In spinning sector of textile manufacture, carding process is known as the heart of spinning. Carding is defined as the reduction of entangles mass of fibres into a filmy web which is done by working between two closely spaced and relatively moving surface clothed with the sharp wire points. It is a mechanical process that disentangles, cleans and intermixes fibres to produce continuous web or sliver suitable for subsequent processes.
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| Carding process |
The cotton comes-off of the picking machine in laps, and is then taken to carding machines. The carders line up the fibres nicely to make them easier to spin. The carding machine consists mainly of one big roller with smaller ones surrounding it. All of the rollers are covered with small teeth, and as the cotton progresses further-on the teeth get finer (i.e. closer together). The cotton leaves the carding machine in the form of a sliver; a large rope of fibres.
The objective of carding in spinning is opening the flock into individual fibres, extracting of neps, removal of very short fibres, blending of fibres, creating partial longitudinal orientation of fibres, formation of the sliver. Carded yarn is a cotton yarn which has been carded but not combed. This type of yarn contains a wide range of fibre length.
Combing is the process of preparing carded sliver for spinning. Combing separates out short fibres by means of a rotating ring or rectilinear row of steel pins. The fibres in the 'top' it produces, have been straightened and lie parallel to each other.
The wastage which is removed from the comber machine during processing is known as combers' Noel or Noil. It is expressed as percentage. It is mainly of short fibres and neps. Noel is used for lower count as raw material. Depending on what is being produced, waste from combing varies from 12 - 25%, and this can be employed to obtain yarns with a medium coarse count using the open-end spinning process.
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| Combing Process |
Combing the fibres removes the short fibres and arranges the fibres in a flat bundle, with all the fibres going the same direction. This preparation is commonly used to spin a worsted yarn. Woollen yarn cannot be spun from fibres prepared with combs, instead the fibres must be carded. Cotton is combed when it is to be used for quality fabric with high thread counts. In general, combing is done either to filter or sieve out any short length fibres; for example fibres shorter than 21 mm.
Few key differences between carded & combed yarns are:
- Carding creates a slightly fuzzier yarn as not as many of the fibres are aligned. Combing on the other hand creates a smother yarn as the fibres are more aligned.
- Combing is the more expensive process as you have higher waste involved than with carding.
- Combed yarn and carded yarn have great effect on gram per square meter (GSM). Carded yarn produces lower GSM fabric than combed yarn, while using the same count for both types of yarn.
- Normally, combed yarns are more uniform than carded yarns.
- Combed yarn twist per inch (TPI) is lower than carded yarn.
- While the yarn count is same then shrinkage of all types of fabric produced from carded yar is more than that produced from combed yarn.
- Normally, carded yarn strength is lower than combed yarn of the same count.
- Carded yarn is more hairy than combed yarn.
- Combed yarn is more lustrous than carded yarns.
- Fabric made of combed yarn is gentle against the skin.
- Combed yarn production process is not easier than carded yarn production process.
- Carded yarn is cheaper than combed yarn.
- The resistance of pilling effect on fabric surface produced by combed yarn provides better result than same count of carded yarn.
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