Textile & Fashion World

High Speed Warping:

High speed warping also called Beam warping/Direct warping. In high speed warping the yarn is wound parallel on the warping beam. All the yarns are wound at once and simple flanged beam is used. It is a very high speed process and is used for making fabric of single colour.

Flow Chart of High Speed Warping

Features of High Speed Warping

1. It is used to make common fabrics in large quantities
2. It is used to produce weavers beam from single yarn
3. The production is high
4. Large amount of yarn is required to produce a weavers beam
5. Sizing is done
6. Simple flanged beam is used and drums are not required 

Sectional Warping

In sectional warping equal length of yarn is first wound in small sections or sheets on a drum. Then from the drum it is transferred to the beam. By this process we directly get the weavers beam. This is a two stage method and is used for making fancy fabrics.

Flow Chart of Sectional Warping:

 Working Principle of Sectional Warping:

1. Sectional warping is used for short runs especially for fancy pattern fabrics.
2. In this case sections of the warp which may contain up to 1000 ends are first wound onto a drum tapered with a given cone angle.
3. So cross wound sections are combined on the drum & thus each layer of warp contains the same number of ends on the drum.
4. Then the warp threads altogether are transferred onto a weavers beam by unwinding the drum.
5. In this method the warp threads are not necessarily processed in sizing.

Features of Sectional Warping

1. This is suitable for making checked, stripped or other fancy fabric.
2. We directly obtain weaver’s beam from this process
3. As sizing is not done, so multi-ply yarns or yarns which do not require sizing are used
4. Small amount of yarn is required to produce the weaver’s beam
5. Sectional warping is used to produce a warp beam with a greater member if ends
6. The production is less in sectional warping
7. The yarn tension is less uniform
8. It is less efficient than high speed warping

Differences Between Sectional and High Speed Warping

High Speed Warping	Sectional Warping
1. Beam warping is used for long runs of grey fabrics & simple pattern.	1. Sectional warping is used for short runs especially for fancy pattern fabrics.
2. The amount of colored yarn is less than 15% of the total.	2. Greater amount of colored yarn is used.
3. High production.	3. Low production.
4. Large amount of yarn required.	4. Small amount of yarn required.
5. Single yarn is used.	5. Twisted yarn is used.
6. Less expensive.	6. More expensive.
7. It is most widely used for cotton, linen, woolen & worsted yarn.	7. It is most widely used for silk & synthetic yarn.
8. Uniform tension of yarn.	8. Less uniform tension of yarn.
9. Weavers beam is produced after sizing.	9. Weavers beam is produced after warping.
10. Creel capacity is more.	10. Creel capacity is less.
11. Beam warping is more widely used.	11. Sectional warping is not widely used.

Warp Preparation

Drawing-In
Provides each warp yam with its drop wire, heddle, and reed dent.

Tying- In
When mass producing the same fabric by simply typing each end of a new beam to its corresponding end of the old beam

Necessity of Warp Yarn Preparation 
We need to prepare the warp yarn because of:

1. Imperfection of yarn.
2. Requirement to transfer the spun yarns in a conventional package.
3. Extra treatment to make the yarn ready for weaving.
4. Warp yarn must be able to withstand destructive forces to which it is subjected during the weaving process.
5. Yarn hairiness must be decreases.
6. Yarn must be aligned properly.
7. Yarn elongation & flexibility must be sustained.

Weft Preparation
On conventional loom the filling yarn is inserted by means of a shuttle carrying a bobbin. This bobbin should be tapered at the end so that the yarn may be pulled without interruption through the eye of the shuttle as the shuttle travels from one side of the loom to the other.

Necessity of Weft Yarn Preparation

1. Removal of slubs & weak places during processing which otherwise would impair the running of the loom.
2. The production of the tighter packages having more yards per pirn. This reduces the number of pirn changes in the loom. This, in turn, reduces the possibilities of flaws & wastage.
3. Greater uniformity of pirns used on the loom. This improves the uniformity of the fabric.
4. The easy handling of small lots. 

