3. Post-spinning operations

Of all the spinning processes described above, only continuous spinning yarns require additional mechanical operations, such as purification and media change, performed with a winder. Since the yarn is twisted by the rotation of the spinneret cop, its dimensions and geometry are optimized for production speed. The amount of yarn present on a cop is therefore reduced (between 50 and 200 g) compared with what is expected on a bobbin (between 1 and 2 kg). Wire from several cops is collected on a spool. The unwinding of the cops during winding is used to eliminate defects (coarseness and fineness) in the wire. In other processes, automatic or semi-automatic devices are developed to purify the yarn during spinning.

There are other mechanical and/or physical-chemical operations performed on cotton yarns.

• Steaming involves...