Carding

Carding is a process used in textile production to separate individual fibers and prepare them for spinning into yarn. During carding, the fibers are passed through a series of wire teeth or rollers that separate and align them, causing many of the fibers to lie parallel to one another. This creates a more uniform and consistent fiber blend that is easier to spin into yarn. The carding process also removes most of the remaining impurities, such as dirt, seeds, and other debris, from the fibers. After carding, the fibers are usually spun into yarn and then used for various textile products such as clothing, blankets, and carpets.

Objects of Carding Process in Spinning:
Some important purposes of the spinning process have been pointed out below:

  1. Opening into independent fibres,
  2. Extracting of neps
  3. Removal of short fibre
  4. Blending of fibre
  5. Fibre orientation
  6. Formation of sliver

Here’s an explanation of the objectives of the carding process in spinning:

  1. Opening into independent fibers: One of the primary objectives of the carding process is to open up the fibers and separate them from each other. This makes it easier to remove any impurities and prepare the fibers for further processing.
  2. Extracting of neps: Carding also helps to remove any neps or small knots of fiber that may be present in the raw material. This is important because neps can affect the quality of the yarn and cause it to break during spinning.
  3. Removal of short fiber: Short fibers can also impact the quality of the yarn, so the carding process is designed to remove them. This is achieved by passing the fibers through a series of rollers with wire teeth that comb out the shorter fibers.
  4. Blending of fibers: Carding is often used to blend different types of fibers together, such as cotton and polyester, to produce yarns with specific properties. The carding process helps to ensure that the fibers are evenly distributed throughout the blend.
  5. Fiber orientation: Carding also helps to align the fibers in a consistent direction, which makes it easier to spin them into yarn. This orientation also improves the strength and durability of the resulting yarn.
  6. Formation of sliver: The carded fibers are collected in a thin web form called a sliver, which is then used for spinning into yarn. The carding process helps to create a uniform sliver that is free of impurities and has consistent fiber orientation.

Overall, the carding process plays a critical role in preparing the raw materials for spinning into yarn. It helps to remove impurities, extract neps, remove short fibers, blend fibers, align the fibers, and form a uniform sliver that is ready for further processing.

Carding is known as the heart of the textile spinning mill 

Carding is often considered the heart of the textile spinning mill, as it is a crucial process that transforms raw fibers into a form that can be further processed into yarn. During the carding process, fibers are separated, straightened, and blended to create a continuous strand of material known as a sliver. This sliver can then be processed further using machines such as draw frames, roving frames, and spinning frames to create yarns of different sizes and qualities.

Because the carding process plays such a central role in the production of high-quality yarns, it is essential that it is carried out with great care and attention to detail. This includes selecting the right equipment, maintaining it properly, and employing skilled operators who understand the nuances of the process. With the right approach, carding can help textile mills produce high-quality yarns that meet the needs of their customers and the broader market.

Where to use the Breaker carding machine

Breaker carding machines are commonly used in the textile spinning industry to process a wide range of fibers, including cotton, wool, jute, and synthetic fibers. They are particularly useful for processing fibers that are initially too long or too coarse for direct spinning, as the machine can effectively separate and straighten the fibers to produce a uniform sliver that can then be processed further.

Breaker carding machines are typically used in the early stages of textile spinning after the fibers have been cleaned and prepared for processing. They are often used in combination with other machines, such as finisher carding machines and draw frames, to further refine and prepare the fibers for spinning into yarns. Overall, the breaker carding machine plays an important role in the textile spinning process, helping to produce high-quality fibers that can be spun into a wide range of products.

Material passage diagram of carding machine

A brief explanation of each component of a carding machine:

1. Feeder Hopper: This is the initial stage of the carding process, where the raw material (such as cotton or wool) is fed into the machine through a hopper.

2. Licker-in Cylinder: This is the first rotating cylinder that separates the material into individual fibers and also removes any impurities that may be present.

3. Drum / Cylinder: This is the main rotating cylinder of the carding machine, which further separates and aligns the fibers using wire teeth or “clothing”. The drum is surrounded by stationary “flats” or bars, which brush against the drum and help to straighten the fibers.

4. Revolving Slates: These are adjustable metal plates that are positioned near the cylinder to control the feeding and alignment of the fibers.

5. Brushing Rollers: These are small rollers that help to clean and align the fibers before they are transferred to the next stage of the carding process.

6. Doffer: This is a rotating cylinder that removes the carded fibers from the main cylinder and forms them into a thin, continuous strand known as a sliver.

7. Drawing Unit: This section of the machine is responsible for further aligning and drafting the fibers to improve their consistency and quality.