 

http://textilelearner.blogspot.com/search/label/Warping 

Warping
Warping is the parallel winding of yarn from cone or cheese package on to a warp beam.The operation of winding warp yarns onto a beam usually in preparation for slashing, weaving, or warp knitting. Also called warping.

1. Warp Winding: The main functions of warp winding are to rewind the yarns from the spinning frame or texturing machine in a long continuous length to suit later processes. This is a process to wind the yarns into a suitable package size and shape, and also to take out imperfections such as slubs, weak places, leaves, neps and dirt, which are always present in yarn as delivered from the spinning frame. The winding machines for warp preparation can be classified as follows:

A. Drum winder: The yarn package (cheese or cone) is frictionally driven by using a driving drum or roll. Either a cam traverse or a grooved roller makes the yarn traverse motion. Due to the surface driving of the yarn package, the yarn speed is always constant, independent of the package diameter.

B. Precision winder: This is a precise-traverse winder using a yarn guide, which is controlled by means of a traverse cam or a grooved roller. The yarn package is driven positively by using a spindle. Therefore, the yarn speed is increased according to the package diameter if the spindle speed is constant. This type of winder is used for continuous filament yarns that are unsuitable for frictional winding methods like the drum winder.

2. Warping (Beaming): The purpose of warping is to arrange threads in long length, parallel to one another as preparatory to further processing. The primary operation of warp-making in which ends withdrawn from a warping creel, evenly spaced in sheet form, are wounded onto a beam (known as warper’s beam) to substantial length. There are two warping methods, i.e. direct beaming and sectional warping.

A. Direct warping/beaming: This is the winding of total number of warp ends in full width in a single operation from creeled bobbin. Direct beaming /warping is used for long runs of greige fabric and simple patterns where the amount of coloured yarn involved is less than about 15 percent of the total.

B. Sectional warping: This is a method of preparing a warp beam consisting in i) winding a warp in sections on a reel/drum and ii) beaming-off the complete warp from the reel onto a warp beam. Sectional warping is used to produce warp beam for Yarn dyed fabric.

3. Sizing/Slashing: Sizing means the operation of applying a special solution (known as size solution) to warp yarns to strengthen, smoothen and lubricate them. In machine sizing a warp is transferred from a warp beam to a loom beam. The procedure is as follows:

• Warp in sheet form is withdrawn form a warp beam is passed through a sow-box and the squeezing rollers of a sizing machine. Application of size solution by immersion or by contact with a partially immersed roller, and penetration of the yarn by the size solution occur at this stage. The sizing agents generally used are PVA (Polyvinyl alcohol), Starch, Acrylic esters, CMC (Carboxymethyl cellulose), Wax etc.
• The warp is dried by hot air or by contact with steam-heated cylinders en route to the loom beam.

4. Looming: Looming covers the processes involved in warp preparation after sizing upto setting them to loom. During slashing, the exact number of warp yarns required in fabric is wound onto the loom (or weaver's) beam. The warp ends are then passed through the drop wires of the warp stop motion, the heddles of the harness frames and the dents at the reed. This can be achieved by drawing -in or tying-in, the choice depending upon whether or not the new warp is different from the warp already on the loom. The processes are as follows:

Drawing-in: The process of drawing every warp end through its drop wire, heddle eye and reed dent can be performed manually or by means of automatic machines. In both case, a length of warp yarn, just enough to reach to the other side of the frame, is unwound. Leasing (i.e. selecting warp) of the warp at this stage simplifies the separation of the yarns. Then they are threaded through drop-wires, heddle eyes and reed dents. The automatic drawing machine can handle the leasing-in and drawing-in process in single operation.

