Yarn Dyeing

Yarn Dyeing:

In general wet processing of textiles, whether it is fiber, yarn or fabric dwells with the same chemistry. Only the application machinery is different.

Garment dyeing is one more divide in textile processing, where stitched garment pieces are dyed in the final stage.

The manufcturer of garment selects the method of processing according his special end use requirements. For example, if he wishes to produce a muti-colored stripped or checked shirting, he would opt for yarn dyeing and on the other hand if he wants to produce a solid shade for some trousering material, he prefers fabric processing after weaving are knitting.

According to his requirement,the manufacturer selects the phase of processing. In this blog we wish to focus on the various aspects of yarn dyeing.

We are well aware that yarn is available in the form of reeled hanks and wound cone/cheeses.

At this point the yarn dyeing industry itself divides in to two sectors. One as Hank yarn dyers and the other cheese dyeing units.

Hank Yarn Processing:

Any wet processing comprise of 3 parts. (1) Pretreatment, (2) Dyeing and (3) Finishing. Processing of yarn also comprise of the same above 3 parts. Let us have a look in to this.

Pretreatment of Yarn:

Pretreatment, as the name suggests is the first part in processing. According to the end use of yarn, the pretreatment starts. If the apparel manufacturer requires, a flaw less, smooth lusturouros yarn for his baby garments, then the process sequence is the one below.

1. Gas singeing
2. Grey Mercerising
3. Scouring and bleaching

Cheese Dyeing:

Special machineries are used to process yarn in cheese form. Cheese dyeing machineries are more sophisticated and automated when compared to the hanr dyeing machineries.

As said above, pretreatment of yarn in cheese form comprises of the following stages.

1) Gas Singeing and (2) grey mercerising has to carried out either from hank form or cone form. If the yarn is available in cone form, it is wound from one cone to another and in between the pasage length the gas singeing would be carried out.

2) Mercerisation is possible only if the yarn is in hank form.

3) Preparation of yarn in cheese form (Cheese Winding)ie., from hank or cone form it has to be convented in to cheese form using special winding machines. This is a very important stage in cheese processing. The package density of yarn over the cheese should be uniform throughout the length.

4) Scouring and bleaching.

Let us have detailed description of all stages one by one in my next posting. You can have a good reference of all textile processing in the "Textile Processing Guide - thesmarttime.com"