What is Fancy Yarn?
Textile yarns are the basic elements of fabrics. For fabric design and production, yarns are mainly considered in terms of their colors, structures and material properties. Colors and the structure of yarns contribute to the fabric texture, covering power, luster and thickness. The term ‘fancy yarns’ may be taken to cover all fancy and novelty effects, while ‘fancy doubled yarns’ covers yarn and fiber effects. Color effects and effects based on metallic components are also available. Fancy yarns that are designed mainly for their aesthetic appearance rather than performance. Many fancy yarns achieve deliberate variation in appearance by the way of color. To be more inclusive, fancy yarns may be defined as any yarn that contains deliberate variation either in the form or in color, or both. The word deliberate is very important here because all yarns made from staple fibers are inherently variable due to the imperfection of the yarn spinning systems and the nonuniformity of fiber material.
In the production of normal regular yarns, efforts are made to minimize these variations so that the eventual fabric uniformity and performance properties such as strength and abrasion resistance are maximized. In fancy yarns, however, the variations are introduced by design to enhance the aesthetic appearance. These yarns provide the fabric designer greater scope in achieving a more attractive and exclusive product, but also pose greater challenges as they usually suffer from poorer performance and higher costs. Fancy yarns structures are manifested in terms of irregularities of curvatures of the central yarn axis and changes in the diameters of cross-sections in the yarns. The fancy yarn gives a fancy touch to the fabrics to a broad range of end uses. Significant demand for the fancy yams is the ladies and children outerwear.
The basic structure of a fancy doubled yarn consists of ‘core’ threads, an ‘effect material’, and a ‘binder’ which, as the name suggests, ensures that the entire structure holds together.
Different Types of Fancy Yarns:
It would be a futile attempt to try to describe all the varieties of fancy yarns, as these are designed to differ by definition. From the point of how the variation is introduced in the yarn, fancy yarn effects may be broadly divided into two categories:
- Fiber effect and
- Yarn effect.
Fiber effects are introduced prior to the formation of yarn; yarn effects are introduced by combining two or more yarns after the individual yarns have already been made. The two categories can obviously be combined to make more complex effects.
1. Fiber Effects:
Fiber effect fancy yarns are created during the spinning processes prior to the formation of the final yarn. These yarns are characterized by varying sizes of fiber lumps along the yarn length. Depending on the size of these fiber lumps, these fiber effects are often further divided into three subcategories: nepp, slub, and flake.
Nepp yarn, or nupp yarn, has a compact yarn structure with specks of fiber clusters distributed along the base yarn structure. Figure 1 shows an example. These yarns are most effective when the effect fibers have contrasting colors to the base yarn fiber, whereas more subtle effects can be created when the effect fiber and the base yarn have similar colors. The distribution of the effects should generally be random to avoid the moire effect as shown in Figure 1.
The production of nepp yarns are usually achieved during the preparation of fibers. The most widely used method is mixing prepared fiber balls such as wool nepps into the main fiber stock before carding. The fiber effect can be varied by the mixing ratio and the card setting, in addition to the usual yarn parameters of linear density and twist.
If the card settings are closer, these fiber balls will be opened up into smaller clusters and the effects will be smaller but more frequent; conversely, if the card settings are more open, these fiber balls will have larger and looser but less frequent effects. Due to the more vigorous actions of cotton cards, nepp yarn material is not normally prepared using the cotton card; otherwise, the fiber balls will mostly be opened up and the effects will be lost. From a performance point of view, larger effects, relative to the base yarn linear density, and effects in a looser and softer yarn structure with low twist level will have lower resistance to abrasion and the effects can be more easily rubbed off during fabric production and subsequent end use.
Slub yarns are more pronounced effects compared with nepp yarns. Figure 2 shows an example of slub yarn. These are more commonly produced during processes after carding but prior to the formation of the final yarn. These effects can be formed by introducing additional fibers into the fiber stream in a controlled manner or by introducing deliberate unevenness into the fiber flow. The introduction of additional fibers can be carried out during drafting in the spinning process or during condensation in the woolen process.
Unevenness can be introduced by varying the drafting roller speed in traditional ring spinning. It can also be introduced by deliberately creating local mechanical faults in machine components in a spinning system, such as the opening roller of a rotor spinning system. It is also possible to exploit the fact that fibers of dramatically different lengths tend to cluster during roller drafting, so mixing these fibers together before drafting and during drafting, the shorter fibers tend to cluster together to form slubs.
