Types of Fancy yarn used in Textiles fiber (effect/nepp):-

Textiles yarn are the basic elements of fabric. For fabric design and production, yarn are mainly considered in terms of their color structure and materials, properties. Colours and the structure of yarn contribute to the fabric texture, covering power , luster and thickness. The "Fancy yarn" may be taken to cover all fancy doubled yarn "cover yarn" and fiber effect , color effects and effect based on metallic components are also available. Fancy yarn that are designed mainly for their aesthetic appearance rather than performance. Many fancy yarn 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 a very important here because all yarns made from staple fibes are inherently variable due to the imperfection of the yarn Spinning system and the non uniformity of fiber material.

Image of Different types of fancy yarns.

In the production of normal regular yarn, effort are made to minimize these variations so that the eventual fabric uniformity and performance properties. Such as strength and abrasion, resistance are maximize. In the fancy yarn , however the variation are introduced by designed to enhance the aesthetic appearance. These yarns provide the fabric designer greater scope in achieving a more attractive and exclusive product, but also pose greate challange ad they usually suffer from poorer performance and higher costs. Fancy yarn structure are manifested in terms of irregularities of curvatures of the central yarn axis and changes in the diameter of cross sections in the yarn. The fancy yarn gives a fancy touch to the fabrics to a broad range of end use . Significant demand for the fancy yarn is the ladies and children outer wear.
The basic structure of the fancy doubled consist of "core threads " and ’effect material 'and " binder" which as the name suggests, ensures that the entire structure hold together.

Different types of fancy yarns:-

It would be a futile attempt to try to describe all the verieties of fancy yarns as these are designed to differ by defination. From the point of how the variation is introduced in the yarn, fancy yarn effects may be broadly divided into to categories;
1. Fiber effect and
2. Yarn effects.
Fiber effects are introduced prior to the formation of yarn; yarn effects are introduced by combining two or more yarn after the individual yarns have already been made . The categories can obviously be combined to make more complex effect.

1) Fiber effect:-

Fiber effects fancy yarn are created during the spinning process prior to the formation of the final yarn. These yarns are characterized by varying size of fiber lumps along the yarn length.
Depending on the size of these fiber lumps, these fiber effects are often further divided into their subcategories nepp, slub, and flake .

Nepp yarn:-

Nepp yarn or nupp yarn , has a compact yarn structure with specks of fiber cluster distributed along the base yarn structure. Figure 1 shows an example. These yarn are most effective when the effective , when the effect fiber, whereas more subtle effect can be created when the effect fiber and the base yarn have similar colours. The distribution of the effects should generally be random to avoid the moire effect as shown in
Fig 1 .

Fig. 1 ,Nepp yarn.

The production of nepp yarns are usually achieved during the preparation of fibers. The most widely used method is mixing prepared fibers ball 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 bale will be opened upto smaller but more frequent , conversely, if the card setting are more open, their fiber balls will have a larger and looser, but less frequent effects. Due to the more vigorous action of cotton card, other wise the fiber ball will mostly be opened up and the effect 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 of during fabric production and subsequent end use.

Slub yarn:-

Slub yarns are more pronounced effects compared with nepp yarns Fig. 2 shows an example of slub yarn . There are more commonly produced during processes after carding but prior to the formation of final yarn . These effects can be formed by introducing additional fiber into the fiber flow. The introduction of additional fiber can be carried out during drafting in the spinning process or during condensation in the woolen process.

Fig . 2 slub yarn image.

Unevenness can be introduced by varying the drafting roller speed in the 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 exploits the fact that fibers of dramatically different length tend to cluster during roller drafting, so mixing and during drafting, the shorter fiber tend to cluster together to form slub.

Flake yarn:-

Flake yarns contain larger and usually looser fiber clusters then slub yarns . These yarns are sometimes also called flamme yarns. Fig 3 shown an example of flake yarn . In many ways , flake yarns may be considered as more pronounced slub yarns, but these effects can be created by controlled introduction or injection of additional fibers into the fibers into the fiber stream before Spinning.

Image of Flake yarn Fig. 3

2) Yarn effects:-

Yarn effects are also sometimes called ply 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 contains atleast two basic components yarn; 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 the ground yarn. In reality, the veriety of fancy yarn 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 ro make thin strands and use them as yarn. These types of fancy yarns are excluded here.

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