Dyeing is an ancient art which predates written records.
It was practiced during the Bronze age in Europe.
Primitive dyeing techniques included sticking plants to
fabric or rubbing crushed pigments into cloth. The
methods became more sophisticated with time and
techniques using natural dyes from crushed fruits,
berries and other plants, which were boiled into the
fabric and gave light and water fastness (resistance),
were developed. Dyeing can be done at any stage of the
manufacturing of textile- fiber, yarn, fabric or a
finished textile product including garments and apparels.
The property of color fastness depends upon two factors-
selection of proper dye according to the textile material
to be dyed and selection of the method for dyeing the
fiber, yarn or fabric. A process of coloring fibers,
yarns, or fabrics with either natural or synthetic dyes.
Substances that add color to textiles. They are
incorporated into the fiber by chemical reaction,
absorption, or dispersion. Dyes differ in their
resistance to sunlight, perspiration, washing, gas,
alkalies, and other agents; their affinity for different
fibers; their reaction to cleaning agents and methods;
and their solubility and method of application.
and types are listed below:
A class of dyes used on wool, other animal fibers, and
some manufactured fibers. Acid dyes are seldom used on
cotton or linen since this process requires a mordant.
Acid dyes are widely used on nylon when high wash
fastness is required. In some cases, even higher wash
fastness can be obtained by after treatment with
Direct Printing, it is the most common approach to apply
a color pattern onto a fabric. If done on colored fabric,
it is known as overprinting. The desired pattern is
produced by pressing dye on the fabric in a paste form.
To prepare the print paste, a thickening agent is added
to a limited amount of water and dye is dissolved in it.
Earlier starch was preferred as a thickening agent for
printing. Nowadays gums or alginates derived from seaweed
are preferred as they allow better penetration of color
and are easier to wash out. Most pigment printing is done
without thickeners because the mixing up of resins,
solvents and water produces thickening anyway.
Basic (Cationic) Dyes
Basic dyes are water-soluble and are mainly used to dye
acrylic fibers. They are mostly used with a mordant. A
mordant is a chemical agent which is used to set dyes on
fabrics by forming an insoluble compound with the dye.
With mordant, basic dyes are used for cotton, linen,
acetate, nylon, polyesters, acrylics and modacrylics.
Other than acrylic, basic dyes are not very suitable for
any other fiber as they are not fast to light, washing or
perspiration. Thus, they are generally used for giving an
after treatment to the fabrics that have already been
dyed with acid dyes.