Flake yarns contain larger and usually looser fiber clusters than slub yarns. These yarns are sometimes also called flamme yarns. Figure 3 shows an example of flake yarn. In many ways, flake yarns may be considered as more pronounced slub yarns, but these effects can only be created by controlled introduction or injection of additional fibers into the fiber stream before spinning.
2. Yarn Effects:
Yarn effects are also sometimes called ply effects, as these effects are created by plying two or more yarns together subsequent to the production of the single yarns. These yarns can mostly be created using the traditional ring spinning system but with additional feeding and control devices, and more recently with the hollow spindle system. These fancy yarns always contain at least two basic component yarns: the ground or core and the effect. In the majority of cases, an additional component, binder yarn, is also required to fix the effect yarn on to the ground yarn. In reality, the variety of fancy yarns is unlimited, but based on the fundamental yarn structure, they can be classified into a few basic types. It is also possible to use knitting, braiding, or other techniques to make thin strands and use them as yarns. These types of fancy yarns are excluded here.
Marl yarns are probably the most simple plied yarn structures. These are effectively straight folded yarns made by plying two, and sometimes more, yarns together. The individual component yarns are usually exactly the same in linear density and twist but often differ in color or texture or both. The folding of these yarns creates a final yarn with subtle color or texture variation. A typical use of marl yarns is men’s suiting fabric to create a pinstripe effect. Figure 4 shows an example of a marl yarn with three component yarns. If any of the component yarns differ in linear density or twist, yarn structure variation will occur and the final yarn will be unbalanced, although it may be a designed outcome.
Spiral or corkscrew yarn:
The basic spiral structure is formed by plying two yarns together so that one yarn spirals around the other as shown in Figure 5. Spiral yarns are also called corkscrew yarns due to their appearance. This structure differs from the marl yarn in that one component yarn has a longer length than the other, and the shorter component yarn remains substantially straight.
Spiral yarns can be produced with one component yarn being fed faster than the other, requiring special overfeeding devices, which are described later in this chapter; they may also be made by simply plying yarns with differing linear densities but with the same feeding speed. In this case, no special feeding devices are required. Although the two component yarns have the same length during feeding, once plied, the two yarns will have different lengths depending on the ply twist direction. If the ply twist is in the same direction of the thick yarn twist, the thick yarn will contract, leading to a final yarn in which the thin yarn spirals around the thick yarn; if the ply twist is in the opposite direction of the thick yarn twist, the thick yarn will lengthen, leading to a final yarn in which the thick yarn spirals around the thin yarn.
A gimp yarn consists of at least three component yarns—the core, the effect, and the binder—and is produced in two stages. In the first stage, the core and the effect, which is usually overfed, are twisted together, producing an intermediate yarn similar to a spiral. In the second stage, the intermediate yarn is twisted together with the binder yarn with a twist that is opposite in direction to the twist used in the first stage. This reverse binding process removes most of the first stage twist. This leads to the effect yarn forming wavy projections on the yarn surface, and these projections are secured onto the core yarn by the binder yarn. The basic structure of a gimp yarn is illustrated in Figure 6.
Although it is common to overfeed the effect in the first twisting stage, this is not essential. When the effect yarn is much thicker than the core yarn, which is often the case to emphasize the wavy effect, it is possible to produce a spiral effect without the specialist overfeeding device. Reverse binding this spiral yarn can also produce a gimp yarn with more subtle wary projections.
An eccentric yarn is an undulating gimp yarn, often produced by binding an irregular yarn, for example a stripe, slub or knop yarn, in the direction opposite to the initial stage, creating graduated half-circular loops along the compound yarn. It produces an uneven but relatively controllable texture. Because it can be produced using one of several different irregular yarns to create the effect, and because the basic morphology is very similar to that of a gimp yarn.
The bouclé yarn is very similar in construction to the gimp yarn. It requires a minimum of three component yarns: core, effect, and binder; and it is produced in two stages. The yarn construction is illustrated in Figure 7. The main difference between a boucle yarn and a gimp yarn is that the wavy projections on the boucle yarn surface are further away from the yarn body, a result of greater overfeeding of the effect yarn during the first twisting stage. On the account of greater overfeed, the effect spirals very loosely around the core following the first twisting stage. The wavy projections can be more easily distorted during the second twisting stage, leading to a more variable yarn appearance.
