PROCESSING SEQUENCE TWISTED YARNS

FILAMENTS FOR WEAVING AND/OR KNITTING 

These filaments should have 100-200 t.p.m. This can be done by means of the following sequence:

1. Extrusion of the melt.

2. Drawing of the yam in a draw twister. The drawn yarn will have

3. Twisting the drawn yam in a ring-less or deck twister.  

SEWING THREADS

Sewing threads exhibit high breaking strength, good elasticity, uniformity, softness, flexibility with a minimum number of knots. The threads are usually manufactured by doubling three priorly twisted threads and twisting them in the direction opposite to the twist of singles. The amount of single twist and/or ply twist varies in the range of 400-700 t.p.m. This is a multistage process and involves the following operations, after the filament formation.

1.  Stretching of the yarn after spinning.
2.  The winding of the yarn on the requisite material for twisting. 
3.  Twisting in a twister. 
4.  Doubling of three ends with simultaneous twisting.
5.  Further processing operations like heat-setting, drying dyeing, etc.

Alternately the operations can be as follows:

1. Stretching of the yarn.

2. Winding on the particular form.

3. Twisting in a ring-twister.

4. Doubling of two or three threads.

5. Ply twisting in a ring-twister.

6. Further processing operations like winding, heat- the setting, drying, dyeing, etc.

YARNS FOR TYRE CORD

The yarn used for type cord should fulfill the following characteristics: high breaking strength, high elasticity, good heat resistance, low hygroscopicity, high fiber and yam density, high resistance to all type of deformation like compression, bending, rubbing, etc and above all uniformity
in all the above properties. The cord is produced from the twisted and plied filaments as per the following processing sequences after the formation of the filaments.

1. Two-stage Stretching of the filaments after spinning.

2. First twisting in a special type of ring twister, which will accommodate heavy packages. The twist will be 300-500t.p.m depending upon the yarn thickness.

3. Second twisting i.e., cording or twisting of 2-4 twisted yarn, produced from first twisting. The twist will be the same but in the opposite direction of the first twist.

4. Further processing like cord fabric formation and cord formation.