my presentation

1. Scouring
Scouring:
Desized textile materials till containing oil, fats,
and waxes which are removed by alkali or
detergent are called scouring.
Objectives of Scouring
• To remove natural and added oils, fat and wax are from
the textile materials.
• Improve hydrophilicity.
• Improve absorbency.
• Prepare for the next process.
• To get uniform bleaching result

2. Natural Impurities (10-15%) Added Impurities (0.5-2.0%)
Fats Paraffin Wax
Waxes Spinning Oils
Hemicellulose Knitting Oils
Pectins
Proteins
Mineral Matter

3. Flow Process of Scouring
The scouring procedure is
dependent on:
• The type of cotton which is
using
• Color of cotton
• Cleanliness of cotton
• The twist & count of the
cotton
• Construction of fabric

4. Actions in Cotton Scouring:
Actions involved in scouring
are
• Saponification
• Emulsification
• Detergency
i) Saponification is the name of the chemical reaction that
produces soap. In the process, animal or vegetable fat is
converted into soap (a fatty acid) and alcohol. The reaction
requires a solution of an alkali (e.g., sodium hydroxide or
potassium hydroxide) in water and also heat.
Saponification : It is the process in which fats are treated
with caustic which leads to the formation of hydrophilic
soaps.
ii) Emulsification : Waxes present in the fabric cannot be
removed in saponification. These are esters of higher fatty
alcohol and fatty acids. Similarly mineral oils, lubricants
cannot be converted to water soluble product by boiling with
caustic. Thus the scouring solution must also contain an
emulsifying agent.
iii) Detergency : After removal of fats by saponification and waxes by
emulsification, the remaining constituents, dust and dirt particles have
to be removed by a good detergent. Detergent not only removes the
dirt particles but also keep them in dispersed or suspended form in the
scouring solution and does not allow them to settle on other parts of
the fabric.

5. Chemicals and their purposes in
scouring:
• 1. Caustic soda (NaOH): Neutralizes acidic materials, saponify
glycerides (waxes and oils), solubilize silicates.
• 2. Sodium silicate: Penetrate and breakdown lignin in motes.
These penetrant’s are added, commonly, when fabrics have
large contents of motes and other assorted materials.
• 3. Wetting agent: Reduce surface tension and minimize
interfacial tensions.
• 4. Detergents: Emulsify fats, oils and waxes; remove oil borne
stains; suspend materials after they have been removed.
• 5. Chelating (sequestering agents): Deactivate metal ions.
• 6. Builder (salt): Cause detergents to become increasingly
effective.
• 7. Solvent: Assists emulsification by dissolving oily materials.

6. Method of scouring:
There are two types scouring method.
• 1.Continuous method (J box).
• 2.Dis continuous method (kier boiler).
Continuous method (J box method):
This method has four parts.
1.Saturation
2.Pre-heater
3.J-box
4.Washing unit.
Discontinuous process (kier boiling):
Generally, we use cotton in kier boiling process.
The fabric is scoured in a rope form by using alkali
solution.
Kier is a large cylindrical iron vessel.
This process may be open one as close one and
horizontal & vertical.
Open kier: It is not an air tight kier. This process
scouring temperature is 1000c. Process duration is
about 8-12 hours.
Closed kier: It is an air tight kier. It’s scouring
temperature is about (120-130)oc. Process duration is
6 hours.
Kier capacity: Kier capacity is about (200-5000) kg.
Generally, Standard capacity is 2000 kg.

7. Continuous method (J box).
• 1.Saturation: Saturation is a process that makes without using
caustic soda in the saturator. The saturator temperature is
about (70-80)0c. Saturation time will be 40-90 sec. Than the
fabric squeezed and passed into the next process (pre heater).
• 2.Pre heater: In pre heater, material has to pass into the
thermoplastic controlling system. The pre heater temperature
will be (110-120)0c. The method duration is only 30 second.
Then the fabric is prepared for the next process.
• 3.J Box: This is the main part of the process. In this process
caustic solution has to prepare where fabric has to store about
30 minutes. The J box temperature is 1000c.In the J-box,
caustic soda solution removes all the impurities. After that,
the fabric will have to pass to the washing out.
• 4.Washing unit: Some water soluble impurities or products
that are left on the material are removed by here. Firstly,
material has to wash in a hot water. Then in a cold water.
Finally, the fabric has to dye.

10. Continuous method (J box).
Advantages:
• Continuous process
• Less time consumes.
• Economically benefit able.
• Scouring, desizing can do at a time.
Disadvantages:
• The result is not good as kier boiler.
• Huge damage may occur due to power failure.

11. Discontinuous process (kier boiling):
• Generally, we use cotton in kier boiling process.
• The fabric is scoured in a rope form by using alkali solution.
• Kier is a large cylindrical iron vessel.
• This process may be open one as close one and horizontal
& vertical.
• Open kier: It is not an air tight kier. This process scouring
temperature is 1000c. Process duration is about 8-12 hours.
• Closed kier: It is an air tight kier. It’s scouring temperature
is about (120-130)oc. Process duration is 6 hours.
• Kier capacity: Kier capacity is about (200-5000) kg.
Generally, Standard capacity is 2000 kg.