Loop yarns are characterized by circular projections formed by the effect yarn. They are typically formed by at least four component yarns: two cores, the effect, and the binder. Two cores are required to form a stable triangular space in which the overfed effect yarn can accumulate to produce the loops during the first twisting stage, shown in Figure 8.
The first stage yarn must be further processed by a reverse binding process to fix the loops onto the core yarns because in the first twisting stage, the core and effect yarns simply twist around each other and the loops are not trapped by the core yarns. The effect yarn is usually overfed by 200% or more relative to the core yarns. To produce uniform and stable loops, it is important that the effect yarn is made from elastic and pliable fibers such as mohair, and is not twist lively. Rovings of long staple fibers may be used as effects to produce loose fiber loops.
Although the loop size is obviously dependent on the effect overfeed ratio, it can also be controlled by the spacing of the two core yarns, the twist level used during the first twisting stage, and the yarn tension. Controlling the twist level is the easiest way to alter the loop size, as it does not require the change of any of the spinning machine parts. The reverse binding process also affords the opportunity to readjust the final yarn twist so that the yarn is not overly hard.
A stripe yarn contains alternating elongated knops, revealing a separate core. The sections of yarn between the knops take on the appearance of a multi-threaded marl yarn.
A cover yarn is one in which a yarn at the core is completely covered by fiber or yarn wrapped around it. It is familiar to embroiderers, because many metallic embroidery threads take the form of a core thread with a metallic thread, film or fl at ribbon wrapped around it, but the method is most commonly used to cover elastomeric yarns, which would otherwise be extremely uncomfortable to wear. The extremely eccentric ‘bubblegum yarn’, which consists of a core of filaments surrounded by a bubbled froth of soft resin, could also be described as a cover yarn.
Snarl yarns are made in exactly the same way as loop yarns, except that the effect yarn is twist lively instead of stable. Due to the twist liveliness, the loops formed by the effect yarn collapse under the influence of the untwisting stress in the yarn and form kinks. An example is shown in Figure 9. To enhance the formation of the snarls, the effect yarn overfeed is usually higher than that used for loop yarns.
A knop yarn contains sections, with only the effect yarn being visible as shown in Figure 10. These sections on knop are formed when the core yarn is stopped momentarily while the effect yarn feeding continues. The excess effect yarn wraps around the core yarn at the same spot, forming these bunches. Between the knop sections, the yarn resembles a normal plied yarn. For all the other yarns described previously, the effect yarn overfeed, when used, is constant during production; for knop yarns, the overfeed is controlled. The feeding device for the core yarn must therefore be able to change speed during production. The formation of the knop can be controlled by a device called knopping bar or a control bar. The extent of the knop can be spread by the movement of the knopping bar, producing elongated knops or stripes. The core yarn and the effect yarn may be stopped at alternating intervals, leading to a yarn showing alternating sections of one of the component yarns. This type of yarn is also called cloud yarns.
Cloud or grandrelle yarn:
A cloud or grandrelle yarn is made using the apparatus used to create knop yarns. The two threads of different colors used to create the yarn are manipulated in such a manner that each thread alternately forms the base and cover to ‘cloud’ the opposing thread. It is made by alternate fast and slow deliveries from two pairs of rollers. Because the yarns alternate in forming the base yarn, no dedicated core yarn is required.
Eyelash or feather yarn:
The eyelash or feather yarn has an asymmetric structure consisting of a looped spine or core, with a fringe of effect yarn to one side of it. It is created using enhancements to the chainette process and is popular in fashion knitwear, where it creates a shaggy pile effect. In Figure 12 the eyelash yarn has been shown with both cut and uncut fringe loops.
A chenille yarn consists of a cut pile that is trapped by the core yarns. The basic structure of a chenille yarn is shown in Figure 13. The production of chenille yarns can be accomplished on a dedicated chenille machine, which will be described later in this chapter. These yarns can also be produced by other methods such as weaving or flocking.
Further twisting may be necessary to enhance the binding of the piles formed from the cut weft yarns. It should be obvious that chenille yarns made in this way are expensive. A faster and more economical process for making chenille yarns is flocking. To ensure the fibers form standing piles on the core strand, flocking is usually carried out in an electrical field. The loose fibers are charged with an opposite electrostatic charge to the core strand. Chenille yarns produced by flocking tend to have lower abrasion resistance, as the fiber pile is only stuck to the core by the adhesive, whereas the pile in other chenille yarns is trapped by intertwining yarns.
