Textile dyeing:
An introduction
Textile
dyeing is concerned with organic (that is, carbon-based) compounds that
can be dissolved in appropriate solvents, usually water. The dyes in solution
are absorbed on the surface of the textile fibre then pass into the interior
of the material by a process called diffusion.
The process of transferring the dye from solution to the fibre is called exhaustion, with 100% exhaustion meaning that there is no dye left in the dyebath solution. An important property of a dyeing is its levelness, in other words when the same depth of colour can be seen all over the material.
The process of transferring the dye from solution to the fibre is called exhaustion, with 100% exhaustion meaning that there is no dye left in the dyebath solution. An important property of a dyeing is its levelness, in other words when the same depth of colour can be seen all over the material.
Dye
molecules are attracted by physical forces at the molecular level to the
textile. The amount of this attraction is known as 'substantivity': the
higher the substantivity the greater the attraction of the dye for the
fibre.
Another
factor is good penetration, when the dye has penetrated deeply into the
structure of the fibre, colouring it from the outer surface of the fibre
to its interior.
Also See:
Dyes
and pigments: natural
Dyes
and pigments: synthetic
Fastness
tests
