YARN WAXING


It is common practice to wax staple-spun yarns for knitting applications, given the problems of friction associated with the many thread line deflection points of the thread guides and the knitting needles on knitting machines. For optimal running of yarns during knitting, there needs to be a uniform wax distribution along yarns and a minimum of wax rub-off.

The amount of wax deposited on the yarn has a marked influence on the dynamic frictional characteristics of the yarn. Figure 1a shows that, at a given running speed, the yarn coefficient of friction decreases to a minimum with increasing wax deposited and then increases with further yarn waxing. Of the three zones indicated, clearly, Zone II is the preferred range of deposition, usually 0.5 to 1.0 g/kg of yarn. Wax grades vary according to melting point, oil content, microstructure, and hardness. Little has been published in the way of selecting a wax grade for optimal running performance. However, it would seem that selection depends on many factors such as fiber type; yarn structure, count, and moisture content; as well as room temperature and humidity in the winding area and during storage and shipment.

The preference with the commonly used wax disc is for a coarse microcrystalline structure, which allows small wax particles to be removed and held onto the yarn surface as shown in Figure 7.17b, as this should enable a uniform distribution of deposition. Steaming or high-humidity conditioning of wax yarns can result in an increased friction coefficient. Steaming will melt the wax particles and also give a partial penetration of wax into the yarn. If the yarn has to be relaxed in this way, then the deposition should be increased to offset the effect.

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FIGURE 1 Yarn thread line friction with increased wax take-up. (Courtesy of W. Schlafhorst AG & Co.)

Principle of Winding Machine


There are two widely used types of winding machine:

1.) drum winders (used to wind staple-spun yarns into random-wound packages)

2.)precision winders (for winding filament yarns into precision-wound packages).

1.) drum winders

They are also called as “Random Winders”. Drum-winding machines rotate the forming package through surface contact with a cylindrical drum, and the yarn is traversed either by an independent traverse, typically a wing cam, or by grooves in the drum. Figure  1   illustrates the two types of traverse systems

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Fig 1: Winding traverse motion

  • Wing Cam

There are several different independent traverse systems, but the simplicity of the wing cam makes it a useful example to describe. As shown, the end, A, of a yarn guide bar moves the yarn while the other, B, is made to move around the periphery of the cam, traveling one circuit of the periphery per revolution of the camshaft. As B makes one circuit of the cam, A reciprocates, moving the yarn through a return traverse (i.e., double traverse) along the length of the bobbin. The reciprocating yarn guide limits the winding speed because of the inertia on reversals. A very high rate of traverse is impeded by the mechanics of the guide system, since forces of 16 to 64 times the weight of the yarn guide can be present during the reciprocating action. The reciprocating guide can be replaced by a spirally grooved traverse roller, which moves the yarn along the traverse length. In this case, only the yarn undergoes reversal as it is held in the traversing groove of the rotating roller, and speeds in excess of 1500 m/min can be achieved. A further advantage of the grooved traverse roller is that, as a result of tension, the yarn being wound enters the groove without the need for threading up as is required with the independent traverse system.

  • Grooved Drum

With the grooved drum system, the surface speed of the drum, and the traverse speed are kept constant. A continuous helical groove (i.e., interconnected clockwise and counter clockwise helical grooves) around the drum circumference guides the yarn along the traverse length as the yarn is wound onto the bobbin. A continuous helix has points of crossover of the clockwise and counter clockwise helices. To retain the yarn in the correct groove during its traverse, particularly at the intersections, one groove is made deeper than the other, and the shallower groove is slightly angled.

2.)precision winders

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They are also known as Spindle driven Winders. the Principle of precision winder is as shown in figure.

With precision winders, the package is mounted onto a drive spindle, and a reciprocating yarn guide, driven by a cylindrical cam coupled to the spindle drive, is used to move the yarn along the traverse length. The reciprocating yarn guide limits the winding speed because of the inertia on reversals.

The term precision refers to the control of positioning each layer of yarn as it is wound onto the bobbin. There is a precise ratio of spindle to traverse speed. Therefore, as the package diameter increases, the wind and TR are kept constant.

Choosing the best package variable


The variables in package construction are :

a) Cone taper

The steeper the cone taper the greater the freedom of yarn withdrawal and therefore a reduced tendencies to peak tension. But as the cone angle is increased there is a strong possibility of slough off at high unwinding speed  So proper selection of taper must be made for the end use.

e.g. In knitting the winding speed is slow .and uniform and yarn should be capable of being unwound at low tension. Hence a steeper cone angle may be suitable.

