yarn classification

1. YARN CLASSIFICATION

2. • Yarn is “a generic term for an assemblage of fibres that is laid or
twisted together or a continuous strand of textile fibers, filaments, or
material in a form suitable for knitting, weaving, or otherwise
intertwining to form a textile fabric.
• Yarns play an important role in the fabric manufacturing process
since a majority of the textile materials are constructed with yarns.
• Yarns are also used for products such as sewing and embroidery
thread, string, and rope.
• Yarns are produced in various sizes and textures, and also vary in
other characteristics.
• Yarns are classified by number of parts, twist, size, length and
special uses.

3. I. CLASSIFICATION OF YARN ON THE BASIS OF LENGTH
• According to fibre length yarns are broadly divide into: –
 Spun yarns (made from short, staple fibres)
 Filament yarns (made from continuous filament fibres).
• Spun yarns are composed of short staple fibres, or
• long filament fibres that have been cut into short staple fibres.
• Spun yarns may contain fibres of the same type or a blend of different
fibres.
• The spinning method used to manufacture the yarn affects properties
such as uniformity and strength.

4. • Filament yarns are extruded yarns that are made of natural extruded
fibres or manufactured fibres extruded through the spinneret.
• These yarns fibres can be broadly divided into:
• 1. Monofilament yarn is made from a single, relatively thicker
filament fibre. Transparent sewing thread, metallic yarns, bare
elastic, and fishing lines are examples of monofilament yarns. Silk is
too fine to be used as a monofilament yarn.
• 2. Multifilament yarn is made from multiple filament fibres.
Continuous filament fibre length requires little or no twisting to hold
the multifilament yarn together. Some filament yarns are produced
by slitting or splitting yarns sheet or film of metallic-coated or
polymer yarns. Some examples are: Metallic-coated yarn is made by
slitting a metallic foil laminated between plastic films.

5. CLASSIFICATION ON THE BASIS OF NUMBER OF PARTS
• Yarns can be classified as simple, novelty and textured yarns on the
basis of number of parts.

6. • i) Simple Yarns:
• Yarns that are even in size, have an equal number of turns or twist per
inch throughout their length and are relatively smooth and uniform are
called simple yarns. In general simple yarns tend to produce smooth flat
fabrics. Simple yarns are classified as single, ply and cord. They may
be made of stable fibers or filament fibers.
• A single yarn is the product of the first twisting operation that is
performed by the spinning machine, in which fibres are twisted together
to make a yarn.
• A ply yarn is made by a second twisting operation, which combines two
or more single yarns

7. • Each part of the yarn is called a ply e.g.2 ply yarn, 3 ply yarn etc.
• The twist is inserted by a machine called a twister.
• Plying tends to increase the diameter, strength and quality of the
yarn.
• A cord is made by a third twisting operation which twists ply yarns
together.
• A rope yarns are produced by twisting two or more cord yarns.

8. ii) Novelty yarns or specialty or Complex yarns:
• Novelty yarns, typically made of two or more stands, are produced to provide
decorative surface effects.
• They differ from simple yarns in that their structure is characterized by
irregularities in size, twist and effect
• A typical novelty yarn has three basic parts:
1. The ground or foundation: The ground or foundation (base/core) strand provides
the structure and strength.
2. The fancy or effect: The effect strand creates decorative detail such as knots and
loops.
3. The binder: The binder is used to tie the effect yarn to the base yarn if binding is
necessary
Figure 4: Typical Structure of Novelty Yarn

9. • CHARACTERISTICS OF NOVELTY YARNS
• Novelty yarns are usually plied yarns, but they are often weak and
sensitive to abrasion damage.
• These yarns are generally used in one direction only, ie, in the filling
direction because it is more economical and wastage is lesser.
• Also, filling yarns are less susceptible to damage due to strain and are
easier to vary for design purposes.
• These yarns improve the aesthetic appeal of a fabric at a lower cost.
• The durability of a novelty yarn depends on the size of the ply effect,
the fibre content and firmness of the fabric structure.
• Usually, the smaller the novelty yarn, the more durable is the fabric.
• The quality and cost of novelty yarns are related to the quality of the
fibres and plies from which, the yarn is made and also the regularity of
yarn structure.
• Novelty bulky yarns add crease resistance to the fabric.

10. • CLASSIFICATION OF NOVELTY YARNS
• Novelty yarns are classified according to the single or ply structure:
• Single yarns are Tweed and Slub Yarns.
• Ply Yarns are Ratine, Spiral, Knot, Snarl and Boucle.
• Apart from these, there are many other novelty yarns like Chenille,
Flake, metallic and textured yarns.

15. • The terminology as well as the classification for novelty
yarns varies considerably.
• Some of the commonly used novelty yarn categories are
included in this section.
• Novelty yarns are made on twisters with special
attachment for giving different tensions and rate of
delivery to the different plies (parts) of yarns and thus
allow loose, curled, twisted or looped areas in the yarns.
• There are different types of novelty yarn like slub, flock,
ratine, boucle, core spun nap etc.

