Sample of Basic Dyed Jute Yarn

Basic Dyed Jute Yarn

The Curve of Basic Dyeing

Basic Dyeing of Jute Curve

Auxiliary Chemicals Functions

Basic dye: Basic dyes are cationic soluble salts of colored bases. Basic dyes are applied to a substrate with an anionic character, where electrostatic attractions are formed. Basic dyes are called cationic dyes because the chromophore in basic dye molecules contains a positive charge. The basic dyes react on the basic side of the isoelectric points. Basic dyes are salts, usually chlorides, in which the dyestuff is the basic or positive radical. It is a powerful coloring agent. It is applied to wool, silk, cotton, jute, and modified acrylic fibers.

Wetting agent: It accelerates the wettability of material in solution, thus helping the easy penetration of chemicals into the substrate. It reduces the surface tension of water to allow it to spread drops on a surface, increasing the spreading abilities of a liquid.

Acetic acid: Its function is to control pH in the process.

Sequestering agent: In the absence of a water softening plant in an industry, it is also possible to reduce the unwanted interference of heavy metal ions during soaping or dyeing by a sequestering agent. A sequestering agent is a substance that suppresses a property or reaction of metal ions without the removal of that metal from the system. The most common sequestering agent is EDTA, known as ethylenediaminetetraacetic acid.

Glauber salt (Na₂SO₄. 10H₂O): This salt is used as electrolyte. It reduces or extinguishes the charge on the fiber, to color fabric.

Conclusion

Jute is a natural bast fiber. Jute fabrics are printed with basic dyes. Basic dyes printing is carried out in an acidic medium. Different types of attributes are added with jute fabric for making it user-friendly. Nowadays, jute dyeing and printing becomes popular.