Winding

Winding

Winding is a process of transferring

yarn from one package to another or
from a number of small packages
(spinner’s packages, hanks) to a big
package i.e. a cone or cheese that is
more suitable for the next processes
such as warping or knitting or for any
other suitable use such as on shuttle-
less looms.
Winding objectives

• To transfer the yarn from the spinner's package onto a convenient form of packages which will
facilitate weaving or the next process of yarn preparation.
• To remove the objectionable faults present in original yarns.
• To have the desired length of yarn on the package.

Requirements of winding
▪ No damage of yarn
▪ Easy unwinding
▪ Suitable package size and shape
▪ Minimum fault
▪ Economical suitability
▪ package size, shape and build must be controlled
 Withdrawal of yarn
The unwinding process of yarn from package is called yarn withdrawal. There are two
ways in which a yarn package may be unwound:
1. Side withdrawal
2. Over end withdrawal/over withdrawal
Side Withdrawal: In side withdrawal, the package
(Beam/flange bobbin) must rotate in order for the
yarn to be removed.

Over-end withdrawal: The yarn is to take away

along a line which roughly coincides with the axis
of the package. Using this technique it is not Side withdrawal over-end withdrawal
necessary to rotate the package.
 Introduction with some important terms
Wind
It is the number of revolutions made by the package (i.e. number of coils wound on the package).

Angle of wind ( θ ) : It is the angle made by the yarn with the

sides of the package (Figure 2.3). If surface and traverse speeds
are Vs and Vt respectively, then
Tan θ=Vt ∕ Vs

Coil angle ( α ) : It is the angle made by the yarn with the axis
of the package (Figure 2.3). The coil angle and angle of wind
are complementary angles as they add up to 90°.
The net winding speed can be obtained by the resultant vector of surface speed (Vs) and traverse speed (Vt ).

Traverse ratio or wind ratio or wind per double traverse:

It is the number of revolutions made by the package (i.e. number of coils wound on the package) during the time
taken by the yarn guide to make a to and fro traverse. This to and fro traverses of the yarn guide from left to right
and back from right to left is known as double traverse.
Traverse ratio= 2× Wind
 Types of wound packages
There could be three types of wound packages based on the angle at
which the yarns are laid on the package.
❑ Parallel wound package
Warp beam/Weavers beam
In parallel wound package, yarns are laid parallel to each other. This helps to
maximize the yarn content in the package. However, parallel wound packages suffer
from the problem of stability and layers of coils can collapse specially from the two
sides of the package. Therefore, double flanged packages are sometimes used for
parallel wound packages.
Example: Weaver’s beam, warper’s beam Flange BobbinSpinners Bobbin Cop (Jute)
❑ Nearly parallel wound package
In nearly parallel wound package, successive coils of yarn are laid with a very
nominal angle. The rate of traverse is very slow in this case.
Example: Cop, Pirn, Spinners bobbin, Flanged bobbin Pirn
❑ Cross wound package
In cross wound package, yarns are laid on the package at considerable angle. As the
coils crosses each other very frequently, the package content is lower than that of
parallel wound package. However, cross wound package provides very good package
stability as the coils often change their direction at the edges of the package.
Example: Cone, Cheese, Spool Spool (Jute) Cone Cheese
 Advantages & disadvantages of wound packages
Wound Packages Advantages Disadvantages

Parallel • many yarns can be wound at • flanges are required

the same time • separate mechanism is required
• no need of traversing guide to unwind the yarn
• no change in yarn twist • over withdrawal is not possible
occurs
• the package is stable
• side withdrawal is possible

Near Parallel • flanges are not required usually • side withdrawal is not possible
• over withdrawal is possible • traversing motion is required
• partial change in yarn twist
occurs

