2. Introduction:
Blending of two or more different types of
fibres is of crucial significance to the textile
industry. The yarns and fabrics produced
display a range of desirable properties that
otherwise could not be achieved by a single
textile component. The technical and
commercial requirements of blended fibres
place great demands on dyers and colorists to
achieve high-quality, reproducible results under
production conditions .Blends any textile
materials, a from fibres through yarns to
fabrics, which are deliberate combinations of
chemically or physically different fibrous
polymer
3. Types of Blends:
Fiber blends: Different fiber types
blended into a single yarn.
Combination fiber blends: (a) Yarns of
different fiber types woven, knitted, or
bonded into fabric.
(b) Single yarns composed of blended
fibres plied together.
4. Some Reasons for Blending of
fibers:
To facilitate processing
To improve properties
To produce multi-colored fabrics
To reduce cost, to increase cost
5. Factors affecting the choice of
dyeing methods:
* Colorist effect required (Union, reserve, tone-in-tone).
* Colorfastness required of the resultant dyeing.
* Suitability of the dyeing for subsequent finishing
processes.
* Compatibility of dyes from different application
categories with one another.
* Availability of particular types of batch, semi-continuous
and continuous dyeing equipment.
* Cost of the dyes and chemicals involved.
* Economics of the overall process.
6. Important factors in dyeing
blends:
* Dye selectivity
* Dye bath conditions
a. Dye auxiliaries
b. Dye bath temperature
c. Stress on fabric.
*Dyestuff blockage
a. Retarding agents
b. Dye-molecule blockage
*Determination of dyeing on various fibers:
a. Leach outs
b. Riders
7. Important considerations in
dyeing blends:
Singeing – Natural fibers vs. Synthetics.
Desiring – Sizes normally used can differ.
Scouring – Effects of detergent and alkali.
Bleaching –Choice of bleach adverse
effects of bleaching.
Mercerization – Castigation effects of
sodium hydroxide.
Heat setting- Effects of high temperature
dry or wet heat.
10. Dyeing Procedure For Polyester:
The dye bath is set with 1g/l-Dispersing agent
0.5g/liter-wetting agent/leveling agent. The redox
buffer is added and the PH is adjusted to 5.5. The
redox buffer is added and the PH is adjusted to
5.5. The liquor is circulated through the package at
50°c for 15 min. The dyes are dispersed in 10 to
20 times in the weight of water at 45-50°c. The
dispersion is filtered through a thin cloth into the
dye bath. The liquor is circulated and the
temperature raised to 130°c in 30 mins. Dyeing is
continued for 40-60 min.
11. Dyeing Procedure For Cotton:
The dye bath is set up with required
amount of dyes at relative
temperature. After 10 min, required
amount of salt is added. Raise the
temperature to 60°c. Dyeing is carried
out for 20 min.Then soda ash of
required quantity is added continue
the dyeing for 90 min and then after
treatment is given.
12. Conclusion :
We have learnt by this assignment how to
make Blended dyeing, its dyeing
procedure, recipe, factors affecting the
choice of dyeing methods etc. So, all the
reasons, it is very important for every
textile students and this knowledge will
be help in our future job life.