For selecting best taper, cones with different taper should be wound and should be unwound under similar conditions as it s end use the taper that gives minimum stops due to slough off and peak tension is the best paper for that end use.

B: Package length and diameter:-

For optimum continuity of yarn supply in the subsequent process to winder one would think to go for longer package with grater diameter. so tests are conducted in which packages are wound with different package length and diameter combinations. they are then unwound under similar conditions of the subsequent process and the unwinding characteristics is studied. The package length and diameter range(empty PKG to full PKG) that gives the best unwinding characteristics such as uniform unwinding tension,minimum tension picks, slough off should be selected.

C:-winds per(single) traverse.:

The characteristic of package mainly by the change in winds per double traverse are:

1package density

2:package stability and characteristics such as tension peaks,slough off etc.

the no of winds per single traverse for a given package length decides angle of wind with law wind the angle is more and visa versa. Low wind means less coils in each layer.

In winding a dye package few wind is used to get openness required for easier and free flow of dye liquid.

For knitting purpose relatively low wind should be used. low wind gives higher coil angle and the degree of yarn across face of package is minimized so yarn unwinding at low tension becomes possible.

Knotting


Among the various types of knot, the weaver’s knot and the fisherman’s knot, illustrated in Figure 1, are the two types that may be used. The latter is suitable for most yarns. The weaver’s knot is more appropriate for short-staple yarns, as it is a smaller knot, but it slips more easily when under tension.

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FIGURE  1:-Fisherman’s and weaver’s knots.

The advantage of a knot is that its strength will be several times that of the yarn strength so, if properly tied, it gives reliability to the piecing. However, the knot has many disadvantages for the end user of the yarn and may be seen as “one fault replacing a worst fault.” Its main drawback is size, i.e., its thickness and tails. The weaver’s knot is two to three times the yarn thickness; the fisherman’s knot is three to four times as large. Often, therefore, it may be preferable to accept a thick place in the yarn as a compromise on the final fabric quality, even if it is of comparable thickness, since no tail ends will be present and, as it is less firm than the knot, it could be less visible in the fabric. In processes subsequent to winding, knots can be problematic. When passing at high speed through a tension device (e.g., a disc tensioner), a knot can give rise to a sudden high peak tension, causing a yarn break. Although smaller and hence preferable for finer yarns, the weaver’s knot is susceptible to untying when tensioned. In weaving, then, the alternating stresses on the warp yarn can cause slipped knots, especially with plied yarns. With densely woven fabrics, knots and tails can rub neighboring warp ends, hampering shedding and causing yarn breaks. The size of the knot can disturb weft insertion on air-jet looms, leading to fabric faults, and, in knitting, difficulty in passing a knot through needles can cause holes in the fabric because of dropped stitches or needle breaks.

The development of the splice has made a major reduction in the size of pieced ends and has therefore eliminated many of the processing difficulties mentioned above and greatly improved fabric quality. Consequently, splicing is seen as the industry standard and, although not all spun yarns can be spliced, the great majority of winding machines are fitted with automatic splicers.

SIZING


The primary purpose of sizing is to produce warp yarns that will weave satisfactorily without suffering any consequential damage due to abrasion with the moving parts of the loom. The other objective, though not very common in modern practice, is to impart special properties to the fabric, such as weight, feel, softness, and handle. However, the aforementioned primary objective is of paramount technical significance and is discussed in detail herein. During the process of weaving, warp yarns are subjected to considerable
tension together with an abrasive action. A warp yarn, during its passage from the weaver’s beam to the fell of the cloth, is subjected to intensive abrasion against the whip roll, drop wires, heddle eyes, adjacent heddles, reed wires, and the picking element, as shown in Fig.1 . The intensity of the abrasive action is especially high for heavy sett fabrics. The warp yarns may break during the process of weaving due to the complex mechanical actions consisting of cyclic extension, abrasion, and bending. To prevent warp yarns from excessive breakage under such weaving conditions, the threads are sized to impart better abrasion resistance and to improve yarn strength. The purpose of sizing is to increase the strength and abrasion resistance of the yarn by encapsulating the yarn with a smooth but tough size film. The coating of the size film around the yarn improves the abrasion resistance and protects the weak places in the yarns from the rigorous actions of the moving loom parts.

