Creels in Warping
Creel: Creel is a platform which holds the supply packages like cone, cheese or spool in warping process.
Warping machine consists of several parts such as creel, open reed, head stock, warping drum etc. Feeding bobbins, cones, cheese or spools are fitted on metallic frames called as creels. These metallic frames consist of yarn tensioning devices which gives the uniform tension. But in latest machines instead of yarn tensioning devices they are provided with provided with centralized tension variation having automated control technique.
Creel capacity determines the number of warping sections. Generally, the warping creel capacity is 100-2000 bobbins. It ensures to hold the supply packages in proper positions. Creeling includes sampling of yarn, passing through tensioner, thread guide, drop wire and on to the beam.
Only single type of creel cannot give the same beaming efficiency for different types of yarns. There are many numbers of creels which are used for different purposes.
Types of creels:
Continuous chain creel
Swivel frame creel
Single end creel
a) Truck creel
b) Duplicated creel
This type of creel is in the shape of V and it diverges on both sides from its apex. And this apex is in line with the center of the machine.
It is the most popular creel which is used for superspeed operations.
Each column has package of capacity 540 ends.
All the bottom threads from each column are taken and deposited at the bottom of the column.
Merit of this creel is that open space available for creeling during working of the creel. So that the ends cannot touch or entangle with each other and provides easy withdrawal of yarn from supply package.
Tensioners are not available in this creel but the tensioning is by means of air drag.
This type of creel is in the shape of rectangle.
It is the most popular creel and with capacity available is 100-600 and 1000 packages.
It is used in slow speed warping machine.
The disadvantage of this creel is that creeling takes 45 minutes.
Efficiency of this creel is 50%.
In this type of creel, the tail end of the yarn is tied up with the tip of the yarn of another neighboring cone. So that the yarn in the first cone is exhausted or completed, the transfer second cone takes place automatically.
In this type of creel only half of the creel capacity can be used because for every active there is a reserve package. Means if the creel has 1000 package holders, then there are only have 500 ends in the warp sheet.
The advantage of this creel is that the creel is continuous in working as the yarn is shifted from active to reserve package.
When the same kinds of yarns to be processed, one has to go with magazine creel.
Continuous chain creel:
This type of creel is in the form of 2 arms and that forms an acute angle.
The yarn from the supply package holders carry an endless chain and it also moves the exhausted package away from the working position.
It is used for modern warping machines as it is a highly sophisticated creel.
This creel is a basically a truck creel but provided with automatic splice arrangement.
As the thread is pushed forward, threading takes place automatically.
It is designed to reduce the creel change time.
This type of creel used for warping of elastic yarns.
Used for propylene yarns in which packages are provided with brakers in the event of yarn breakage. The packages rotate to facilitate unrolling.
Yarn tensioning can be obtained by using positive thread feed.
Swivel frame creel:
It acts as a variation to mobile creel.
The bobbins which are weighing 5 to 25 kg cannot be pinned on trolleys.
So that the double-sided bobbin holder is used. In this type of bobbin holder, the threads are unwound from one side and an afresh series of bobbins are creeled up on the other side.
In this type of creel, bobbins are fitted or creeled on a particular trolley.
When the thread is exhausted on one trolley, the individual trolleys of bobbins placed one after the other in order to feed the warping machine.
The advantage of this creel is to reduce the waiting time for supply package.
Rotating frame creel:
In this type the bobbins or supply packages are placed on rotating frames.
As shown in the diagram, withdrawal of yarn takes place on the outside. From the inside the new bobbins are creeled up when the yarn is being drawn off.
When the outside bobbins exhausted, the frame is rotated and new bobbin pulled in.
The advantage of this creel is to reduce the stoppage time during the bobbin change.
Single end creel:
The same amount of yarn present on the creel package to produce an integral number of beams.
Single package is associated with each end being wound on beam.
It consists of truck creel and duplicated creel.
This is a readymade creel which is moved by wheels to take the position of the runout creel.
In truck creel, creel is variable and headstock is rigid. Which means the creel moves.
In duplicated creel, creel is rigid and headstock is variable. Which means the head stock moves.