8. Trumpet Guide: This is a funnel-shaped guide that helps to guide the fibers smoothly into the drawing unit.

9. Grid Roller: This is a roller with a series of grooves that helps to comb and align the fibers as they are drawn through the machine.

10. Sliver Cane: This is the final product of the carding process, which consists of a long, continuous strand of fibers that are wound onto a large spool or “cane”.

Action in Carding Machine: Mainly four types of action happen in carding machine, these are following:

1. Combing action: This action takes place between the feed roller and taker-in, where the tufted fibers are separated into individual fibers and opened up.

2. Carding action: This action takes place between the main cylinder and flats, where the individual fibers are further separated, straightened, and aligned in a parallel direction.

3. Stripping action: This action takes place between the cylinder and doffer, as well as between the taker-in and cylinder. The stripping action removes the fibers from the pins of the cylinder or taker-in by using a faster-moving roller or comb.

4. Doffing action: It is the process of removing the carded fibers from the main cylinder onto the doffer. The doffer is a cylinder with a fine wire clothing that rotates in the opposite direction of the main cylinder. As the main cylinder rotates, the carded fibers are deposited onto the doffer and form a thin layer on its surface. The doffer then rotates and removes the fibers from the main cylinder by means of the card clothing’s stripping action. The fibers are then collected in the form of a continuous web or a sliver.

Design and working of carding machine

• The blowroom lap is the feed material for the card.

• Material is fed via a pipe duct into the feed chute of the card.

• An evenly compressed batt of about 500-900ktex is formed in the chute.

• Transport rollers forward the material to a feed arrangement that comprises of feed rollers and feed plates.

• It pushes sheet of fibres slowly into the operating range of taker-in.

• Taker in has saw-tooth wire thoroughly combs and opens the sheet of fibres into flocks.

• Flocks pass over grid equipment and are transferred to the main cylinder.

• The impurities are recovered when material moves past the mote knives, grids, carding segments, etc.

• Suction ducts carry away the waste.

• The actual carding process takes place between the main cylinder and flats where flocks are opened into individual fibres.

• Flats consist of 80-116 individual carding bars which are combined into a band moving on an endless path.

• 30-46 bars of the flat are located in the carding position of the main cylinder.

• Flats help in removal of short fibres.

• Long fibres are continually carried along by the main cylinder as they offer more surface to the clothing of the main cylinder.

• A cleaning unit strips fibres, neps and foreign matter from the flat bars.

• Fixed clothing bars assist carding operation.

• Grids or cover plates enclose the bottom surface of the main cylinder.

• After carding the doffer carries the long fibres that lie loose and parallel without hooks onto the main cylinder.

• It combines fibres into a web form.

• A pair of rollers draw the web from the doffer.

• A pair of calendar rollers compresses the web into a sliver.

• The sliver passes through a trumpet into the nip of the coiler calendar rollers.

• The coiler calendar rollers compress the sliver and deposit it in the form of coils into a rotating cylindrical can.

Characteristics of Card Sliver:

  • Fibers in card sliver are oriented in different direction.
  • Hook and also projected fiber present in card sliver.
  • The uniformity of sliver is not very good.
  • In the web there are 50% fiber exhibit tailing hook, 15% leading hook, 15% both ends hook and a small portion without hook.

Cleaning efficiency of carding machine: 80-90%

Draft necessary at carding machine: 80-120

Production per carding machine: 30-70 Kg/hr

Although the carding process is essential in the textile industry, there are some disadvantages associated with it:

1. Fiber damage: The carding process can cause damage to the fibers, especially if the machinery is not maintained properly. The fibers can be broken or damaged during the process, which can affect the quality of the yarn.

2. Loss of fiber: The carding process results in a certain amount of fiber loss, which can reduce the yield of the spinning process. The amount of fiber loss can be significant if the machinery is not functioning properly.

3. Production of waste: The carding process generates waste in the form of short fibers, dust, and other impurities that are removed from the raw material. This waste can be difficult to dispose of and can also be a source of pollution.

4. Energy consumption: The carding process requires a significant amount of energy, which can be a significant expense for textile mills. The energy consumption can be reduced through the use of more efficient machinery, but this can be expensive to implement.

5. Maintenance: The carding machinery requires regular maintenance to ensure that it is functioning properly. This can be time-consuming and expensive, especially if the machinery is older or has not been maintained properly.

Recent development: 

  • Metal detector
  • Auto leveling
  • Continuous suction
  • Electronic control system and display necessary quality report.

References:

  • Klein, W. (1987). A Practical Guide to Opening and Carding. Textile Institute.
  • Klein, W. (n.d.). The Rieter Manual of Spinning. Rieter Machine Works Ltd.
  • W Klein, H. S. (2004). A Practical Guide to the Blowroom and Carding – Manual of Textile Technology (2 ed.). Textile Institute.

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