A fancy yarn is made with a distinctive irregular profile or a construction that differs from the basic single and folded yarns, the objective is to enhance the aesthetics of the end product.

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. Figure1 shows some of the fancy effect yarns. This is not comprehensive. Various names are used to describe the different yarn effect, these can be classified in to Eight basic profiles.

Fig.1 Twist effect fancy yarns

The basic profiles of the fancy yarns are Spiral, Gimp, Slub, Knob, Loop, Cover, Chenille and Snarl yarns. The fancy effect can be optioned with two ways .1). By twisting and or doubling technique and 2.) With spun effect by means of fibres. The effects may be randomized and regular effects.

Basic Principle

A ground (core) component, an effect component and a binder in a fancy yarn are shown in the figure2. To obtain structural effect, longer length of effect component, relative to ground component must be present to form the required effect. Twisting of the effect component on to the ground component will produce aesthetic effect.

Fig.2 Basic components of Fancy yarn

G roller can be made to stop for a very short period at irregular intervals, while the E rollers are still feeding the effect yarn in to the twisting zone. To assist the occurrence of the effect yarn on the ground yarn, a metal bar (space bar) positioned to separate the yarns.

Fig.4.Threading arrangement for Fancy yarns

The second approach in forming the knob yarn is to have both yarns constantly running over the small over feed of the effect component. The spacer bar is made to oscillate up and down continuously to alter the distance of the travel go the effect component. Fibre fineness, fibre length, count and twist direction of the component yarns are the deciding factors on the fancy yarns.

Types of Fancy yarns
Spiral yarn

Plying technique used here. Typically, two single yarns of different thickness and twist level are plied together with slight over feed of course yarn. It shown in the figure.5

Fig 5. Structure of Spiral yarn structure

Gimp yarn

Both the plying technique and the hollow spindle process could be used to make this yarn. using hollow spindle process two ground yarns on which the drafted ribbon can be made to buckle in to the form of wavy shape, a typical shown in the figure 6.

Fig 6. Structure of Gimp yarn

Loop yarn

The threading arrangement of the component yarns to form loops is similar to that of gimp shown in the figure 7.The considerations to for the loop yarns are the type of fibers, level of twist applied and the percentage of over feed employed at the profile stage.

Fig 7.Structure of Loop yarns

Snarl yarns

This also produced by plying process. The profile component is a highly twisted yarns shown in the figure 8.

Fig 8.Structure of snarl yarn

Knob yarns

The knob yarns can be constructed by the joining or the plying system by using the over feed of 150-200%, but the profile is visually not as well as defined in the spinning process because a drafted ribbon is used as the profile component. The Knob yarn shown in the figure 9.

Fig 9. Structure of Knob yarns

Cover yarn

The cover yarns are made by plying process the threading arrangement is identical to the knob yarn. Two pair of rollers controlling the yarns are made to start stop as required. However instead of stopping, each pair of rollers will in turn slow to a speed ,that allows the other yarn to wrap around that fed by slowed rollers. The level of twist required is high in order of 1600t/m.A typical structure of the Cover yarn shown in the Figure 10.

Fig 10.Structure of Cover effect yarn

Slub yarn

The production of the ground and injected Slub yarns was considered this case the roving is replaced as a profile component, roving periodically stop and start accordingly to the required Slub length and spacing. The Slub thickness is determined by the roving count.

Fig 11.Structure of Slub yarn

Chenille yarn

This was made originally by the Leno weaving Two weft yarns are placed between each crossing of the weft yarns. After weaving the weft ,length extended between the warp yarns is cut to produce the pile effect .this traditional Chenille yarn shown in the figure12.

Fig 12. Structure of Traditional Chenille yarn

A mock chenille yarn effect can be obtained with either hollow spindle or by plying process for the production of small loops and these are wrapped or plied together to give a plied effect.

Summary

Production of Fancy yarns is a combination of art and science. There are lot of scope for the innovators to develop new products in Textiles using Fancy yarns. Apart from the Domestic market, Export of fancy yarns, Fabrics and Garments may provide great Opportunities in future.

References

1.Production of fancy yarns and their uses, KR.. Salhotra-IIT Delhi
2.Fundamentals of Spun yarn Technology-A.Lawrence-CRC Press, London2002.
3.Testore and Minero, Study on fundamental parameters of some Fancy yarns, Journal of Textile Institute-1988

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