Tying-in: When fabric of a particular type is being mass-produced, the new warp beams will be identical with the exhausted beams on the looms. Therefore, if every end on the new beam is tied to its corresponding end on the old beam, the drawing-in process can be omitted. Tying-in may be done by means of a small portable machine on the loom or as a separate operation away from the loom. 

http://textilelearner.blogspot.com/search/label/Warping 

Defects & Remedies of Warping

1. Lapped end

Cause:
The broken end of yarn is not tied to the end on the warp beam & overlaps the adjoining yarn. The beam is not properly brake & the signal hook fails to operate.

Remedies:

• Tying the broken end to the end on the warp beam.
• Proper signal hook.

2. Piecing

Cause:
One broken end is pieced to another yarn end on the warping beam.

Remedies:

• By proper joining.

3. Soft ends on the warping beam

Cause:
Breakage of a group of ends & piecing them in bundle or by lapping. This defect is caused by the careless of the operator.

Remedies:

• Careful operation.
• Broken end should be piece up properly.

4. Incorrect form of build

Cause:
Caused by non uniform spreading of ends in the guide reed & its improper setting & conical winding in case of non uniform pressure of the warping beam.

Remedies:

• Uniform spreading of ends.
• Appropriate setting.

5. Slacks & irregular yarn tension

Cause:
It happens due to any one of these reasons- improper threading of the yarn into the tension devices, ejection of yarn from under the disc of the yarn tensioning device, or yarn tension devices of poor quality.

Remedies:

• Proper threading of tension device.
• Good quality of tension device.

6. Broken ends on the beam

Cause:
A group of ends is broken & tied as a brunch or worked-in with overlapping.

Remedies:

• Broken ends should be removed.

7. Conical winding on the beam

Cause:
It occurs due to incorrect load applied by the pressure roller.

Remedies:

• Correct load applied.

8. Improper length of warping

Cause:
It is due to malfunction of the counter & the brakes of the measuring device & warp beams.

Remedies:

• Good measuring device. 

 http://textilelearner.blogspot.com/search/label/Warping

The latest beam beam warping machines have a very simple design, which results in higher speed & consequently in output increase.

Main Parts Beam Warping Machine:

• Creel
• Expanding comb
• Pressure roller
• Beam

Working Principle of Beam Warping Machine:
In beam warping, the yarns are withdrawn from the single-end yarn packages on the creel & directly wound on a beam. Direct warping is used in two ways:

1. Beam warping can be used to directly produce the weaver’s beam in a single operation. This is especially suitable for strong yarns that do not require sizing such as continuous filaments & when the number of warp ends on the warp beam is relatively small. This is also called direct beaming.
   
2. Beam warping is used to make smaller intermediate beams called warper’s beams. These smaller beams are combined later at the sizing stage to produce the weaver’s beam. This process is called beaming. Therefore, for if the weaver’s beam contains 10,000 warp ends, hen there would be-say – 10 warper’s beams of 1,000 ends each. If this weaver’s were to be made an one stage, the creel would have to have 10,000 yarn yarn packages, which is impossible to manage. 

How to Improve Beam Warping Process?
Beam warping process is the most progressive process ensuring a high quality of produced warps & high efficiency. In cotton weaving, beam warping is mostly used.

1. Better uniformity in the tension of individual yarns are the provision of adjusting the tension of separate groups of warp yarns over the height of the warping creel.
2. Enlarging the mass of bobbins & warping beam winding.
3. Increased number of bobbins when warping yarn of low linear density & a greater number of yarns in the warp.
4. Improved shape of winding on the warping beams & uniformity of the specific density of winding.
5. Higher accuracy in warp measuring & reduction of wastes caused by irregular unwinding of warps from the beams at sizing.
6. Compensation of warp tension at starting & stopping of the machine & slow running at starting a new warping beam.
7. Increase of labor productivity in warping by partial or full automation of bobbin change. 

http://textilelearner.blogspot.com/ 

Identification of End (Warp) & Pick (Weft) :
Warp and weft yarns have different demands placed on them and may differ in their structure or fiber type. Thus, a fabric may not have the same performance characteristics for warp and weft. The warp must withstand the high tensions of the loom and the abrasion of weaving, so the warp yarns are stronger and more uniform with higher twist. Filling yarns are more often fancy or special-function yarns such as high-twist crepe yarns, low-twist napping yarns, or boucle yarns. We can define end and pick in the following way.

