yarns are needs to be transferred from spinning packages of cone or cheese to the packages of pirn that will facilitates the weaving. It can be done by manual or by pirn winding machine.
A tapered bobbin having weft yarn on it is called as pirn and this is the final feed to the shuttle. There are different types of pirns like nylon pirns, wooden pirns used. Weft yarn is also called as filling yarn.
Objectives/necessity of weft preparation:
To mount the packages in the shuttle easily.
To prepare the weft as desired on the loom.
To rewind the yarn on to pirn.
To remove the yarn faults such as slubs, thick and thin places, hairy fibers etc.
To remove unwanted dust during preparation.
To check quality of wound package.
To prepare the pirns for different types of looms.
To improve the uniformity of fabric.
Methods of weft preparation:
Use of ring cop in shuttle which is not desired as the ring cop is with defects. Further the ring cop cannot be accommodated in shuttle.
Rewinding of weft:
This is the most popular method as the yarn s rewound from wound packages like cone, cheese, spool etc. This method also serves as a method of check of quality of wound packages.
Here no shuttle and pirn are used. Cones or cheeses or spools are directly used in loom as a source of weft supply.
Advantage of this method is that pirn winding is completely eliminated.
Unifil loom winder:
In this system the pirn is wound on the loom itself. In other words, every loom is attached with a winder. But this method is very costly and absolete.