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Fig 1:- Parts of the loom and major abrasion points.

The functions of the sizing operation are
1. To lay in the protruding fibers in the body of the yarn and to cover weak places by encapsulating the yarn by a protective coating of the size film. The thickness of the size film coating should be optimized. Too thick a coating will be susceptible to easy size shed-off on the loom.

2. To increase the strength of the spun warp yarn without affecting its extensibility. This is achieved by allowing the penetration of the size into the yarn. The size in the yarn matrix will tend to bind all the fibers together, as shown in Fig. 4.18. The increase in strength due to sizing is normally expected to be about 10 to 15% with respect to the strength of the unsized yarn. Excessive penetration of the size liquid into the core of the yarn is not desirable because it affects the flexibility of the yarn.

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Fig2 : -Fiber–size binding in a yarn (not to scale).

3. To make a weaver’s beam with the exact number of warp threads ready for weaving.

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Fig.3 Schematics showing size distribution; (a) too much penetration, no surface coating; (b) too much penetration, more size added to provide surface coating; (c) too little penetration, no anchoring of yarn structure; (d) optimal distribution.

Figure 3 illustrates various possible conditions that may occur in practice depending upon the properties of the size employed. This emphasizes the importance of an optimal balance between the penetration of the size into the yarn and providing a protective coating around the yarn, as shown in Fig. 3d. The flow properties of the size liquid and the application temperature have important effects on the distribution of the size within the yarn structure. More size at the periphery of the yarn will tend to shed off on the loom under the applied forces because the size is not well anchored on the fibers. Too much penetration, as shown in Fig. 3a, may leave too little size around the yarn surface to protect it against the abrasive action. To rectify such a condition, a higher size add-on is required to provide the required protective surface coating.

END PACKAGES PRODUCED ON WINDING M/CS


Most of the common packages on which the yarns are wound can be divided in to two groups.

(1)Parellal wound packages

(2)Cross wound packages.

(1)Parellal wound packages:-

These are double flanged bobbins,also known as warper’s bobbins on which yarn is wound in such a way that the coils of yarn are laid parellel sided or barrel shaped,Flanges are needed on either sides to support parellely laid coils.If flanges are not provided then coils at the two ends will COLLAPSE.  To withdraw the yarn from these packages,package has to be rotated by pull of yarn.Hence high unwinding speed will lead to excessive unwinding tension & yarn will break.Also as the unwinding is stopped the package continues to rotate due to its inertia,hence yarn may continue to come out from package.So this package is not suitable for the process taking place at high speed.

(2)Cross wound packages:-

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In this case the yarn is wound on cylindrical tubes or conical tubes.The yarn is laid on this in form of helices at the two extremes. In this type of winding the yarn wraps cross one another hence these packages are called cross wound packages.Because of laying in cross fashion there is no possibility of yarn coils collapsing at the two extremes.Hence these packages do not need flanges. The cylindrical cross wound package is known as CHEESE & the conical one as CONE. The yarn can be withdrawn from cone & cheese overend (& side ways unrolling also).The over end withdrawal allows unwinding at high speed without extreme increase  in tension.Rotation of package for unwinding is not essential hence the unwinding from package stops almost at the same instant when withdrawal is stopped. For some special cases yarn is required to be withdrawn side ways also.

Bobbins may be made of card or plastic, the latter being perforated if the yarn is to be package dyed. Parallel-sided cheeses have tubular bobbins. For cones, the bobbin is of a conical form, i.e., a truncated cone; the angle of taper — the semivertical angle — depends on the end use for the resulting package. Table 1 lists four common tapers. The wound cone package may have a fixed taper, which gives it flat ends, in which case the package is referred to as straight-ended. Cones may also have an accelerated taper, where the taper of the package is greater than the bobbin, resulting in a concave end at the top (the nose) and a convex end at the bottom (the base) of the package. These are called dished ends.

Table :- Common Tapers for Random-Wound Cones

Cone taper
(semivertical angle)
End uses
3°30′ General purposes
4°2′ Wet processing (e.g., dyeing)
5°5′ Weft knitting: at final diameter taper may increase to 10°
9°1′ Weft knitting: at final diameter taper may be 14° to 18°

Comparison of cross and parallel wound package

Sr no. Cross wound Package Parallel wound package
1 Self supporting Package Flanges are required to support the yarn
2 Overhead Unwinding Side-end Unwinding
3 Package is Stationary during unwinding Package rotates during Unwinding
4 The yarn stops immideatly the unwinding Stops The yarn doesnot stop unwinding as the  package continues to rotating due to inertia
5 Suitable for High speed unwinding Not suitable for high speed unwinding
6 yarn is laid at an angle to each other The yarn is laid parallel to one another
7 eg., Warper’s Bobbin Eg, Cone, Cheese & Spool

Yarn Preparatory process


The yarn is received from spinning department in the form of ring frame bobbins or hanks to make it usable on loom it must be converted into suitable form i.e. wrap & weft as discussed earlier.

