Textile Engineering

1. Blendomat :
Working principle of BDT: In this zone, basic function is to open the fiber from
the bale where fibers are at very compressed and disoriented state. The opening
device has to penetrate into the bale and pick up the tuft of fiber during releasing
from different bales simultaneously. The size of fiber package is converted from
200 kg to 10 gm/tuft in this zone. The machine moves to cover maximum bales.
Generally roller with toothed disc is used for opening device. No beating action
but picking is performed here.
As shown in figure, rotating opening rollers fitted with toothed discs are made to
traverse a line of preassembled cotton bales, the toothed discs plucking tufts
from each bale as they move from bale to bale. The toothed discs give a gentle
opening to prevent or minimize the fiber breakage while producing smaller tuft
sizes at higher production rates than the mixing bale opener.
Technical data:
Traverse speed : 10~18 m/min
Speed of take-off roller : 1400~1800 rpm
Nominal take–off depth : 2.5~3.5 mm

2. CL-C3 :
Working principle of CL-C3:In this zone, basic function is to open the
fiber tuft to smallest size and to clean the tuft to the greater extent
removing even smallest size of trash and dust which are trapped
between fibers.
The system comprises 3 rotating beaters with carding saw tooth wire
projecting from its surface with different gradual point density and a
series of grid bars positioned below the beater. The system is used as a
last opening and cleaning stage for cotton tufts in the blow room and
therefore receives tufts from the coarse cleaner and opener.
Importantly, the beater speed should progressively increase from
beater 1 to 3 (for example 900, 1100, 1400 rpm). Hence, the mean tuft
size is decreased from 1 mg by the first beater to 0.7 mg, 0.5 mg by the
second and third beater.

3. Cleaning Efficiency: Cleaning efficiency of the machine is the ratio of the trash
removed by the machine to that of total trash fed to the machine, expressed as
percentage.
Cleaning efficiency
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=
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Let,
Total wt. of fiber in a lay down = 20,000 kg (100 bales)
Trash = 4% of total wt. = 800 kg
Trash removed = 2.8 % of total wt. = 560 kg
So, cleaning efficiency will be 70 % according to the formula.
Basic parameters to be considered in blow room:
1. No. of opening machine
2. Types of beater
3. Beater speed
4. Production rate of individual machine
5. Fiber micronaire
6. Size of the flocks in the feed
7. Type of grid and grid setting
8. Position of the machine in the sequence
9. Amount of trash in the material
10.Temperature and relative humidity in the blow room

4. Spinning Technology - 1
Flow chart of carded yarn production:
Input Machine Output
Bale Blow Room Card mat
Card mat Carding Card sliver
Card sliver Breaker draw frame Drawn sliver
Drawn sliver Finisher draw frame Drawn sliver
Drawn sliver Simplex Roving
Roving Ring Yarn
Flow chart of combed yarn production:
Input Machine Output
Bale Blow Room Card mat
Card mat Carding Card sliver
Card sliver Breaker draw frame Drawn sliver
Drawn sliver Lap former Lap
Lap Comber Combed sliver
Combed sliver Finisher draw frame Drawn sliver
Drawn sliver Simplex Roving
Roving Ring Yarn
Properties of cotton fibers considered by cotton spinners:
1. Fiber fineness: Fiber fineness is measured in Micronaire value (MIC). The
higher the micronaire value of fiber the coarser the fiber.
Rating of MIC value-
MIC Description
Less than 3.0 Very fine
3.0~3.6 Fine
3.7~4.7 Medium
4.8~5.4 Coarse

5. 5.5 to above Very coarse
Fiber fineness influences the number of fibers in the cross section of yarn.
The finer the fiber the higher the number of fiber in yarn cross section.
2. Maturity: The maturity of cotton is defined in terms of the development of
cell wall. A fully mature fiber has a well developed thick cell wall. On the
other hand, an immature fiber has a very thin cell wall.
Moisture ratio =
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If, M.R. = 0.85, good fiber
M.R.= 0.75, average fiber
M.R = 0.65, poor fiber
Immature fiber leads to :
- Nepping
- Loss of yarn strength
- Varying dye ability
- High proportion of short fibers
3. Fiber length: The average length of spinnable fiber is called staple length.
The quality, count, strength etc. depend on the staple length of fiber.
Normally the higher the staple length of fiber the higher the yarn quality.
Staple length Category
1” or less Short staple
1
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” to 1
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” Medium staple
1
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” to 1
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” Long staple
4. Fiber strength: The higher the fiber strength the higher the yarn and fabric
strength. Very weak cottons tend to rupture during processing both in blow
room and carding, creating short fibers and consequently deteriorate yarn
strength and uniformity. Minimum strength for a textile fiber is
approximately 6 CN/tex.
Some significant breaking strength of fibers are:
Polyester : 35~60 CN/tex
Cotton : 15~40 CN/tex

