Water is an inevitable part of textile and apparel processing industry .The textile fibers, including wool, silk and cotton is prepared for fabrication by scouring processes which involve the use of quantities of water. The standards of purity required are high in all cases but very with the specific operations.

1. Water for textile industry
MD.AZMERI LATIF BEG
M. Sc in Textile Engineering
Specialized in Apparel
Manufacturing, Processing and
Designing

2. The fresh water is rarely used directly for drinking
purposes, as the water gets contaminated with
impurities during its transportation to the city
reservoir. Even, the water which is to be used for
textile industrial process also needs a pretreatment.
For instance water for textile industry should not
contain too much of iron, as it causes staining of
fabric. Water for food industry cannot afford to have
manganese, as it causes staining of containers and
adversely affects the taste and quality of material
cooked in that water. The boiler feed water should not
contain excess of salts of calcium and magnesium, as
they consume more heat due to insulation of
containers and pipes by deposition of scales.

3. Water for textile industry
Water in textile industry: The textile fibers, including wool,
silk and cotton is prepared for fabrication by scouring
processes which involve the use of quantities of water. The
standards of purity required are high in all cases but very
with the specific operations.
Wool scouring- in wool scouring, all fresh water is added
in the third or final scouring tank from which the wool
emerges in its finished condition. Impurities in the water that
will have cling to the fiber therefore are obviously out of place
and will have the same deleterious effect in subsequent
processes as imperfect scouring. Suspended impurities are
clearly undesirable, organic matter being especially
deleterious. Therefore waters polluted by sewage or organic
industrial wastes and turbid waters are always purified before
use in scouring-tanks.

4. Water for textile industry
A second and even more important class of impurities
consists of those substances which unite with soaps used in
scouring to form insoluble soaps. These substances iron,
aluminum, calcium, and magnesium, destroy their equivalent
values of soap for detergent purposes thereby making
necessary the use of an excessive amount of soap. In
addition the insoluble soaps sticks closely to the fiber and
make efficient scouring very difficult. On this account they
are more detrimental to the process than inorganic
suspended matter composed largely of colloidal particles of
clay. Priest man states that water containing 30 English
degrees of hardness (428 parts per million of calcium
carbonate) cannot be used for satisfactory washing and
adopts 50 of hardness (71 parts per million of calcium
carbonate) as the limit of hardening constituents for a
satisfactory water supply.

5. Water for textile industry
In scouring by the two-stage process of steeping
and scouring, the importance of pure water is
even greater for in addition to the effect of
hardness in the scouring operation, the recovery
of potash from the steep water will be rendered
somewhat more expensive and the purity of the
product will be decreased by the saline
constituents of the water. In this case all mineral
impurities not merely the hardening constituents
have a deleterious effect.

6. Water for textile industry
In scouring by violate solvents and subsequent washing, since
no soaps used, purity of water is a minor consideration.
Suspended matter of course is undesirable. If the wash water is
utilized for the recovery of potash, all dissolved impurities will
cause scale in the evaporators and all will decrease the purity of
the potash produced. Each 100 parts per million of mineral
solids in the water will reduce the purity of the potash by
approximately 1 percent. If the wool is scoured by one of the
newer detergents such as the suffocated alcohol products like
lgepone6 then the hardness in the water will be of less
subsequence. This is due to the fact that the calcium and
magnesium compounds of these detergents are soluble, hence
do not because a loss of detergent power and more particularly
do not precipitate on and foul the surface of the wool.
Water used for rinsing the wool after scouring may amount to as
much as 100 gallons for each pound of wool scoured. This
water should be free from suspended matter, but otherwise
requires no special qualities.

7. Water for textile industry
Silk industry uses- in the silk industry pure
waters are required, as in wool scouring, to conserve
soap and prevent contamination from sticky
precipitates.
In the first stage of silk manufacturing, the raw silk is
soaked in a strong solution of soap containing meat’s
foot oil. This process is necessary to give the silk
operation. With water containing lime and magnesium in
large amounts, the soap forms a characteristic curd
precipitate which mats the fiber and causes
considerable difficulty in winding the silk. Furthermore,
the precipitate clings to the fibers, forming soap specks
which later harden the silk at these points.

8. Water for textile industry
The next operation that of boiling off requires the use of
greater quantities if both soap and water. The deleterious
results of unsuitable water here are. Therefore intensified
where lime spots form, the silk may become discolored
and the fiber will crack.
Weighting is largely affected by the lime and magnesium
content of the water used in previous operations. Lime
spots prevent the absorption of the tin solution at such
points, since the fiber is there covered by the sticky lime
precipitate. The result is lack of uniformity in weighting and
hungry spots which later in the dyeing operation produce
uneven coloring of the fabric.
Brighter colors are said to be produced with soft waters,
using less dye, than with other water containing large
amounts of the alkali-earth elements.

