4. Outline
Introduction
Key sources of water
Types of water
Water consumption in textile wet processing
industry
Problem create by hard water
Standard quality of soft water for dye house
5. Water resources are sources of water that
are useful .Uses of water
include agricultural
,industrial, household, recreational and env
ironmental activities. The majority of
human uses require fresh water.
98 % of the water on the Earth is salt water
and only three percent is fresh water;
slightly over two thirds of this is frozen
. The remaining unfrozen freshwater is
found mainly as groundwater.Water Is the
life –line of textile industry
Introduction
6. Key sources of water
Surface water
Ground water
Frozen water
Desalination
7. Types of water
Hard Water:
Hardness is defined as the the presence of sulphates,
carbonets and bi-carbonets of calcium, magnesium and
ferrous salts make hard water.
Soft water:
Water containing little or no dissolved salts of calcium or
magnesium, especially water containing less than about
85 P.P.M(parts per million) of calcium carbonate.
8. Types of water hardness:
Temporary hardness: The presence of calcium(Ca),magnesium(Mg)
and Iron(Fe) makes the water temporary hard.
Temporary hardness can be removed easily by boiling the water.
Permanent hardness: When water contains soluble salts of calcium
and magnesium such as their sulphates and chlorides.
Permanent hardness can’t be removed by boiling.
9. Water Consumption in Textile Processing
Industry
Water is used widely throughout textile processing operations. Almost
all dyes, specialty chemicals, and finishing chemicals are applied to
textile substrates from water baths. In addition, most fabric preparation
steps, including
desizing
scouring
Bleaching and
mercerizing
The amount of water used varies widely in the industry, depending on
specific processes operated at the mill, equipment used.
10. Hard water can create so many problems during wet
processing from desizing to finishing in textile mills.
Since every process is related to the next process, so all processes
should be done exactly to get best result or best quality product.
To do it first we have to know what problems hard water can
create in different stage of wet processing.
11. In Boiler:
If hard water is used in boiler, then a layer is
formed on the inner surface of the vessel. This
layer is very hard just like as stone which is not
removed without hammer or chesser or tessel.
This is called scale. In boiler, temporary hard
water produce CaCO3 & Mg(OH)2, the
combination of CaCO3 & Mg(OH)2 is called
scale
Desizing: Hard water de-active enzymes & insolubilize size materials
such as starch, PVA etc.
Problem create by hard water
12. Scouring: Hard react with soap during scouring. Soap is the Na & K salt of
higher fatty acid (C17H35COONa). The Ca & Mg salt of hard water react
with soap and produce insoluble organic salts which becomes the wastage of
soap.
CaSO4 + 2 C17H35COONa --> (C17H35COO)2Ca + Na2SO4
Insoluble organic salt
Bleaching: Hard water decompose bleach bath.H2O2 --> H2O + [O]
Mercerizing: It forms insoluble metal acid, reduce absorbency and luster.
Problem create by hard water
13. Dyeing: Ca2+ and Mg2+ ions of hard water react
with dye molecules and precipitated the dye. As a
result dyestuff are spoilt. Hence, uneven shade
(depth of dyeing) of color is produced.
Printing: It break the emulsion, change it’s
thickness and efficiency and it is also harmful for
thickener. Hard water cause problems in printing
process like dyeing.
Problem create by hard water
Uneven shade
14. From above, we saw that hard water causes problems in every process
of wet processing. So, we have to use such water that is suitable for wet
processing and don’t create any problem. Ideal quality of feed water for
textile industry is :
Finishing: Hard water interfere with catalysts, cause resins and other
additives to become non reactive, break emulsion and deactives soap
Problem create by hard water
15. •pH should be in the range of 7 – 8.
•Water should be odorless & colorless.
•Water hardness : maximum 5° dH.
•Solid content : < 50 mg/L.
•Dissolved solids : < 1 mg/L.
•Inorganic salts : < 500 mg/L.
•Organic salts : < 20 mg/L.
•Iron (Fe) : < 0.1 mg/L.
•Mn : < 0.02 mg/L.
•Cu : < 0.005 mg/L.
•Nitrate : < 50 mg/L.
•Nitrite : < 5 mg/L.
Standard quality of soft water for dye house