End:
1. An individual warp yarn. A warp is composed of a number of ends. 2. An individual sliver, slubbing, roving, yarn, thread, or cord. 3. A short length or remnant of fabric.

Warp (End) and Weft (Pick)

Pick:
In a woven fabric, the yarn running from selvage to selvage at right angles to the warp. Each crosswise length is called a pick. In the weaving process, the filling yarn is carried by the shuttle or other type of yarn carrier. The picks interlace with the warp ends to form a woven fabric.

Identification of End & Pick: 

Differentiating between warp and weft is possible by carefully examining both the fabric and the length-wise and crosswise yarns.

1. Most fabrics have lower elongation in the warp direction.
2. The warp yarns lie straighter and are more parallel in the fabric because of loom tension.
3. Fancy or special-function yarns are usually in the filling direction.
4. Fabric crimp is usually greater for weft yarns since they must bend or flex over or under warp yarns due to the way the loom operates.
5. Fabric characteristics may differentiate between the warp and weft directions. For example, poplin has a weft rib and satin has warp floats.
6. The selvedge always runs in the lengthwise (warp) direction of all fabrics.
7. Warp yarns tend to be smaller, are more uniform in structure and appearance, and have higher twist.

http://textilelearner.blogspot.com/search/label/Warping 

Independently of the warping system, the threads are fed from bobbins placed on creels. The creels are simply metallic frames on which the feeding bobbins are fitted; they are equipped with yarn tensioning devices, which in modern machines are provided with automatic control and centralized tension variation. Moreover the creels are equipped with yarn breakage monitoring systems . The creel capacity is the parameter on which the number of warping sections or beam s depends; it should be as high as the installation type and planning permit; the usual creel capacity amounts today to 800-1200 bobbins. Various solutions have been designed to reduce the time required to load the creel and thus increase the warping performance . 

When standard creels are used, the most costeffective solution is, provided that there is sufficient room available, to use two creels for one and the same warping machine; in fact, while one of the two creels is used for warping, the other creel can be creeled up again. In this case it is advisable that the reserve creel is equipped with comb holder and that the warp threads are already drawn through the dents of the combs. This way the loss of time caused by creel change can be minimized.

Types of Creel

Mobile Creel: this creel type is similar to the standard creel, but is formed by trolleys which can be
taken individually out of the creel. The bobbins are creeled up on each trolley outside the creel. During the
creeling up of a series of trolleys, the second series of trolleys is brought back to the outside of the creel to
feed the warper. This reduces considerably the waiting time. The mobile creel comes in handy especially when
there is insufficient room to permit the use of two standard creels.

Magazine Creel: this kind of creel is used when several warps of similar type must be prepared in
sequence, that is when large lots of similar yarns need to be processed. Level with each tensioner, two bobbins are positioned: one operating and the other as reserve. 

Swivel Frame Creel: this type of creel was designed as a variation of the mobile creel to enable the creeling up of bobbins which, owing to their heavy weight (5 to 25 kg), cannot be pinned on trolleys. Each bobbin holder is double-sided: the threads are unwound from one side, while a new series of bobbins is creeled up on the other side.

V-shaped Creel: In this creel type, the creel boards are assembled in form of endless chains. While
warping is carried out from the outer sides using the already creeled up bobbins, the subsequent yarn lot can
be creeled up on the empty spindles positioned inside the creel. This interior room serves at the same time as
storage and bobbin exchange station. The yarn lot can be changed by simply pushing a button, which starts the electrically drive of the chains. The empty bobbins move towards the inside of the creel, the full bobbins towards the outside.

http://textilelearner.blogspot.com/