9. Water for textile industry
Cotton industry uses – the cotton industry has
long recognized the value of soft water in its operations. The
boiling-off requires the use of resin soap in large amounts,
which soap, like others, is waste fully consumed by calcium
and magnesium in the water. The precipitates formed are
resonates of calcium and magnesium, which are just as
troublesome in later operations as the corresponding oblates
and starts. Spots, difficult to wash out, dye and bleach are
formed and a uniform white, so essential in this industry, is
almost impossible to obtain. It is characteristic of silks and
coattails produced by plants using soft water that the fabric
has a softer feel not at all like the harsh feel of fabrics
produced with waters containing large amounts of the
hardening constituents. In the manufacture of textiles
therefore, the necessity for a clear colorless water containing
as little calcium and magnesium as possible is obvious
unless newer detergent are use.

10. Water for textile industry
Rayon industries- in the rayon industry as in
the case of natural fiber the water must be high purity to
give best results. Water must be soft because lime and
magnesium salts which are responsible for hardness of
water also cause hardness of finish on rayon and
interfere with the level dyeing. Traces of iron in the
water may be highly detrimental as evidenced in a rayon
plant operating on the Niagara River. In this plant
splotchy discolorations were noted in the product and
after much effort, were finally traced to the presence of
less than 0.5p.p.m. of iron in the wash water. When this
was removed by suitable treatment the difficulty cleared
up.

11. Water for textile industry
Water for dyeing and bleaching- involving as it does
the use of such small amounts of chemicals and large
amounts of water to produce delicate coloring effects,
the dyeing of fabrics often presents chemical problems
of considerable difficulties. The solution of these
problems often hinges on the proper choice or treatment
of water used in the process. Water containing large
amounts of calcium is unsuitable and even ruinous for
use in dyeing with aniline colors, but is essential to the
successful use of logwood or weld, dyed on a mordant
of iron or aluminum.

12. Water for dyeing and bleaching
Calcium and magnesium act very much alike in
dyeing. Some of the effects of these constituents
are as follows: Heavy tar like precipitates from
when such aniline colors as methyl violet,
malachite green, magenta and safranine are
dissolved in waters high in calcium and
magnesium. This tar like precipitate sticks to the
fiber and results in uneven dyeing, poor shades
and that annoying defects of rubbing off.
Magenta and safranine are peculiarly susceptible
to the influence of these constituents, the effect
being noticeable in changes in both color and
intensity of the coloring material. Color is wasted
and flat shades are produced in dyeing with
Turkey red or cochineal scarlet.

13. Water for dyeing and bleaching
On the other hand in dyeing with alizarin it is
necessary to have calcium carbonate present to
cause complete saturation of the mordents, but
when calcium and bicarbonate radicals are
present, carbonic acid is freed, calcium carbonate
is precipitated by the heat and the bath takes a
violet color due to the formation of a compound of
calcium and alizarin. If the solution is boiled the
lime lake deposits as a violet powder and the bath
cannot be used. Thus it can be seen that calcium
may be helpful or detrimental to dyeing according
to circumstances, but as a rule calcium and
magnesium salts result in UT1 even dyeing, fading
colors, spotted effects, off-shades, and a waste of
color.

14. Water for dyeing and bleaching
Iron is very objectionable impurity. Dull and flat colors
are frequently caused by this constituent especially
when dyeing on a mordant. If water contains iron in
any appreciable amounts, it is practically useless for
dyeing or printing with alizarin or for any of the coal-
tar colors that are fixed on a tannin mordant. Also in
bleaching iron is a troublesome constituent. The iron
is oxidized bleach solutions causing yellow, brown or
muddy white effects. This difficulty can be partially
remedied by acid treatment, but there is then danger
of injuring the fabric. Lau8ndries have much the same
difficulty with ferruginous waters. It is therefore
evident that a water suitable for dyeing and bleaching
should be free suspended matter, low content of iron
as soon as possible.

15. Water for Apparel washing, processing and finishing
 In apparel washing, processing, dyeing and finishing
need water. Water is an inevitable part of textile and
apparel processing industry Water for a textile plant
may come from various sources. But this water can
not be used directly in textile processing because it
contains various salts. These salts are mainly the
carbonates (CO3
2-), Hydrogen carbonates or bi-
carbonates (HCO3
-), Sulphates (SO4
2-) and Chlorides
(Cl-) of Calcium (Ca2+), and Magnesium (Mg2+). These
are called hardness in the water. These must be
removed though water treatment plant. An study said
that need 170 liter water to process a knit fabric.
Apparel finishing is the last part of a end product so
water must be purified before using.
