Different Types of Fiber Effects and Yarn Effects of Fancy Yarn

What is Fancy Yarn?
Fancy yarn is one type of yarn that has special characteristics or decorative elements added to its structure. It is also known as novelty yarn. Fancy yarn can be made during the spinning process, and it can provide a wide variety of textures and colors to the yarn. The basic components of fancy yarn are the base (or core), the ‘effect’ yarn, and, sometimes, a binder to hold everything together. Fancy yarn can be used to add texture, visual interest, or decorative effects to various types of garments, accessories, or home decor items.

Adding a variety of colors to the textured yarns lend a mottled or marbleized effect to the fabric, whereas combining matt and lustre effects with the fibers produces fabrics such as Lurex. However, the durability of these yarns is not as good as the uniform-spun yarns.

Types of Fancy Yarn Effects:
Fancy yarns may be categorized according to their basic morphology. Fancy yarn effects can create textured, shimmering, feathered, looped, patterned, and other unique effects in fabrics, adding visual interest and enhancing the overall aesthetic. Fancy yarn effects may be broadly divided into two categories:

1. Fiber effect and
2. 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.

A. 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.

1. Nepp yarns:
Nepp yarn, or nupp yarn, has a compact yarn structure with specks of fiber clusters distributed along the base yarn structure. 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. It is, however, possible to deliberately create periodical effects if the moire pattern is a designed outcome.

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.

2. Slub yarn:
Slub yarns are more pronounced effects compared with nepp yarns. This is a yarn in which slubs are deliberately created to make the desired effect of discontinuity. These are either single or folded yarns that have thicker areas where the fibers are usually more loosely spun at regular or irregular intervals along the length.  Slubs are thick places in the yarn that may take the form of a very gradual change, with only a slight thickening of the yarn at its thickest point. Alternatively, a slub may be three or four times the thickness of the base yarn and the increase in thickness may be achieved within a short length of yarn. The yarn pictures in Figure 2 should give a clear impression of the structure of the yarn itself. Slub yarns are more commonly produced during processes after carding but prior to the formation of the final yarn. The fabrics may look like linen.

3. Flake yarns:
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.

B. 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.

1. Marl yarn:
Marl yarns are probably the most simple plied yarn structures. This yarn is made by twisting two different-colored yarns in a doubling process. It differs in texture from normal double yarn. The yarn structure shown in Figure 4 clearly shows the alternation of colors, which is the primary effect of marl yarn, as well as demonstrating the plain structure, which is that of an ordinary folded yarn. These yarns are used to make discreet pinstripes in men’s suiting or to produce a subtly and irregularly patterned knitted fabric with a relatively simple fabric construction. They may also be used to provide a Lurex or other metallic yarn with strong support, while at the same time creating a more subtle effect. 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.

2. 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. In most cases, two yarns of contrasting linear densities are used. Spiral yarns can be produced with one component yarn being fed faster than the other.

3. Gimp 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.

4. Eccentric yarn:
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, no diagram of the structure has been included, since at its most straightforward it would be a repeat .

4. Boucle yarn:
This type of yarn is characterized by tight loops projecting from the body of the yarn at fairly regular intervals, as shown in Figure 7. Some of these yarns are made by air-jet texturing but most are of three-ply construction. The boucle 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 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.

5. Diamond yarn:
A diamond yarn is produced by folding a coarse single yarn or roving with a fine yarn or filament of contrasting color using S-twist. This is cabled with a similar fine yarn using Z-twist. Multifold ‘cabled’ yarns may be made by extending and varying this technique to produce a wide range of effects. A true diamond yarn would show some compression effect upon the thick yarn from the thin ones, but in the interests of clarity this is not shown in Figure 8. Diamond yarn is very useful to designers in the creation of subtle effects of color and texture, particularly in relatively simple fabric structures.

6. Loop yarn:
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 9.

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. The size of the loops may be influenced by the level of overfeed, the groove space on the drafting rollers, the spinning tension or the twist level of the effect yarn. Loop yarns may also be made with slivers in place of yarns for effect.

7. Snarl yarn:
Snarl yarns are made in exactly the same way as loop yarns, except that the effect yarn is twist lively instead of stable. A snarl yarn displays ‘snarls’ or ‘twists’ projecting from the core. 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 10. To enhance the formation of the snarls, the effect yarn overfeed is usually higher than that used for loop yarns. The required size and frequency of the snarls may be obtained by careful control of the details of overfeed and spinning tension, and by the level of twist in the effect yarn.