The most recent addition to the armoury of the chenille spinner is the development of an intermittent chenille yarn, often referred to as a ‘pompom’ or ‘marshmallow’ yarn. This yarn alternates sections of chenille yarn with a simple cabled yarn, and is targeted at the hand knitting market. It results from refinements in the technology and process control, and has created considerable interest in its target market.
A diamond yarn is made by folding a thick single yarn or roving with a fine yarn or filament of contrasting color using an S-twist, and cabling it with a similar fine yarn using a Z-twist. A true diamond yarn will show some compression effect upon the thick yarn from the thin ones, an effect which in the interests of clarity has been omitted from Figure 15 .
This is a staple fiber yarn which, by virtue of the method used in its manufacture, consists of a core of parallel fibers bound together by wrapper fibers (Figure 16). The yarns produced under the hollow spindle method are also frequently described as fasciated, since the binder is applied to an essentially twistless core of parallel fibers.
Clothes of metallic threads, of gold or silver, are known to have been made thousands of years ago. Modern metallic yarns are, however, usually only made from laminated plastic films. The films are first coated on both sides with metallic paint of suitable color, a further transparent coating is applied on top to enhance the wear resistance. The films are cut into thin strips to be used as yarns. It is unusual to use these slit film yarns directly in fabrics because of poor abrasion and strength properties. They are often used as a component in a compound yarn. Figure 17 shows an example of a metallic yarn.
The ‘button’ is an intermittent effect, created by a sudden pause in the progress of the core yarns, which allows a build-up of the effect material, usually in this case a sliver or roving (Figure 18). While in yarn form it can offer a truly dramatic effect, it is less than straightforward to process into fabric, and in practice it is usually found in its more discreet manifestations. The exception to this is of course in hand knitting yarns, since it can be expected that a hand knitter will be able to devote the time and care required to achieve a successful result.
Tape yarns may be made by a variety of methods, and take the form of flat ribbons or tapes. In recent years, these materials have become better known, especially in fashion knitwear. They may take the form of genuine ribbons or tapes, woven on narrow-fabric looms, or they may have a knitted or braided structure.
Uses of Fancy Yarns:
As the primary aim of using fancy yarn is to enhance the aesthetic appearance of fabrics, there is a continued effort by producers to come up with new yarns that differentiate themselves from competitors. Fancy yarns have wide-ranging application in apparel at all levels of the market. Upholstery and home furnishings have offered a relatively new field to spinners of fancy yarns over the past 20 years.
However, one main drawback of using fancy yarns lies in the increased costs of yarn, fabric, and garment manufacture. The production speeds for fancy yarns are generally slower than for plain commodity yarns because of the inherent unevenness of fancy yarn. In addition, most fancy yarns require multiple components and several twisting stages, so the cost of fancy yarn production is typically several times that of commodity yarns.
Fancy yarns are also far more sensitive to fashion trends, so it is unwise to produce large quantities without order confirmations. Any redundant stock will be highly costly to the yarn producer. In fabric production, the uneven nature of fancy yarns will demand more careful handling and slower production speeds, leading to increased fabric costs. The interaction with the fabric structure also means that the final appearance of the fancy effects can be unpredictable, so in most cases, samples must be produced prior to normal production.
With some exceptions, the use of fancy yarns will lead to lower fabric performance in terms of strength, wear resistance, and aftercare. Careful consideration must therefore be given to the performance requirement of the end use and to the quantities of fancy in the fabric when fancy yarns are to be used. Given the higher costs and lower performances, the main use of fancy yarn is usually more for high value and high margin applications.
Fancy yarns are used in weaving of suiting, shirting, dress material, upholstery, furnishing fabric and woolen tweeds.
Fancy yarns are also used for decorative textiles like:
- Ladies and children outerwear
- Decor materials and textile fabrics in the corporate sector, as for example in the trim of a car or textile furnishing of a hotel lobby are becoming more and more important.
- Textile and Clothing Design Technology Edited by Tom Cassidy and Parikshit Goswami
Specialist Yarn and Fabric Structures: Developments and Applications Edited by R. H. Gong
Fancy Yarns: Their Manufacture and Application By R H Gong and R M Wright
Technical Textile Yarns: Industrial and Medical Applications Edited by R. Alagirusamy and A. Das
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Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.