These intermediate process between spinning & weaving on loom, which converts the yarn in suitable form that can be used for weaving, are called Weaving Preparetory Process.

The process used in the manufacture of WRAP & WEFT are called ‘ Wrap Preparatory Process’ & ‘ Weft Preparatory Process’ respectively.

Wrap Preparatory Process

The process to be used depend upon the type & quality of yarns, the type of fabric to be produced, & also on the equipment & other facilities available in the mill. The process flow chart is given below which shows the various stages of wrap preparation. The solid lines indicate the basic process most commonly used & the dotted lines indicate some additional processes required for different types of fabrics.

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Windings : In the process, the yarn from a number of ring frame bobbins or hanks is put in a long continuous length on to a bigger packages such as Wraper’s bobbin, cone or cheese. During this process, the objectionable faults are removed from yarn. For the use of dyed yarn, ring frame bobbins may be taken to reeling process to obtain hanks. These hanks are dyed 2 & then sent to winding. The yarn is dyed in cone/cheese form also. Thus, winding packages ( wrapers’ bobbin, corn or cheese ) are taken to next process of wraping i.e. Direct Wraping or Sectional Wraping.

Wraping :

( DIRECT WRAPING OR BEAM WRAPING )

The object of wraping is to collect a predetermined number of single end packages (winding package from which a single thread comes out on unwinding) & convert it into sheet form with ends uniformly spaced & wind a specified length on to wraper’s beam. Thus at the end of process, we get a multiend package (package which on unwinding give no. of ends) i.e. wraper’s beam wound with a sheet of uniformly spaced (hundreds of) ends of specified length. To have a sheet, the wraper’s beam is subjective to dyeing to get dyed wrap.

( SECTIONAL WRAPING AND BEAMING )

Sectional wraping consists of winding of wraping of number of sections, each wound with a (narrow) sheet of uniformly spaced, predetermined number of ends of equal length side by side. on collecting ends from all sections, we get required number of ends required for weaving. Beaming consists of winding sheet, obtained by collecting ends from al sections, on weaver’s beam. Thus, at the end of the process, we get weaver’s beam which may be sent to loom or for drawing-in.

Sizing: Wrap thrads are subjeced to considerable stresses, strains & rubbing action duration weaving. So wrap threads are impregnated with size whose main constituent is on adhesive substance. The size binds the fibres in the yarn surface to resist stresses, strains & rubbling action without breaking. At the back of sizing machine, wrap sheets form number of wraper’s beam are combined to obtain a single sheet containing required number of ends for weaving. This sheet is impregnated with size, dried & wound on weaver’s beam. Thus, at the end of sizing, we get weaver’s beam which may be sent for drawing in or to loom.

Drawing-in & denting :- This process consists of passing ends of wrapsheet from weaver’s beam through heald eyes of healdshaft & throught dents of reed. On loom, if exactly the same fabric is to be prodused after a weaver’s beam is exhausted, then the new sheet of wrap threads is connected end by end to the old sheet. This operation is called tying-in or twisting depending upon the method of joining. Thus, this process need only weaver’s beam wound with wrap. But if other type of fabric is to be prodused after a weaver’s beam is exhausted, then we need weaver’s beam with wrap drawn & dented. Old beams with its heald shafts & reed is removed & new beam is & heald shafts & reed reset on the loom.

Wrap Preparatory Process

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The processes of Reeling,Hank dyeing,Winding & cone/cheese dyeing are same as discussed earlier.The end package of weft ring spinning frames are directly used in the shuttle.This type of weft is known as direct weft.The yarn from ring frame bobbins is subjected to Winding/Cone or Cheese dyeing.The yarn from bigger packages(Cone/Cheese or Warper’s bobbin) (from which objectionable faults are removed/may be dyed too) is wound on to pirns by means of pirn winding.These pirns are supplied to shuttle looms.

