Cotton fiber carding is a crucial process in the textile industry,
responsible for preparing raw cotton fibers for spinning. The carding
machine plays a pivotal role in this process, effectively disentangling,
cleaning, and aligning the fibers to produce a uniform sliver suitable for
further processing.
Objectives Of Carding Machine
Opening and cleaning: The carding machine separates the fibers from
each other, removing impurities like dust, seeds, and leaf fragments.
This process ensures that only clean, high-quality fibers are used for
yarn production.
Individualization of fibers: The carding machine separates the fibers
into individual units, ensuring that they are evenly distributed and
aligned. This process is essential for producing smooth, strong
yarns.
Parallelization of fibers: The carding machine aligns the fibers in a
parallel orientation, which makes them easier to spin into yarn. This
process also improves the strength and uniformity of the yarn.
Removal of neps: Neps are small tangled clusters of fibers that can
cause problems during spinning. The carding machine effectively
removes neps, ensuring that the fibers are smooth and free from
defects.
Blending of fibers: When different types of fibers are blended
together, the carding machine ensures that they are evenly mixed. This
process is important for creating yarns with desired properties.
Formation of sliver: The carding machine combines the individual
fibers into a continuous strand called a sliver. The sliver is then
fed into subsequent stages of the yarn spinning process.
Parts Of Carding Machine
The primary components of a cotton fiber carding machine include:
Main Cylinder: A large, rotating cylinder covered with fine wires,
responsible for the primary carding action.
Flats: Stationary bars positioned close to the main cylinder, also
covered with fine wires, further enhancing the carding process.
Taker-in: A rotating cylinder with inclined teeth that grasps the
cotton fibers from the feed roller and transfers them to the main
cylinder.
Feed Roller: A rotating roller that regulates the supply of cotton
fibers to the taker-in.
Doffer: A rotating cylinder with finer wires than the main cylinder,
responsible for removing the carded fibers from the main
cylinder.
Licker-in: A rotating cylinder with sharp teeth that cleans the main
cylinder and doffer surfaces.
Coiler: A mechanism that collects the carded fibers into a continuous
sliver.
Carding Cylinder: A large rotating cylinder covered with fine wires
that entangle and align the cotton fibers.
Flats: Stationary bars positioned close to the carding cylinder, also
covered with fine wires, further enhancing the carding process.
Licker-in: A rotating cylinder with sharp teeth that cleans the
carding cylinder and flats surfaces.
Cylinder Cover: A cover that encloses the carding cylinder and flats
to prevent the escape of fibers.
Carding Zone: The area where the carding process takes place, formed
by the close proximity of the carding cylinder and flats.
Functions Of Carding Machine
Opening to individual fibers:
The blow room only opens the raw material to flocks, while the carding
must open it to the stage of individual fibers. This is essential to
enable elimination of impurities and performance of the other
operations.
Elimination of impurities:
Elimination of foreign matter occurs mainly in the zone of taker in and
cylinder. The degree of cleaning achieved by the modern card is very high.
Card sliver still contains 0.05 – 0.3% foreign matter.
Neps removal:
While the number of neps increases from machine to machine in the blow
room, the carding reduces the neps by carding action. Actually neps are
not eliminated at the carding, they are mostly opened out.
Elimination of short fibers:
Elimination of short fibers in the carding must be viewed in proportion,
actually very small, the less than 1% short fibers.
Sliver formation:
To deposit fiber material, to transport it and process it further an
appropriate product must be formed. This is the sliver.
Carding Machine Working Principle/Carding Machine Process/Function Of
Cylinder In Carding Machine
Stage 1: Feed roller-taker in zone
The card mat is pushed into the working zone of the feed roller-taker
in.
The card mat is opened to tufts by the taker in wire through combing
action.
Stage 2: Taker in-cylinder zone
From the feed roller-taker in zone, the opened tufts are transferred
to the taker in-cylinder working zone for opening to small tuft
size.
For cleaning, the material is passed over grid equipment and mote
knife attached the underside of taker in. Here points are in face to
back arrangement.
Suction ducts carry away the waste from trash box.
Stage 3: Cylinder-Flat zone
The small tufts are then transferred to cylinder-flat zone and opened
up into individual fiber which is defined as the actual carding
process.
Here points are in face to face arrangement.
Neps are removed in this zone.
The flats comprise 80-116 individual carding bars combined into a
belt moving on an endless path and approx. 30-50 flats are active to
the main cylinder. The rest are on the return run.
During this return, a cleaning unit strips fibers, neps and foreign
matter from the flat bars.
Stage 4: Cylinder-doffer zone
After the carding operation, the cylinder carries along the fibers
that are opened to single and loose condition as well as lie parallel
without continuous structure.
For the purpose of forming a continuous structure of the carded
single fibers the doffer is required.
The doffer combines the fibers into a web.
Here points are in face to face arrangement.