8. Knop yarn:
A knop yarn contains prominent bunches of one or more of its component threads, which are arranged at regular or irregular intervals along its length (Figure 11). A knop yarn contains sections, with only the effect yarn being visible. 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.

9. Chenille yarn:
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. These yarns can also be produced by other methods such as weaving or flocking.

A faster and more economical process for making chenille yarns is flocking. In this process, a continuous core strand, usually of filaments, is coated with adhesive and flocked with loose fibers. 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.

10. Chainette yarn:
Chainette yarn, shown in Figure 14, is produced in a miniature circular weft knitting process, often using a filament yarn and a ring of between 6 and 20 needles. The process has been used on a small scale for many years and is now used extensively in fashion knitwear.

11. Metallic yarn:
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.

12. Tape yarn:
Tape yarns may be produced using various processes including braiding, warp knitting and weft knitting. In recent years, these materials have become better known, especially in fashion knitwear. It is also possible to use narrow woven ribbons, narrow tapes of nonwoven material, or slit film in the same way.

13. Ribbon yarn:
These yarns are not produced by spinning and consist of finely knitted tubes, pressed flat to resemble ribbon or tape. The ribbons are usually soft, shiny and silky.

14. Composite yarns:
Also known as compound yarns, these consist of at least two threads. One forms the core of the composite yarn, and the other strand forms the sheath component. One thread is a staple-fiber yarn and other a filament yarn. Compound yarns are even in diameter, smooth and available in the same count range as spun and filament yarns.

15. Covered yarns:
Covered yarns have a core that is completely covered by fiber or another yarn. Figure 15 shows different types of covered yarns. The core might be an elastomeric yarn, such as rubber or Spandex, or other yarns, such as polyester or nylon. Covered yarns may have either a single or double covering. The second covering is usually twisted in the opposite direction to the first. Single-covered yarns have a single yarn wrapped around them. They are lighter, more resilient and more economical than double-covered yarns and can be used in satin, batiste, broadcloth and suiting as well as for lightweight foundation garments. Most ordinary elastic yarns are double-covered to give them balance and better coverage. Fabrics made with these yarns are heavier.

16. Fasciated yarn:
This is a staple-fiber yarn that consists of a core of parallel fibers bound together by wrapper fibers. Yarns made by the air jet spinning method are structured in this way. Yarns produced by the hollowspindle method are also frequently described as fasciated, as the binder is applied to an essentially twistless core of parallel fibers. The fasciated yarn shown in Figure 16 is produced using the hollowspindle process. It is possible to see fibers that have escaped the dark binding thread and contrast with one of the two slivers used as feedstock in making the yarn.

17. Stripe yarn:
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.

Application / Uses of Fancy Yarns:
Fancy yarns offer a wide range of applications across various industries and creative endeavors. They are point our below:

1. Fashion industry: Garments, accessories, textiles.
2. Home decor: Throws, cushions, curtains, rugs.
3. Crafts and hobbies: Knitting, crocheting, weaving, handmade items.
4. Upholstery: Furniture fabrics.
5. Art and installations: Artwork, mixed media projects, three-dimensional forms.
6. Costume design: Theater, film, performing arts.
7. Textile accessories: Belts, bags, shoes.
8. Novelty items: Toys, stuffed animals, decorative ornaments.
9. Interior design: Wall hangings, tapestries, room dividers.
10. Collaborative projects: Artistic collaborations, innovative creations.
11. Weaving: Tapestry weaving, wall hangings, rugs.
12. Embroidery: Embellishments, decorative stitching.
13. Mixed media art: Incorporating yarn into paintings, sculptures, collages.
14. Jewelry: Yarn-wrapped accessories, tassels, statement pieces.
15. Stationery: Yarn embellishments on greeting cards, gift wrapping.
16. Cosplay and fantasy costumes: Elaborate character costumes, props.
17. Fiber art: Sculptures, installations, fiber-based creations.
18. Education: Textile art classes, workshops, demonstrations.
19. Advertising and visual merchandising: Eye-catching displays, visual impact.
20. Pet accessories: Pet beds, toys, collars with yarn elements.

References:

1. Textile and Clothing Design Technology Edited by Tom Cassidy and Parikshit Goswami
2. Textiles and Fashion: Materials, Design and Technology Edited by Rose Sinclair
3. Fibres to Fabrics by Bev Ashford
4. Specialist Yarn and Fabric Structures: Developments and Applications Edited by R. H. Gong