Fabric and Garment Finishing
Shrinkage is the contraction in the dimension of the fabric due to usage.
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.
Various mechanical and chemical finishes have been adopted on cotton fabric to overcome shrinkage during subsequent washing. All the chemical and mechanical finishes have got some disadvantages like DMDHEU releasing formaldehyde which affects skin. Hence a chemical such as Resil CLS (modified glyoxal) can be given on 100 % cotton knitted fabric to overcome the problem of shrinkage during subsequent washing and also it does not releases formaldehyde.
Chemical Modification of Cellulose
Chemical modification of cellulose has been widely practiced to improve its mechanical properties of dimensional stability, wrinkle resistance and crease recovery which play an important role in the appearance, handle and easy care properties of fabrics.
Chemical modification of cellulose presently involves cross linking it with resin. This method evolved from the formaldehyde based condensation with urea or urea derivatives and poly-carboxylic acids.
The urea derivatives include di-methylolurea, di-methylol ethylene urea, dimethylol alkyl carbamate, tri-methylol melamine, di-methylol di-hydroxy ethylene urea.
The poly-carboxylic acids include butane tetra-carboxylic acid, citric acid, cyclopentane tetra-carboxylic acid, tetra hydro furan-tetra-carboxylic acid, nitrilo tri-acetic acid and ethylene diamine tetra-acetic acid etc.
Mechanism of Chemical Modification of Cellulose
Cotton fibers normally swell 42 % to 45 % during laundering in the presence of moisture and change their
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.
Various mechanical and chemical finishes have been adopted on cotton fabric to overcome shrinkage during subsequent washing. All the chemical and mechanical finishes have got some disadvantages like DMDHEU releasing formaldehyde which affects skin. Hence a chemical such as Resil CLS (modified glyoxal) can be given on 100 % cotton knitted fabric to overcome the problem of shrinkage during subsequent washing and also it does not releases formaldehyde.
Chemical Modification of Cellulose
Chemical modification of cellulose has been widely practiced to improve its mechanical properties of dimensional stability, wrinkle resistance and crease recovery which play an important role in the appearance, handle and easy care properties of fabrics.
Chemical modification of cellulose presently involves cross linking it with resin. This method evolved from the formaldehyde based condensation with urea or urea derivatives and poly-carboxylic acids.
The urea derivatives include di-methylolurea, di-methylol ethylene urea, dimethylol alkyl carbamate, tri-methylol melamine, di-methylol di-hydroxy ethylene urea.
The poly-carboxylic acids include butane tetra-carboxylic acid, citric acid, cyclopentane tetra-carboxylic acid, tetra hydro furan-tetra-carboxylic acid, nitrilo tri-acetic acid and ethylene diamine tetra-acetic acid etc.
Mechanism of Chemical Modification of Cellulose
Cotton fibers normally swell 42 % to 45 % during laundering in the presence of moisture and change their