The winding packages(Cone/Cheese) are supplied to Automatic Shuttle Looms fitted with Unifil loom winder or to shuttle looms(such as gripper,air jet,water jet or rapier).

Quality requirements of Warp and Weft in weaving


TO CARRY OUT WEAVING MOST PROFITABLE, THE AIM SHOULD BE:-

– For maximum production (per loom and per operative).

– For best quality.

– To achieve this quality of warp and weft should be good. Poor quality of warp and weft causes frequent breakages. So loom has to be stopped frequently which badly affects productivity. Poor quality of warp and weft can lead to production of fabric with inferior quality. SO FOR THE BEST RESULT IN WEAVING , THE BEST QUALITY OF WARP AND WEFT IS THE MUST.

 WARP:-

1. To produce fabric of uniform quality, the tension of warp threads across the width should be same i.e if there are 500 ends, tension of all of them should be same. Similarly the tension of warp sheet as it is unwound from weaver’s beam should also be same.

2. The end should be free from any place that can cause breakage during weaving or can give bad appearance to the cloth. E.g.

(a)A weak place can cause breakage during weaving.

(b)A thick place can cause breakage and give bad appearance.

(c)A thin place can cause bad appearance. Particularly thinner place continuing over a long distance, say 1 or 2m will give bad appearance, as in that portion a fine crack like appearance may be seen.

3. During weaving warp threads are kept under considerable tension and are subjected to the abrasive action of the healds, other moving parts and also of the neighbouring threads of warp. The warp threads should be strong enough to resist these actions without breaking.

WEFT

The weft is supplied to weaving by using any of the following,

(a) For shuttle looms weft is wound on pirns. The pirn fits in to a shuttle. The shuttle is projected into the shed. So supply of weft is in the form of pirn wound with weft.

(b) For shuttle looms fitted with “UNFIL” loom winder, pirn winding is done by a special mechanism on loom itself. So supply of weft is in form of cones or cheese.

(c) For looms in which insertion of weft is not by shuttle carrying pirn are called shuttle-less looms. In these looms (generally) weft insertion takes place from one side of the loom. The weft is withdrawn from the packages such as cones or cheeses and it is inserted into the shed by some carrier (gripper, rapier or air jet or water jet).

As Stated above pirn or cone or cheese can be the package of weft supply. Here also the unwinding tension should be as uniform as possible to produce the fabric of uniform quality and also any factor, such as slough off, entanglement etc., that can cause breakage of weft, should be taken care off. The weft thread should be free from weak places, thick places, thin places, etc., that can cause breakage or give bad appearance to the fabric

Preparation of weaving machines


To obtain satisfactory weaving performance, it is essential to have not only a correct yarn preparation, but also an efficient organization which permits to have warps available at the right moment, thus avoiding any dead time with style or beam change. All these prerequisites aim at ensuring to the weaving mills a sufficient flexibility and at permitting them to cope promptly with a variable market demand.

Currently several weaving mills have installed weaving machines which enable to perform the quick style change (QSC), leading to a considerable reduction of the waiting time of the machine.

The following chart presents the possible alternatives for the preparation of the weaving machine:

Changing style means producing a new fabric style, weaver’s beam changing means going on weaving the same fabric style just replacing the empty beam with a full beam of same type. Drawing-in consists of threading the warp yarns through the drop wires, the healds and the reed (fig.1). Depending on the styles of the produced fabrics and on the company’s size, this operation can be carried out manually, by drawing-in female workers operating in pairs (a time consuming activity which requires also skill and care), or by using automatic drawing-in machines.

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Fig. 1− Drawing-in

Fig. 2 shows one of the most established heald drawing-in machines. The drawing-in begins by placing the weaver’s beam, the harness and the row of healds on the proper anchor brackets, then the drawing-in program is typed in on the computer and the machine is started. A sort of long needle picks up in sequence the threads and inserts them with only one movement into the drop wires, the healds and the reed dents, which are selected each time and lined up to that purpose. The computer controls the different functions and supervises them electronically, ensuring the exact execution of the operation and interrupting it in case of defects. The machine can be used with the usual types of healds, drop wires and reeds and can process a wide range of yarn types and counts, from silk yarns to coarse glass fibre yarns. The drawing-in speed can in optimum conditions exceed 6,000 threads/hour.

