Weft Preparation

On conventional loom the filling yarn is inserted by means of a shuttle carrying a bobbin. This bobbin should be tapered at the end so that the yarn may be pulled without interruption through the eye of the shuttle as the shuttle travels from one side of the loom to the other.

Objects of weft preparation

To remove the slubs on the weft yarn.

To handle the small lots easily

To use the better pirn on the loom.

To improve the uniformity of the fabric

Necessity of Weft Yarn Preparation

1.   Removal of slubs & weak places during processing which otherwise would impair the running of the loom.

2.   The production of the tighter packages having more yards per pirn. This reduces the number of pirn changes in the loom. This, in turn, reduces the possibilities of flaws & wastage.

3.   Greater uniformity of pirns used on the loom. This improves the uniformity of the fabric.

4.   The easy handling of small lots.

Advantages of filling preparation:

1.   Removal of slubs and weak places during processing which otherwise would impair the running of the loom.

2.   The production of tighter packages having more yards per pirn. This reduces the number of Pirn changes in the loom which, in turn, reduces the possibilities of flaws and wastage.

3.   Greater uniformity of pirns used on the loom. This improves the uniformity of the fabric.

4.   The easy handling of small lots.

Conditioning of filing

This process is the same whether pirn are made on spinning or twisting frames, or wound on a pirn. It involves the wetting or steaming of the filling yarn to stabilize it so that it will weave satisfactorily. An unconditioned yarn is usually “Lively”; if allowed to go slack, it will snarl as shown in Figure.