Carding Machine Actions
Combing Action:
Purpose: Opens and cleans fibers
Surfaces involved: Feed roller and taker-in
Wire direction: Same
Speed direction: Same
Wire arrangement: Face to back
Stripping Action:
Purpose: Opens and cleans fibers
Surfaces involved: Taker-in and cylinder
Wire direction: Same
Speed direction: Opposite
Wire arrangement: Face to back
Carding Action:
Purpose: Opens fibers to individual fibers and removes neps
Surfaces involved: Cylinder and flat
Wire direction: Opposite
Speed direction: Opposite
Wire arrangement: Face to face
Doffing Action:
Purpose: Forms a web of fibers
Surfaces involved: Cylinder and doffer
Wire direction: Opposite
Speed direction: Opposite
Wire arrangement: Face to face
These four actions work together to transform raw cotton fibers into a
uniform, clean, and aligned sliver suitable for spinning into yarn.
Read Also:
Cotton Fiber Carding Machine Passage/Schematic Diagram
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| Cotton Fiber Carding Machine Passage Diagram |
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| Cotton Fiber Carding Machine Schematic Diagram |
The central element is the carding cylinder, a large rotating cylinder
covered with fine wires. Surrounding the carding cylinder are stationary
bars called flats, also covered with fine wires. These flats are
positioned close to the cylinder, forming the carding zone where the
fibers are disentangled and aligned.
The taker-in, a smaller rotating cylinder with inclined teeth, is located
near the feed roller. The feed roller, another rotating cylinder,
regulates the supply of cotton fibers to the taker-in. The taker-in grasps
small tufts of fibers and transfers them to the carding cylinder,
initiating the carding process.
As the fibers travel along the carding cylinder, they are subjected to
the combing action of the fine wires. The wires on the cylinder and flats
interlock, separating and aligning the fibers. The doffer, another
rotating cylinder with finer wires than the main cylinder, removes the
carded fibers from the main cylinder.
The carding cylinder and doffer are both enclosed by covers to prevent
the escape of fibers. The licker-in, a rotating cylinder with sharp teeth,
is positioned close to the main cylinder and doffer. The licker-in cleans
the surfaces of these cylinders, ensuring efficient carding.
Finally, the coiler collects the carded fibers into a continuous sliver,
which is then ready for further processing in the textile manufacturing
process.
Carding Machine Specifications
Carding machine specifications vary depending on the specific machine
model and
manufacturer, but some general specifications include:
Working width: 1800mm, 2000mm, 2200mm, 2500mm
Capacity: 150kg/h, 200kg/h, 300kg/h
Cylinder diameter: 1230mm
Speed: 20 – 50m/min
Power consumption: 7 kW
Machine type: Automatic
Body material: Mild steel
Cylinder wire point density: 550-650 per inch
Doffer wire point density: 650-800 per inch
Licker-in wire point density: 1000-1200 per inch
Cylinder surface speed: 1000ft/min
Doffer surface speed: 1200ft/min
Licker-in surface speed: 1500ft/min
Additional features:
Anti-metal protection device
Frequency inverter control
Automatic stop motion
Dust collection system
Carding Machine Gauge Setting
Carding machine gauge setting is the distance between the carding
cylinder and the flat. This setting is critical for the quality of the
carded sliver. If the gauge is too close, the fibers will be damaged and
the card will be choked. If the gauge is too wide, the fibers will not be
carded properly and impurities will remain in the sliver.
Here is a standard carding machine gauge settings for different types of
cotton:
Short-staple cotton ______0.15-0.20 (mm)
Medium-staple cotton______0.20-0.25 (mm)
Long-staple cotton______0.25-0.30 (mm)
General Faults In Carding Machine
Carding is a crucial process in the textile industry, responsible for
preparing raw cotton fibers for spinning. The carding machine plays a
pivotal role in this process, effectively disentangling, cleaning, and
aligning the fibers to produce a uniform sliver suitable for further
processing.
1. Lower NRE%
Nep removal efficiency (NRE%) is a measure of the carding machine’s
ability to remove neps, which are small tangled clusters of fibers. Lower
NRE% indicates that more neps are present in the card sliver, which can
lead to problems in subsequent spinning processes.
Causes of Lower NRE%
Improper setting between different card surfaces
Incorrect point density of carding wire
Damaged carding wire
Improper geometry of card cloth
Incorrect speed setting of different carding surfaces
2. Higher Sliver CVm%
Sliver coefficient of variation (CVm%) is a measure of the variation in
sliver mass per unit length. Higher sliver CVm% indicates that the sliver
is uneven, which can lead to problems in subsequent spinning
processes.
Causes of Higher Sliver CVm%
Malfunctioning of card autoleveller
3. Sliver Breakage
Sliver breakage can occur due to disruptions in material inflow or
incorrect calendar roller pressure.
Causes of Sliver Breakage
Disruption in material inflow
Incorrect calendar roller pressure
4. Poor Web Structure
Poor web structure can be caused by damaged doffer wire or improper
stripping roller function.
Causes of Poor Web Structure
Damaged doffer wire
Improper stripping roller function
5. Out of Levelling Limit
If the control limit of leveling is exceeded, the machine stops. This can
be caused by disruptions in material inflow from the blow room or jamming
in the chute device.
Causes of Out of Levelling Limit
Disruptions in material inflow from blow room
Jamming in chute device
6. Roller Lapping
Roller lapping can occur due to improper working ambient conditions (RH%,
temp.).
Causes of Roller Lapping
Improper working ambient conditions (RH%, temp.)