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 preshrinking.
Cotton is mainly selected for apparel purposes because of their durability, ability to withstand the rough laundering treatment especially under alkaline conditions, good perspiration absorption characteristics, and comfort during wear and ability to take up a wide range of dye stuffs. But the main problem with the cotton fabric is shrinkage during washing or laundering. Shrinkage is undesirable property to the apparels. So the material has to be either shrink resistant or shrink recoverable.
The main objective of anti-shrink finish is to keep the fabric smooth and free from undesirable shrinkage. So this finish is referred to as Anti-shrink or Shrink-resistant or shrink recovery finish. This finish is purely chemical and permanent finish. Usually cotton, linen, viscose and cuprammonium rayon are finished with resin. The finishing process by which the cotton knitted fabrics are made not to shrink is known as "Anti-Shrink Treatment".
Different types of knitted fabrics such as single jersey, interlock and flat back rib were treated with Resil CLS using pad-dry-cure technique. Also dosage of the chemical and pH were also changed to study their effect on the treated fabric. The chemically treated knitted fabric is also tested for dimensional stability, spirality, bursting strength and formaldehyde content as per the standard test methods. Dimensional stability and spirality has found to be improved compared to that of untreated fabric. Resil CLS treated fabric resulted in a strength loss of 15 %, it is comparatively less than that of other cross-linking agents. It was found that only 4.05 ppm of formaldehyde was released from the fabric which is acceptable and negligible as per the standards.
The authors are associated with the Dept. of Textile Technology PSG College of Technology, Coimbatore.
Originally published in Textile Review, December 2011
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