Shrinkage is the contraction in the dimension of the fabric due to usage. Cotton fabric suffers from two main disadvantages of shrinking and creasing during subsequent washing. Creasing is overcome by the resin finishing whereas the shrinking is prevented by a special finishing known as sanforising and the machine used for that purpose is known as Zero-Zero pre shrinking


The shrinkage of cotton goods on laundering has long been one of the major problems requiring the attention of the textile technologists. At one time or another all of us have been subjected to the annoyance of the shrinkage of our personal clothing during laundering collars, shirts for men, underwear, frocks for women for example.


In the laundering of cotton goods, the full shrinkage is not always produced in the first wash and often three launderings are required before dimensional stability is reached. It has generally been found that a fabric which shrinks 5% in first washing treatment may shrink 7% before reaching stability. The ratio of the final shrinkage to initial shrinkage is often 1:4.


Shrinkage is the contraction in the dimension of the fabric due to usage. Cotton fabric suffers from two main disadvantages of shrinking and creasing during subsequent washing. Creasing is overcome by the resin finishing whereas the shrinking is prevented by a special finishing known as sanforising and the machine used for that purpose is known as Zero-Zero pre shrinking machine.


Cotton has the property of swelling in water and this effects shrinking. Also the mechanical stress, strain and tension, during spinning and weaving etc, when released cause the fabric to shrink.


The cotton fabric, when put in water, swelling takes place and rearrangement of internal forces takes place. The fibres will become free from tension and it comes to the original tensionless state.


These are the reasons for shrinkage:

  • In case of a fabric, the warp yarns are under much strain due to interlacement than the weft yarns. Hence when a fabric is allowed to shrink, the warp yarn shrinkage will be more than weft yarns.
  • To overcome this fabric is extended in widthwise to some extent in the stenter machine during the finishing process. Then it is subjected to the preshrink process.

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The authors are associated with the Dept. of Textile Technology PSG College of Technology Coimbatore


Originally published in Textile Review, November 2011

 

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