The essential Knowledge about winding(1)

The Essential Knowledge about Winding

Winding

The process of transferring yarn from ring bobbins, hanks, cones etc onto a suitable package is called Winding.

Objectives of Winding

To transfer the yarn from spinner’s package onto a convenient form of package which will facilitate weaving or the net process of yarn preparation.
To have desired length of yarn on the package.
To remove yarn fault and improve quality.
To make quality fabric.
To store the yarn properly.

Winding Requirements

The fault level in the yarn must be reduced to an acceptable level.
The yarn must not be damaged in any way in the winding process.
The yarn must be wound in such a way as to permit unwinding in the following processes with a minimum of difficulty at the required speeds.
The package size, shape, and build must be the most technologically suitable for the particular end use.
The package size should be controlled to meet the particular economic requirements.
The winding operation must be geared to give the best possible economic performance of the whole process of fabric manufacturing.

Different Types of Package with their uses

1. Cheese packages
2. Cone packages
3. Pirn packages
4. Flanged bobbin
5. Spool packages
6. Cop packages

Types of Packages

Based on the winding process, yarn packages can be grouped under three categories:

The parallel wound package
The Near-parallel wound package
Cross-wound packages

1. Parallel wound package:
This package comprises many yarns laid parallel to one another as in a warp beam. It is necessary to have a flanged package. For instance, Warper’s Beam, Weaver’s Beam.

Advantages:
a) Many yarns can be wound at a time.
b) More yarn density in the winding package.
c) Side withdrawal is possible.
d) During unwinding no change of twist.
e) During winding no need to traversing.

Disadvantages:
a) Need flanged packages.
b) Need separate mechanism during unwinding.
c) Over withdrawal is not possible.

2. Near Parallel wound package:
This package comprises one or more yarns which are laid very nearly parallel to the layers already existing on the package. For instance, Pirn, Cop.

Advantages:
a) Normally no need of flanged package.
b) Over withdrawal is possible.
c) The package is comparatively stable.

Disadvantages:
a) During unwinding twist may be changed.
b) Side withdrawal is not possible.
c) During winding need traversing mechanism.

3. Cross wound package:
This type usually consists of a single yarn which is laid on the package at an appreciable helix angle. So that the layers cross one another and give stability. For example, Cone, Cheese etc.

Advantages:
a) Package stable due to cross wound.
b) Over withdrawal is possible.
c) During unwinding no need of separate mechanism.

Disadvantages:
a) The amount of yarn in the package is less due to low density.
b) Twist will be changed during unwinding.

Yarn Withdrawal

There are two ways in which a yarn package may be unwound-
1. Side withdrawal
2. Over end withdrawal/over withdrawal.

1. Side Withdrawal:

Package must rotate positively or negatively.
Expensive if package is rotated positively.
Yarn twist unchanged.
Low unwinding speed.

2. Over end withdrawal:

Package is stationary
Yarn twist changes during unwinding.
High unwinding speed.

Difference between Side withdrawal & Over end withdrawal

Side withdrawal	Over end withdrawal
1. Package must rotate.	1. Package is stationary.
2. No balloon formation.	2. Balloon formation.
3. No change of yarn twist.	3. Change of yarn twist.
4. Unwinding is not fast.	4. Unwinding is fast.
5. Parallel package.	5. Cross-wound package.
6. This process is expensive.	6. This process is cheap.
7. Flanged bobbin needs.	7. No flanged.