The components of the dyeing process:
The following three things are required for each dyeing process:
1) Substrate
2) Dye
3) Environmental factors
Table of Contents
1) Substrate:
The substrate is the object on which the dye will be applied. Fiber, yarn, cloth, etc. in the case of textiles. The substrate can be of the following types. E.g.
a) Natural
b) Synthetic
c) Regenerated
d) Inorganic
e) Mineral
2) The components of the dyeing process-Dye:
The dye is dissolved in the dye bath.
3) Environmental factors:
The surrounding conditions at dyeing depend on the following factors. E.g.
a) Solvent
b) pH
c) Temperature
d) Dyeing assistance
a) The components of the dyeing process-Solvent:
Dyeing is done through aqueous and water is its important solvent. Submerging all textile fibers in water generates a negative (-ve) charge on their surface. Hydrophobic fibers generate the most (- ve) charges (e.g., wool, cotton, silk). In this case, the dyeing process can be controlled using the pH and electrolyte of the dye bath. All these hydrophobic fibers can be easily dyed by highly soluble dyes such as direct, acid, etc. in water.
Weak hydrophobic fibers are usually ionic or nonionic by adjusting the dye bath. It can be dyed in any method. The aqueous medium of the dye helps to transfer the dye to the fiber. The transfer process is much easier when less water is used. This is because ionic dyes are more addictive to water than to fiber. So the rate of dye transfer in less water will be higher.
Again the water used in dyeing has to be heated. So the more water used, the higher the cost of dyeing. So dyeing on the water is both addictive and cost-dependent. The ratio of water and color used in dyeing is called the Liquor ratio. For example, 10 grams of fiber is dyed in 100 grams of liqueur, but its liqueur ratio will be 10:100 or 1:10.
b) pH:
The pH of the dye bath plays an important role in dyeing. Defective dyeing can occur if the pH of the dye bath is not correct. Such as layup taking dyeing, unleveled dyeing, etc.
c) Temperature:
Most dyeing processes are done at a temperature of 100°C or higher. High temperatures are required to accelerate dyeing. This is because the fiber swells through the water at higher temperatures. As a result fiber penetration is better.
d) Dyeing assistance:
It is not possible to dye in a dye bath only by controlling the pH and temperature. Therefore, adding some auxiliary chemicals such as electrolytes, leveling agents, carrier solvents, etc. to the bath accelerates the dyeing process and increases the dye addiction.
Things to consider in dyeing and dyeing process selection:
The following issues need to be considered in choosing a dye or dyeing process.
1) Hue
2) Shade
3) Brightness
4) Cost
1) The components of the dyeing process-Hue:
Hue means colors such as red, blue, yellow, etc. Hue is extremely important. The mixture of dyes is specially cared for to create the desired shade.
2) Shade:
Shade means the accumulation or concentration of color. The deeper the shade, the more dye will be present in the fiber. As a result, dyeing will be expensive. Also, the greater depth of the shade affects the fastness of the dyeing. For example, the light fastness of the dyed fabric increases with the depth of the shade. Again the washing fastness decreases as the depth of the shade increases.
The depth of the shade is expressed by the percentage of dye in each unit of mass fiber. For example, 2% shade means 100 grams of fiber has 2 grams of dye. 4% shade means 100 grams of fiber has 4 grams of dye.
3) Brightness:
Brightness means how bright an object is. Some dyes are inherently bright, such as basic dyes. Again some dyes produce very dull, e.g.-mordant.
4) Cost:
Cost is an important factor in choosing a dyeing method. Some dyes are relatively cheap, such as acid dyes, while some dyes are relatively expensive, such as VAT dyes. Adding a dyeing assistant to a dye bath also increases the cost.
