2. Processes used for preparation of
textiles can be classified as:
Batch
Semi-continuous
Continuous one
Semi continuous and continuous machinery
generally is used for textile fabrics.
Batch machines are available for fiber, yarn
as well as fabrics & garments.
3. Machines for Batch Process
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Pre-treatment is carried out mainly on the
following machines:
Kier
Winch
Jigger machines.
4. Kier
Kiers are cylindrical vessels especially
designed to carry out scouring of cotton in
rope form.
Kiers may be either open in which liquor boils
at atmospheric pressure or may be closed
when the liquor is boiled high temperature
and pressure.
Two types:
1. Vertical kier
2. Horizontal kier
5. Kier
The capacity of a kier is generally 2-3 tons
but may vary from 0.5 to 5 tons.
Made of stainless steel or cast-iron.
6. Main parts of kier
1.
2.
3.
4.
5.
Cylindrical vessel
Mixing tank(liquor prepared
according to recipe)
Multi tubular heat
exchanger(heating the
liquor)
Perforated false bottom
Circular tube(spray liquor
on fabric)
8. Jigger
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Jigger is one of the oldest fabric
processing machines.
Can be used for pre-treatment and dyeing
of textile fabrics.
It is used for processing of fabrics in open
width, tensioned form.
Jigger consists of a V-shaped trough.
9. Jigger
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Two steel or ebonite rollers are fitted above
the trough over which the fabric to be treated
is wound in roll form.
Fabric passes from one roller trough guide
rollers in the trough to the other roller.
Low ML ratio (1:3-1:7) .
The liquor in the trough may be heated by
steam pipe.
12. Winch
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It is another old processing equipment
which processes fabrics in rope form.
It is suitable for all those fabric which can
withstand creasing during rope form
processing.
One of the major differences a winch has
with a jigger is lower amount of tension
working on fabrics during processing.
13. Winch
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The M:L ratio in winches is high, generally
around 1:25.
Due to much lower lengthwise tension
imposed on the fabric, winches are better
suited for processing of delicate fabrics
like knits & woolens.
Winches can be used for desizing,
scouring, bleaching or even washing of
textile fabrics.
14. Continuous Preperation
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1.
2.
3.
Continuous ranges are used whenever large volume
of fabric are being processed. The fabric moves
continuously through stages and compartments
which provide the chemicals, time, temperature and
rinsing needed for cleaning the fabric.
Each stage contains 3 substations:
An applicator where the fabric is impregnated with
appropriate chemicals.
A holding station which provides reaction time and
temperature.
A washing station for flushing out the impurities.
16. Semi-continuous or continuous
machines
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Padding Mangle:
It is one of the most familiar machines for
use in dyeing, pre-treatment or finishing.
It is used for application of chemicals or
even dyes to the fabric in a uniform
manner in open width form.
This machine is used in continuous and
semi-continuous methods of chemical/
dye application to fabrics.
17. Padding mangle
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A padder consists of a trough and a pair of
cylindrical rubber bowls.
The fabric passes under a submerged roll in the
trough filled with the treatment bath and then
through squeeze rolls. This process is called
padding.
The size is generally 170-200 cm in length and
30-40 cm in diameter.
The pressure of the padders are 1.5 - 2 bar.
Two types.
19. J-box
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J-Box is one of the popular
machines generally used in
scouring of cotton fabrics.
J-box is essentially a J-letter
shaped stainless steel chute
with large fabrics holding
capacity.
The fabric is fed from one end
& taken out of the other (First
in first out) in contrast to a kier
where it is first in last out.
20. J-box
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The fabric after saturation with liquor is fed from
the top and taken out from the lower end.
Depending on fabric speed (150-300 m/min)
and the capacity (10,000 m) a residence time of
60-90 min may be provided.
Fabric may be heated at the entry to the J-box
and may retain the temperature due to insulation
inside the chamber. M:L ratio 1:1.
After coming out from the J-box, the fabric is
sent to a washer.
23. Steamer
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Alternately, after saturating the fabric with the
liquor, it may be sent to a steamer.
Steamer provides dwell time, moisture and
temperature.
The speed is about 60 m/min, temperature
100-110°C and residence time 30 sec to 5
min.
The J-boxes have large capacity but, in
steamers the capacity is much lower.
24. •
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A steamer is generally the combination of
roller section-conveyor-bed.
The impregnated fabric enters the roller
section where the fabric is exposed to
heat and moisture in open sheet form. It is
then plaited onto a conveyor-bed to
provide reaction time for the chemicals to
work before the fabric is washed.
26. Washing unit
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Washing is carried out in order to remove water
soluble impurities after the completion of wet
process. Since washing is done with water, the
impurities must be either water soluble or
emulsifiable.
After steamer/ J-box fabric flows through
washers.
Generally the liquor is stationary and the fabric
movement through the liquor provides some
mechanical agitation and liquor interchange.
27. •
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An open width washer is a simple box
containing series of rollers where the
lower rollers are submerged in the wash
water.
Can be divided into several compartments.
Squeezing rollers are placed between
them to remove excess liquor.
30. Mercerization
• Treatment of cellulosic materials with
higher concentrated alkali for short period
at lower temperature.
31. •
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Mercerization is carried out for the following
purpose:
Improving luster (silky look, in tension
mercerization only).
Improving tensile strength.
Improved dimensional stability.
Increasing uniformity of dyeing & improving
color yield (savings in dyestuff).
32. Changes occurred in mercerization
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Mercerization causes swelling in fiber.
Swelling causes Cross-section to become rounder, loss of
convolutions & detwisting leading to more lustrous surface.
Opening of fiber structure.
Increase in amorphous content due to decrystallization
Effect is observed at 18-24 % w/w NaOH solutions.
Higher no of –OH groups available as compared to un-
mercerized cotton.
Higher moisture regain, dye-uptake and reactivity
33.
34.
35. When Mercerization Can Be Carried Out?
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At Grey stage
After Desizing
After Scouring
After Scouring and bleaching
36. Application process
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Application of caustic soda solution
around at a Room temperature.
A dwell period of 55 sec on an average.
Tension at both directions.
Finally, washing-off of alkali from the
treated fabrics/ yarn.
37. •
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1. Impregnation of the material in in
relaxed state, cold caustic solution of
required strength and wettability.
2. Stretching while the material is still
impregnated in the caustic solution.
3. Washing off the caustic soda from the
material while keeping the material still in
the stretch state.
