Singeing and Desizing
The process of singeing is nothing but removing the protruding fibers and making the fabric surface smooth . Desizing is the process of removing the size applied during
weaving.
Cotton Pretreatment
Pretreatment of cotton
in any form whether it is a yarn or woven fabric or knitted hosiery is the basic
requirement for any further
textile processing, whether it is for
whites or
textile dyeing or
textile printing. This pretreatment makes the fabric uniformly absorbent and white and is the basic requirement for successful
dyeing and finishing.
Pretreatment of wool
After shearing, wool is mechanically treated to shake out dirt and open the fleece in order to improve the efficiency of subsequent scouring. The raw
wool is then scoured by aqueous washing solvent scouring is less widely
practiced.
Pretreatment of Silk
To prepare a silk yarn for dyeing and silk fabrics for dyeing and printing, it is necessary to partially or completely remove sericin, as well as natural oils and organic impurities.
Polyamide Pretreatment
Polyamide fibers are classified into two types. viz., Nylon 6 and Nylon 66. Both the fibers vary in subtle physical and chemical properties. A general pretreatment of a polyamide fiber fabric is Scouring, Heat setting and Bleaching.
Mercerisation:
Mercerisation
is one of the most important processes of finishing cotton materials. It imparts gloss to the
fiber, increases its hygroscopic nature and strength and improves its
dyeability.
Viscose/Rayon Pretreatment:
Viscose
Scouring and bleaching need to be mild in nature. The fabrics should be scoured and should never be put directly into dye solution, as it is important to remove any residual Sulphur, to prevent dye reduction.
Spinning lubricants used on viscose tend to yellow with heat and so should be removed for best whites and bright pastel
shades. A detailed method of viscose
pretreatment, its properties, dyeing method etc., are explained in this article.
Spandex (lycra) Blends Pretreatment
A heat setting process that suits Lycra blends is suggested.
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