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Fig 2.: Heddle drawing-in machine

Fig. 30 presents another automatic drawing-in machine which carries out same functions as previous machine, however without needing the weaver’s beam. In fact it is fed by a common cotton twine which it inserts among the various elements of the warp stop motion, of the harness and of the reed according to the program set up on the computer and under its control and supervision. At the end of the drawing-in, the drawn-in devices are moved on the frame of a knotting station in which an automatic warp tying-in machine joins the drawing-in threads together with the threads of the beam. This operation can be made also on board the loom.

Fig 3:- Automatic drawing-in machine (Staubli KK / Korea Branch)

This machine offers the advantage of working always under optimum operating conditions (use of same yarn), independently of the quality of the warp to be prepared and in advance in respect to warping, therefore with higher flexibility. The drawing-in rate can reach 3600 threads/hour. Fig.4  shows a harness and a reed with already drawn-in threads, ready to be brought to the knotting station.

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Fig. 4:-  A harness and a reed with drawn-in threads ready to be moved to the knotting station.

The piecing-up of the warp yarns (Fig. 5) permits to the weaving mills which are in a position to use it (not many mills at the moment) to simplify and speed up considerably the loom starting operations in case of warps which were drawn-in or tied-up outside the weaving machine. The warp threads are laid into a uniform layer by the brush roller of the piecing-up machine and successively pieced-up between two plastic sheets respectively about 5 cm and 140 cm wide, both covering the whole warp width.

The plastic sheet can be inserted into the weaving machine simply and quickly, avoiding to group the threads together into bundles; the threads are then pieced-up on the tying cloth of the take-up roller.

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Fig. 5 − Piecing-up

If a new drawing-in operation is not necessary (this expensive operation is avoided whenever possible) because no style change is needed, the warp is taken from the beam store and brought directly to the weaving room, where it is knotted on board the loom to the warp prepared with the knotting machine.

As an alternative to the usual knotting on board the loom, the knotting outside the loom or stationary knotting of a new warp with an already drawn-in warp can be carried out in the preparation department. The devices bearing the threads of the old warps are taken from the weaving machine and the knotting can be started in the preparation room under better conditions, leaving the weaving machine free for rapid cleaning and maintenance operations.

The stationary knotting, in particular, takes place in following stages:

• Taking out of the loom the prepared beam with the harness
• Transport of the beam into the weaving preparation department
• Fastening of the heald frames and of the reed on the proper frame
Knotting
• Passing of the knots by proper drawing
Warp piecing-up
• Temporary maintenance of the new warp with the harness
• Transport of the new warp inclusive of harness with proper carriage
• Loading of the weaving machine and start of the weaving process using plastic sheet (fig.7)
• Weaving

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Fig. 6 − A knotting machine in operation on a warp with colour sequence, tensioned on the proper frame.

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Fig. 7 − Harness loading in the weaving machine

The automatic knotting machines can process a wide range of yarn types and counts at highly reliable and rapid operating conditions (up to 600 knots/minute), with mechanical or electronic control on double knots and on the sequence of warp patterns in case of multi-coloured warps. Fig. 6 shows a knotting machine in operation on a warp with colour  equence, tensioned on the proper frame.

Sample Warping


This warping process, which was developed for sampling purposes, gives full proof of its performances during this production phase of new items. This particular process is composed of several warping operations which wind up a limited thread length and place on the warping width several bands of different colours to get the colour variants of the fabric. This kind of warps can be obtained also by section warping, which however involves a considerable loss of time owing to frequent cone changes and definitely higher investments in raw materials. In practice a cone per colour is sufficient to obtain any required warping sequence. The machine is composed of a small creel where the cones of the warping sequence are placed, by a thread guide which winds up a preset number of meters (selectable with a pattern or a control device) taken from the cone according to the thread sequence in progress. The latest solution with revolving creel permits to wind up to 12 threads at a time at a winding speed of max. 1200 meters/minute. Once the winding operation is concluded, the threads are beamed on a weaver’s beam which follows the usual production cycle. The machine manufacturers proposed initially two solutions for this kind of warpers: the first solution envisaged a vertical development of the winding blanket, whereas according to the latest solution the threads are pre-wound on a drum before being wound on the weaver’s beam. The warp length in this last model varies from 7 to 420 meters; some weavers consider this length as normal for their productions and therefore use this system side by side with the traditional sectional warping machine. It is evident that the correct use of this machine permits to feed the weaving machine in a very short time while minimizing the use of materials and labour, especially if an automatic drawing-in equipment is available upstream.