Saturday, April 29, 2017

10 Important Terms and Definition of Dyeing

Dyeing is one of the most complicated branches of textile engineering. Numerous types of terms and definitions are frequently used in every operation of dyeing floor by dyeing engineers and technologists. If production related anybody don’t know specific terms of dyeing then whole process may break down. So there is no way to alternative knowing of dyeing terms and definitions. Besides, job interviews and various competitive examinations for textile engineers have to frequently ask different dyeing terms. In this article, I have given most essential 10 dyeing terms and glossary for my readers. I think you will enjoy it.
Dyeing operation
Fig: Dyeing operation
10 Important Terms and Definition of Dyeing:

1. Shade%:
Shade% means the depth of color. It is expressed as percentage (of dye amount in unit weight of fabric). Expressed as 1% owf (on the weight of fabric), 2%, 5% etc.

Scale of shade%:

  • Light shade = up to 0.5% owf
  • Medium shade = 0.6 – 1.5% owf
  • Dark/Deep shade = 1.6% and above.
2. Substantivity:
  • Natural attraction between dyes and fibres is termed as substantivity.
  • Color strike is the result of substantivity.
  • This influence the dye transfer from dye bath to textile materials without any chemical and auxiliaries.
3. Affinity:
  • Forced/Artificial attraction between dyes and fibers.
  • Dyeing is performed for this affinity of dyes and fibers.
  • It varies with the degree of catalysts.
4. Color strike:
  • Initial absorption of dyes due to substantivity is called the color strike.
  • At the starting of dyeing, the rate of transfer of dye from the dye solution to the textile materials is more than any other time.
  • After 30 seconds, 50% dyeing is completed.
5. Exhaustion:
  • Total amount of dyes absorbed by the fiber in a dye bath after the adsorption, sorption and desorption is completed.
  • It is expressed as E%.
6. Fixation:
  • Total amount of dyes finally fixed (after washing) with the fibers in a dyeing process. It is expressed by F%
  • F% = E% - (washing + soaping + other) loss.
7. Adsorption:
Dye molecule when in contract with fiber.

8. Sorption:
It is the state when dye molecules entered into the fiber.

9. Desorption:
In this state dye molecules come out from the fiber.

10. Anchoring forces:

The force by which dye molecules are fixed in fibers.