Cross-wound • flange is not required • the yarn twist is changed during

• yarn package is very stable this winding
• over withdrawal is possible • traversing mechanism is required
 Winding Types
Precision winding
By precision winding successive coils of yarn are laid close together in a parallel or near parallel manner.
By this process it is possible to produce very dense package with maximum amount of yarn stored in a
Given volume. Θ≈90°
Non-precision winding
By this type of winding the package is formed by a single yarn or thread or bundle of yarn which is laid on the
package at appreciable helix angle so that the layers cross one another and give stability to the package.
The formed package is less dense but more stable. Θ<80˚

Precision Winding Non-Precision Winding

The wound coil arranged parallel or near parallel. The coil is cross wise wound.
The yam density of the package is high. The yam density of the package is low.
Flanged bobbin may be used. Not use of flanged.
The yarn package is hard and more compact. The yam package is soft and less compact.
Low stability of the package. High stability of the package.
Winding angle 0-10degree. Winding angle more than 10 degree .
The bobbin is wound with one or more yarns. The bobbin is wound with one or bundle of yarns.
Yarn tension is comparatively high. Yarn tension is comparatively less.
Unwinding rate is low. Unwinding rate is high.
 Methods of Driving the packages
There are two types of winding principle,
1. Surface contact drive or Drum driven winder
2. Direct drive or Spindle driven winder
a) Driving the package at a constant angular speed
b) Driving the package at a variable angular speed

1. Surface contact drive or Drum driven winder

2. Direct drive or Spindle driven winder (Constant or Variable RPM spindle winder)
 Traversing Methods

Reciprocating Rotating
• Common guide rod and traversing • Grooved roller with single groove
cam • Multiple grooves
• Individual rod and cam for each
spindle
Yarn passage diagram of winding machine
 Yarn Tensioner

According to working principle

• Capstan Tensioner
• Additive tensioner
• Combined tensioner

According to the type of working member

• Washer type
• Disc type
• Comb Type
• Roller type
• Ball type
• Two zone tensioner
Yarn guide
 Yarn clearing

The objective of yarn clearing is to remove objectionable faults from the supply package.

Two principles are used in modern winders for the identification of yarn faults.

• Capacitance principle

• Optical principle
 Yarn Ballooning

The rotation applied to the departing yarn during at high speed

of the yarn unwinding from a stationary yarn Yarn withdrawal
package, the yarn is thrown by centrifugal (over-end)
force away from the cop axis & circumscribes
in space a plane is called balloon

Factors that influence the size of balloon are

-Count
-Winding and unwinding speed
-Position of the guide
-Size and shape of the packages
 Faults and defects of Winding
1.formation of patches on the yarn
2.incorrect winding speed
3.package is too loose or tight due to tension variations
4.dirty package
5.incorrect shape of package
6.too many knots in yarn
7.excess yarn in bobbin
8.overlapping
9.two end winding
10.mixing of yarn of different linear density
11.unintentional pattern formation during winding
12.dirty yarn
13.poor yarn clearing and snarling
 Pirn Winding
The winding principle of pirn is different than that of cones and cheeses. If a cross-wound package is made then
there will be lot of tension variation during weaving. On the other hand, the parallel would package will give the
problem of instability. The base of the empty pirn is generally conical. The pirn winding starts from the conical
base and progressively proceeds towards the tip of the pirn. The distance travelled in one stroke of traverse is
known as chase length. One layer of coils are laid on the conical base during the forward and as well as during the
return movement of the traverse mechanism. Thus the conicity of the package is maintained and thus the tip of
the cone formed by the coils of yarn slowly proceeds towards the tip of the pirn.

Building of a pirn
 Mathematical Problem

1. The empty diameter of a spindle-driven cylindrical package is 5 cm. The spindle speed is 2000 r.p.m.
and traverse velocity is 100 m/min. Determine
a) Winding speed and angle of wind at the start

b) Winding speed and angle of wind when package diameter becomes double

2. The winding drum of a cone winding machine have a diameter of 3” makes 2870 revolutions. The actual
Amount of yarn wound in 9 hrs was found to be 332838 yds. Find out its efficiency?