The verb ‘singe’ literally means ‘to burn superficially’. Technically, singeing refers to the burning-off of. Loose fibres not firmly bound into the yarn and/or fabric structure. Singeing is an important part of pretreatment. This is the burning off of protruding fiber ends from the surface of the fabric. If not done properly, unclear print patterns, mottled fabric surfaces, and pilling results.
- Loose yarns not firmly bound into the fabric structure;
- Protruding fibre ends sticking out of the textile yarns and/or fabrics.
- Singeing of a fabric is done in order to obtain a clean fabric surface which allows the structure of the fabric to be clearly seen.
- Fabrics, which have been singed, soil less easily than un-singed fabrics.
- The risk of pilling, especially with synthetics and their blends, is reduced in case of singed fabrics.
- Singed fabrics allow printing of fine intricate patterns with high clarity and detail.
- The risk of skittery dyeings with singed articles dyed in dark shades is considerably reduced, as randomly protruding fibres are removed in singeing which could cause diffused reflection of light.
Singeing of textile materials is necessary for te following reasons:
- Cotton materials are valued for their smooth appearance. After the formation of fabric it has a fuzzy or hairy appearance due to projecting fibers, thus affecting the luster and smoothness cotton is known for.
- Unsigned fabrics are soiled easily
- The protruding fibers obstruct the subsequent dyeing and printing process
- Goods which are to be mercerized are signed to maximize the luster
- In fabrics of polyester and cellulosic fiber blends singeing is the best method to control pilling, sometimes double singeing is done to minimize the pilling.
Singeing process is as follows:
- To produce a smooth surface finish on fabrics made from staple fibers first the fabric surfaces are brushed lightly to raise the unwanted fiber ends.
- Then the fabric is singed with or passed over heated copper plates or open gas flames. The fiber ends burn off.
- The fabric is moved very rapidly, and only the fiber ends are destroyed.
- As soon as the fabric leaves the singeing area, it enters a water bath or desizing bath. This stops any singeing afterglow or sparks that might damage the cloth.
Precaution During Singeing
Some of the precautions to be taken in considerations during singeing:-
- The fabric to be singed should be dry as wet fabric tend to scorch more readily than dry.
- Uneven singeing may cause streaks on fabric or bubbles when the fabric is finished.
- Improper singeing may lead to loss of 75 % loss in tensile strength loss in warp direction.
- The fabric should not contain any acid releasing salt,which may release acid on heating and tender the fabric.
- Stopping the machines may cause bars on the fabrics.
- Singeing may cause hardening of the size thus leading to difficulty in its removal.
- Possibility of thermal damage to temperature sensitive fabrics.
- The burning characteristics of fibers must be taken into account when this process is applied, as heat-sensitive fibers melt, forming tiny balls on the surface of the fabric. These balls interfere with dye absorption, so that, as a general rule, heat sensitive fibers would be singed after dyeing or printing.