6. Wool : 12~18 CN/tex
5. Fiber cleanness: In addition to usable fibers, cotton stock contain foreign
matter of various kinds:
Vegetable matter- Husk portions, seed fragments, stem fragments, leaf
fragments wood fragments.
Mineral material- sand, dust, coal.
Other foreign matters- metal fragments cloth fragments, packing materials.
Accepted the range of foreign materials to the bale:
Up to 1.2% - Very clean
1.2% to 2.0% - clean
2.0% to 4.0% - Medium
4.0% to 7.0% - Dirty
7.0% to above - very dirty
According to the international committee for cotton testing methods the
following types are to be distinguished:
Trash - above 500 µm
Dust - (50~500)µm
Micro dust - (15~50)µm
Breathable - below 15 µm
6. Fiber color: color is particularly important as a measure of how well a yarn
or fabric will dye or bleach. Instrumental techniques for determining the
color of the sample have only now reached the industry, HVI measurement
of color provides reasonably accurate results of average reflectance and
yellowness in a sample.
7. Fiber elongation: Elongation is specified as a percentage of the starting
length. The greater crease-resistance of wool compared with cotton arises

7. for example from the difference in their elongations, cotton-6~10%, wool-25~45%.
contribution of fiber properties to yarn quality.
Mixing and Blending
Mixing: If different grade of same fibers are kept together, then it is called mixing.
Example: 50% of 4 Mic cotton + 50% of 5 Mic cotton.
Blending: When different fibers of same or different grades are kept together,
then it is called blending.
Example: PC, CVC. (polyester- cotton blend).
Objects of mixing and blending:
1. To achieve uniform quality
2. To improve processing performance
3. To reduce and control of production cost
4. To meet function and end used requirement
5. Aesthetic, (fashion, texture, luster).
6. To give the required characteristics to the end product.
strength
25%
fineness
14%
elongation
5%trash
6%
others
20%
length
12%
length
uniformity
18%

8. MX-U :
Working principle of MX-U: In this zone, main function is to blend the raw
material of different quality to equalize and even the mean quality of delivered
material. Because natural fiber generally remains in variation in quality.
The system employed in this zone as shown in fig. comprises six vertical chamber
in sequence. The technology of outlet is implemented in such a way that material
is taken up by rotating rollers evenly from every chamber and delivered after
mixing. Therefore, mixing takes place homogeneously at the inflow and outflow
position.
Technical data:
Storage volume per chamber : 1.4~2.6 ? ?
Storage capacity per chamber : 40~80 kg
Speed of opening roller : 1000~1200 rpm

9. CL-P:
Working principle of CL-P: In this zone, basic function is to open the fiber
tuft to smaller size and to clean the tuft removing big size of trash but smaller size
of impurities which are trapped between fibers is not removed here. Gentle
beating action but no picking is performed here.
The system comprises two rotating beaters with rods or flexible pins projecting
from its surface and a series of grid bars positioned below the beater. The system
is used as a first cleaning stage for cotton tufts with high trash content and
therefore receives tufts from the automatic bale opener.
The large tufts which cannot get lost through the grid system, follow a spiral path
around the beater to the outlet and make contact with the projections (pins) on
the rotating beater surface several times. The tufts are then struck against the
grid bars to eject coarse trash particles.
Technical data:
Diameter of beater: 700~800 mm

10. Speed of beater: 400~800 rpm
Grid bar setting: 2.5~3.5 mm
SP-FP :
Working Principle of SP-FP:The black arrow indicates the direction of the
fiber mass flow as shown in figure. The 3 CCD camera that give high but uniform
illumination with two fields. The cameras detect the distorted colors or contrasts
generated by the polarization in light polypropylene and transparent or semi-
transparent PE foils. On detection of a contaminated part of the fiber mass, a
combination of a compressed air nozzle beam and speed sensor are selectively
activated to blow the contaminated part of the fiber mass from the fiber channel
into a waste suction unit. Therefore, the fiber mass is screened to be free of
material contaminants