4. SCOURING
Scouring is the process by which all natural and additive impurities
such as oil, wax, fat etc are removed to produce hydrophilic and clean
textile material.
5. Objects of scouring:
To make the fabric highly hydrophilic.
To remove impurities such as oils, waxes, gum, husks
as nearly as possible.
To increase absorbency of fabric or textile materials
without physical and
chemical damage.
To produce a clean material by adding alkali.
To make the fabric ready for next process.
To remove non-cellulosic substance in case of cotton.
6. The changes occurring
of cotton fabric during
scouring:
• Saponification oils and free fatty acids are converted into soaps.
• Pectins and pectoses are converted into soluble salts of pectic acid.
• Proteins are degraded to simple soluble amino acids or ammonia.
• Mineral matters are mostly dissolved.
• Additive dirts are removed.
• Non-saponifiable oils are emulsified by the soluble soaps generated form the saponifiable oils.
8. The type
of cotton
The color
of cotton
The
cleanliness
of cotton
The twist
and
count of
the yarn
The
construction
of the fabric
SCOURING PROCESS DEPENDS ON
10. Main Chemicals For Scouring
• >
• >
• >
• >
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• Chelating
agent
• Caustic Soda
• Sodium
silicate
• Soda ash
• Detergents
11. Kier boiling is a scouring process for cotton and linen in
which the fibers are treated for removal of impurities by
boiling with a 1% solution of caustic soda. Its main
purpose is to remove most of the natural impurities such
as wax, wood fragments and oil stains. Kier boiling
process of cotton is performed in a kier boiler and the
fabric is scoured in rope form by alkali liquor. Kier is a
large cylindrical iron vessel. The kier may be open one as
closed one and horizontal or vertical.
Kier Boiler
12. RECIPE
• Caustic soda (Strong) → 2- 5%
• Soda ash (mild) → 0.5 – 1.0%
• Sequestering agent → 0.2-0.5%
• Wetting agent + Detergent → 0.5-1.0%
• M : L → 1:5 to 1:7
• Temp → 100 ºC – 120 ºC
• Time → 12hrs – 8 hrs
14. In continuous process J-box is used for cotton scouring. It
looks like English letter j. so it is called J-box. In J-box
cotton is scoured open width and rope form.
J-Box