12. • Kier boiler is provided 2 tubes. One is at the bottom in
addition to to a greater extent than or less other is top.
• There is 1 manhole for loading in addition to unloading of
sample.
• Preheater is besides provided at the middle of these 2
tubes.
• The liquor is prepared into the mixing tank past times to
a higher house chemicals in addition to so it brought into
the preheater in addition to heated past times the steam.
• The stuff is loaded inwards the machine past times
human being hole in addition to kept inwards rope form.
• Then the hot liquor is pumped in addition to sprayed past
times spader plate onto the stuff which is packed into the
kier.
• The temperature of the liquor is most 100 oC in addition
to boiling for 8 hrs. the excess liquor passes slow over the
packed cloth in addition to percolates through the faux
bottom of the kier.
• Then this excess liquor is collect at the bottom of the kier
in addition to pumped into the auxiliary heater past
times a centrifugal heart in addition to this cycle is repeat.
• Below the faux bottom the liquor is costless from the
oxygen of air.
• After scouring, the stuff is washed amongst H2O
otherwise impurities on the stuff would non last
removed.
• Then the stuff is neutralizing amongst 0.1%-0.055 acetic
acid. And in addition to so mutual depression
temperature wash.

13. Precaution:
• Kier should last clean.
• Material should last packed evenly.
• No air steal should last formed.
• The stuff should last immersed inwards liquor
completely.
• After boiling the liquor should last removed inwards
absence of water.
• Before starting, all the joining parts should last
checked.
• The articulation parts should last leak proof.
• Before scouring, the stuff should last starch free.

14. Advantages:
• Well scouring
• Remove most of the natural color.
Disadvantages:
• Failure of pressure gauge, boiler may be brunt.

15. Difference between J box and kier
boiler process

16. Solvent Scouring Process with
Advantages and Disadvantages
• Solvent scouring is the treatments of fabrics in
organic solvent medium to remove impurities
such as lubricating oils and spin finishes. Certain
organic solvents will readily dissolve oils fats and
waxes and these solvents can be used to purify
textiles.
• Removal of impurities by dissolution is called
Extraction. Basically solvent scouring is a
refinement of dry-cleaning and is carried out
either batchwise or continuously.

17. Suitable Solvents
• It is found that waxes are removed by solvents
like chloroform, benzene, carbon tetra
chloride etc.
• But those are not used industries because of
their high cost and toxicity. Now a days widely
used trichloro ethylene, perchloro ethylene
etc.

18. • Solvent is a liquid, solid, or gas that dissolves
another solid, liquid, or gaseous solute,
resulting in a solution Particularly for fabrics
which do not have to desize, polyester, nylon,
acetate, acrylic, and woolen goods Usually
chlorinated hydrocarbons, e.g. tetra chloro
ethylene, tri chloro ethylene and 1,1,1- tri
chloro ethane.

20. Bio-Scouring
• Enzymatic Scouring or Bio-Scouring can
simply be defined as the application of living
organisms and their components to remove
the natural and added impurities.
• It is not an industry in itself, but an important
technology that will have a large impact on
many industrial sectors in the future.

21. Enzymatic scouring
Enzyme :3 g/L or 0.5%
Sequestering agent : 1 g/L
Wetting agent : 2 g/L
Temperature : 60oC
Time : 30 min
M: L : 1:10
pH : 8 -9

22. Comparison of Bio-scouring and
Conventional Scouring:
Parameters Bioscouring Conventional scouring
pH value of process 8–9.5 13–14
Temperature 50–60 95–100
Residual pectin 10–15 10–15
Weight loss % <2.5 3–8
Hydrophilicity (TEGEWA) <2 s <2 s
Fibre damage (DP component) <0.05 <0.05
Degree of whiteness 5–10 points improved 1–2 points improved
Handle Very soft Harsh
Dyeability Good Good
Water saving 20–50%

23. Estimation of Scouring Effect
• Estimation of Scouring Effect by Weight Loss
and Absorbency Test. Scouring is the
pretreatment process by which oil, wax, fat are
removed from fabric. So that fabric weight will
be reduced slightly (in case of good souring
4%-8%) and absorbency of fabric will be higher
for removing of oil, wax, fat etc.

24. Estimation of Scouring Effect
Evaluation of the scouring efficiency is done by
the following methods:
1) Absorbency test
a)Drop test
b)Immersion test
c)Spot test
2)Weight loss method
3)Column test
A drop of water is placed on the surface of
the fabric and time to absorb the drop is
recorded. Faster the time(0.5 sec), means
more absorbent i.e scoured fabric. If drop is
not absorbed on the fabric means, fabric is
unscoured.
Weight loss test: Weight loss is 4-8% is normal.

25. UNIT III - BLEACHING AND
MERCERIZATION
• Objectives of bleaching,
• Introduction to bleaching agents like sodium
hypochlorite and hydrogen peroxide,
• bleaching of cotton, blends and synthetics.
• Bleaching of wool, silk,
• evaluation of efficiency of bleaching.
• Objectives of mercerization,
• Changes in cotton after mercerization,
• Study of machinery used for mercerization of yarn,
• woven and knit fabrics.
• Liquid ammonia treatment,
• Evaluation of mercerization efficiency using barium
activity number