16. • Textured yarns are made of fully drawn filament fibres with a
changed surface, shape and texture developed by using the new
spinning techniques.
• Nylon and polyester are two main fibres that are textured.
• Textured yarns provide many variations in fabric properties.
• There are two main types of textured yarns:
• Stretch yarns and Bulk yarns

17. • Stretch yarn can be made by using any of the following methods:
a. By using special heat setting treatment to thermoplastic filament fibres
such as nylon and polyester.
b. From elastomeric fibres.
c. From bi-component fibres.
d. From bi-constituent fibres.
e. From chemically treated natural fibres.
• Bulk Yarns are softer and much pliable then tightly constructed twisted
yarns. Bulk yarns are also have a better cover. They create less
transparent fabrics and are of two types:
• Figure 6: Bulk Yarn
• High bulk yarns Loop-bulk or airjet yarns

18. • Characteristics of textured yarns
• Texturing gives slippery filament the aesthetic properties of spun
yarn by altering the surface characteristics and creating space
between the fibers.
• This gives the fabric more breathability and more permeability to
moisture and fabric is more absorbent, more comfortable, has less
static build up. Bulk, cover, and elasticity or stretch is increased.
Texturing also decreases pilling and shedding that occurs with
manmade spun yarns.
• Textured yarns are commonly classified as follows:
• Stretch textured yarn
• Set-modified stretch – textured yarn
• Bulked textured yarn

19. • 1. Stretch textured yarns:
• Stretch type textured yarns are characterized by high elongation 300
to 500 percent, rapid recovery from elongation & moderate bulk.
The major uses for stretch yarns are in stretch fabrics.
• Stretch yarns are made primarily of nylon fiber & have been used
extremely in knits.
• There are two kinds of stretch yarns:
• (1) Coil type stretch yarns made by the false twist method & three
stage twist process,
• (2) curl type stretch yarns made by the edge crimping method.

20. • Three stage twist process It includes the steps of :
• twisting the yarn
• setting the twisted yarn by the application of heat
• Untwisting the yarn.
• False twist process: A variation of three stage twist process is known
as false twist process, which is same as the three stage process
except that it is a continuous operation that adds second heater to
stabilize the untwisted yarn to produce modified stretch yarn.
• Edge crimp curl type yarns: Curl type stretch yarns are made by
drawing heated filaments over a knife like edge, which flattens the
filaments on one side & causes the yarn to curl, with an effect like that
obtained by pulling a ribbon over scissors to curl it. The filament cross
section changes from round to flattened on one side.
•
•

21. • Modified stretch yarns:
• Stretch yarns that have been subjected to heat treatment
to stabilize the yarns are known as modified stretch
yarns. These yarns possess some degree of stretch but
are more stable than stretch yarns that have not been
heat set. Modified stretch yarns are produced on the
same machinery as stretch yarns but add the required
heat treatment as the last step of manufacture.

22. • 2. Bulked yarns:
• Bulked yarns are used in those applications in which bulk is more
important than stretch. Bulked yarns also have moderate stretch but
not enough to be classified as stretch yarns. Products in which
bulked yarns are most often found include sweaters, warm hosiery,
carpets, wool like knits & upholstery. Bulk texturing is done by:
• Gear crimping - saw tooth crimp
• Stuffer box process – saw tooth crimp
• Air jet process
• Knit - deknit process

27. • APPLICATION OF TEXTURED YARNS-
• Stockings and tights (panty hose), swimwear, sportswear,
outerwear, underwear, carpets, sewing and overedge stitching
threads for extensible fabrics.

28. III. CLASSIFICATION ON THE BASIS OF YARN TWIST
• Twist is defined as the spiral arrangement of the fibers around the axis of
the yarn.
• Twist binds the fibers together and gives the yarn strength.
• The number of twists is referred to as turns per inch.
• The direction of twist is described as S twist and Z twist.
• A yarn has S twist if, when held in vertical position, the spirals conform to
the direction of slope of the central portion of the letter “S”.
• It is called Z twist if the direction of spirals conforms to the slope of the
central portion of the letter “Z”.
• Z twist is the standard twist used for weaving yarns.

30. CLASSIFICATION ON THE BASIS OF CARDING and COMBINING

31. • Same count of combed and carded yarns has many different characteristics
which is totally influence in the quality of fabric.
• The finished knit fabrics made by combed yarn and carded yarn have no
important change because of color fastness to light and color fastness to
wash.
• In case of color fastness to rubbing, a little effect is found on finished knit
fabric made by a same count combed yarn and carded yarn. In some other
cases, combed yarn shows better result than carded yarn.

32. v. CLASSIFICATION ON THE BASIS OF COMBING OF YARN
• On the basis of combing the yarn can be classified of worsted and woolen yarn.
• Woollen spun yarns are carded to separate the fibres into a web, or a
roving/roles for hand spinners. So the fibres are spread out evenly in order to
make a yarn of even thickness along its length, but they remain scattered in all
directions in the yarn.
• This means that the yarn is:
• Light and full of air
• Fluffy or even hairy
• Able to insulate well in use and making a light and thick fabric when knitted or
blankets, scarves, shawls and tweed when woven and for carpets
• Breakable by hand, so only good for a weft if used in weaving unless specifically
made for weaving with added twist
• Likely to have a few remaining seeds or pieces of vegetation that did not fall out
in processing
• Made of the whole fleece, including coarser and finer fibres and hairs (kemp and
modulated fibre and guard hairs)

33. • Worsted spun yarns are part carded (scribbled) before coiling into a can
and then passing through gills (called pin drafting in the US), which align
the fibres, and combs, which remove short hairs, coarse hairs and
vegetable matter. The result is tops, which are then re-gilled, auto-
levelled and split for worsted spinning. This means that the yarn is:
• Denser and heavier than woollen spun yarns, with little air, so will make a
more drapey fabric
• Smooth and soft-feeling, even if made with quite coarse fibre, as the
most coarse will have been removed
• Strong and able to be used as a warp in weaving without additional twist,
used in suiting and finer fabrics and/or hard-wearing fabrics
• Less economic to make as more fibre is removed in processing
• Refined and luxurious
• At risk of pilling or shedding if made with short or smooth fibres, which
are held in better in a woollen spun yarn