DEFINATION OF PIRN AND IT'S PREPRATION FOR LOOMS:-

DESCRIPTION OF PIRN:-

Here it is necessary to give the it’s description and preparation of a pirn because it is the main apparatus used for weft supply in any loom.

PIRN:-

Pirn is a rod on to which weft thread is wound for use in weaving . Unlike a bobbin it is fixed in the middle of the shuttle , and thread delivered off end of the pirn rather than from the center.

A typical pirn is made of wood or plastic (nylon) and is slightly tapered for most of its length, flaring out more sharply at the base which fits over a pirn in the shuttle. Pirns are wound from the base forward in order to ensure snag free delivery of the thread , unlike bobbins which are wound evenly from end to end.

Image of shuttle with pirn. ref by Shutterstock.com

Pirn became important with the development of the flying shuttle, they are also used with other end delivery shuttle. Power looms which use pirns generally have automatic changing mechanism which removes the spent pirn from the shuttle and replace it with fresh one , thus allowing for uninterrupted weaving.

image (1) wooden (2) nylon

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Pirn winding process:-

Winding of a pirn (quill) is different from the regular winding process . In quilling the weft yarn is transferred from larger package to smaller quill (pirn), which is shown in figure. Also inspection of yarn is not part of the process, therefore there is no yarn clearing zone.

The traverse mechanism is also different because of different geometry of the quill (pirn) . The traverse here does not go back and forth along the package. It only builds yarn in open part of a bobbin on ring spinning frame. This type of winding helps reduce ballooning effects , maintain uniform tension, and reduce the possibility of Slough off.

The machine that are used to wind pirn (quill) are called “Quillers” or “ Pirn winding" machine. These machines are automatic which means that when the quill is filled(wounded full) , it is doffed and an empty pirn is place on the spindle automatically with the elemination of the shuttle looms, the quill winding process is also disappearing.

Ref:-https://textileapex.blogspot.com

Working principle of a pirn winding machine:-

As explained above the pirn winding is the process of transferring weft yarn on the small pirn able to use in the shuttle of a loom.

Passage of yarn in a winding machine:-

The yarn package (cone or chese) is mounted on the cone holder. The yarn coming from the package passes through a thread guide. Now this yarn passes through a yarn tensioner . This tensioner imparts required tension to the yarn and helps to regulate the yarn winding density on pirn . The yarn again passes through another thread now. The yarn these passes through a yarn traverse guide makes to and fro movement during the winding process. Yarn finally gets upon the pirn after starting the machine.

schematic digram of pirn winding 

WORKING:-

In weft winding machine, the pirn is driven by an spindle. The weft wound on this process parallel package result. Also instead of winding them back and forth the weaver winds them a half inch at a time . The pirn is mounted on the spindle driven by a mechanism that consist of gear and cam. The pirn rotates at a very high speed . When the diameter of pirn increases upto a little extent due to less amount of yarn on the pirn. When it rotates it drags the yarn and winds on it. This package comprises one or more threads that are laid very nearly parallel to the layers already existing on the package.

The yarn receive to and fro motion through the traverse guide. The yarn guide performs the traversing motion of yarn. Yarn traverse guide which makes nearly parallel coils of yarn on the pirn . Almost half inch of pirn (chasing length) get at a  time. At a time the yarn moves to and fro between half inches distance of pirn. When this half inches is filled , the winding of next half inches begins , thus the winding of complete pirn is performed. The chasing length get shifted gradually during winding . The weft bobbin or pirn contains a very less amount of yarn length on it because it is very difficult to throw a shuttle with pirn contains a high amount of yarn on it . After the completion of length on the pirns it stop automatically and comes out from the machine and a new pirn is again placed and started winding a new . The process can be continued till the requirement of pirn (bobbin) for weaving.

Types of pirn widing machine:-

1. Ordinary pirn widing machine .

2. Automatic pirn winding machine.

(1) Ordinary pirn winding:-

In this machine the has been taken out from it manually after completion of a certain amount of length wound on it. After taking out it then a new empty pirn is placed on the spindle and winding is continued for next preparation of pirn. And the continued till sufficient quantity of pirn required for weaving.

(2) Automatic pirn winding machine:-

As shown in the above figure this two machines are automatic pirn winding machine. In this machine the pirns comes out after completion of length and a new pirn is placed at its place on the widing spindle and the winding started for fresh pirn, and this process is continued upto requirements of pirn for weaving fabrics.

Features of pirn winding machines:-

1. In pirn winding machine the resulting (out put) package is many time smaller than the supply package.

2. It is almost not capable to eliminate objectionable yarn faults during winging.

3. Re-joining of yarn does not take place.

4. Traverse has the characteristic of an oscillation in which the package diameter is controlled continuously.

5. It necessitate building a bunch on pirn for reserve yarn.

6. At the time of beginning the winding tension is less. As the diameter increases winding tension also rises.

Advantages of winding machine:-

a) Maximum number of pirn can be produced at a time.

b) Surplus of the pirn can be produced to avoid the shortage of weft during weaving.

c) An even length and weight is wound.

d) An ordinary weaver can operate this machine.

e) Production can be more due to bulk ready pirns.

Disadvantage of winding machine:-

A) A small length of weft is obtained

B) Any defective pirn produce has to be rewind.

C) Reserve yarn causes the weft wastage.

D) Defective yarn can’t be removed during the winding.

E) Different yarn tension on the pirn can give faulty fabric.

Ref:-https://www.textileadvisor.com