2. Yarn | Types of yarn
Yarn
Generally yarn is a continuous strands which
is made up of filament, fibres or materials
where the materials are suitable for knitting,
weaving, otherwise forming a textile fabric.
Yarn is an assembly of
fibres that are twisted together to form a
continuous strand. Yarns may be made from
either staple fibres or filament fibres. Staple
fibres are twisted into yarns; filament fibres
need little or no twist to hold them together
into yarns. The type & length of fibre, the
type, ply & size of yarns & the amount of
twist given to yarns determine many of the
characteristics of fabrics made from the yarns.
3. All fabrics except plastics & non-wovens
depend upon the use of yarns. For example,
fabrics constructed of spun yarns are less
smooth than fabrics constructed of filament
yarns. They also have a lower lusture cord or
rib fabrics contain ply or larger yarns in the
rib direction.
Types of Yarn
Yarn may be classified into several types:
1. Mainly
a) Staple yarn.
b) Single.
c) Simple.
b) Filament yarn.
d) Piled or folded.
e) Complex.
2. On the Basis of processing
a) Combed yarn.
b) Carded yarn.
4. 3. On the Basis of spinning machine used
a) Ring yarn.
b) Rotor yarn.
c) Air-jet yarn.
4. On the direction of twist
a) Z twisted yarn.
b) S twisted yarn.
Types of yarns on the basis of Structure
Another classification of yarn can be obtained
on the basis of structure and this classification
is easier way to understand and define many
types of textile yarns. Here the classification is
given below :-
1. Single yarn.
(i) Continuous filament.
(a) Mono-filament.
(b) Multi-filament.
(ii) Staple yarn or spun yarn.
(a) Homogenous.
5. (b) Blended.
(iii) Modified continuous filament.
2. Multi folded or Plied yarn.
3. Cabled yarn.
4. Gimped yarn.
5. Complex yarn or Core-spun yarn.
6. Fancy yarn or Novelty yarn.
7. Strength yarn.
8. High bulked yarn or texturized yarn.
9. Metallized yarn.
Explanation of different types of yarn
1. Single yarn
6. Single yarn is the simplest continuous strand of
textile mtl composed of one of the following :
-
(i) Continuous filament
Filament consists of very long, thin cylinder
type fibre twisted together. Continuous
filament yarns are the simplest in the structure
but can be subjected to many modifying
process for changing their texture,
extensibility, bulk and other properties. In the
manufacture of man made filaments, a solution
is forced through very fine holes of spinneret,
at which point the solution solidifies by
coagulation, evaporation or cooling.
Continuous filament yarns in fabric form
usually have excellent strength & uniformity.
This yarn can be made much finer in linear
density and diameter than staple yarns. In an
untextured form, continuous filament yarns are
not posses a combination of good covering
power tactile qualities, comfort and a pleasing
7. appearance. Silk is a natural filament, synthetic
filament yarn is used to produce silk like effect.
Filament yarns are two types:-
a) Monofilament: Which containing one
filament. e.g. Silk.
b) Multifilament: Which contains two or more
filaments e.g. Nylon.
(ii) Staple or spun yarn
Yarn in which number of discontinuous fibres
are hold together generally by twist is called
staple yarn. Generally staple yarn consists of
short length fibre from 25mm to 180mm. To
produce the yarn from such kind of short fibres,
the fibres (carded or carded and combed)
should keep parallel and then wound together
by either clockwise or anti-clockwise twist.
The yarn which is made in this way is also
called spun yarn.
Staple yarns categorically have excellent tactile
qualities (handle, good covering power &
8. excellent comfort factor) and are aesthetically
pleasing. However, staple yarns as a group are
not as strong as uniform as continuous filament
yarns of equal linear density. Finally, because
staple fibres are processed as a mass rather than
individually, the number of fibres per yarn
cross-section varies considerably along the
yarn length. This condition limits the fineness
of spun yarn.
Spun yarns are two types:
a) Homogeneous: Which are spun from one
type of fibre e.g. 100% cotton yarn.
b) Blended: Which are spun from more than
one type of fibres e.g. cotton-polyester blend
yarns.
(iii) Modified continuous filament
The continuous filament yarns which are
textured or modified to change their
appearance and other properties, are called
modified continuous filament.
9. 2. Multi folded or plied yarns
They are made by twisting together two or
more single yarns. e.g. Sewing threads. The
yarn which has been plied by plying process is
called plied yarn. Plying process is done to
make the yarn strong and balanced.
3. Cabled yarn
Cabled yarns are made by twisting together two
or more multi folded yarns. e.g. Cords.
4. Gimped yarn
Gimped yarn is a type of yarn where a yarn
called core yarn is wrapped with another yarn
or filament. The yarn fed through at the
delivery rollers only is called core. Here, the
core yarn remains untwisted or intact, twist
only given to the yarns that are wrapping it.
Besides, the surrounding yarns can be
unwrapped.
10. 5. Complex yarn or core spun yarn:
In a complex yarn, either a continuous filament
core is surrounded by staple fibre or a spun
yarn or core is surrounded by continuous
filaments. There is a basic difference between
gimped yarn and core spun yarn. In case of
gimped yarn the core yarn is wrapped by
another yarn but in core spun yarn, the core
yarn is wrapped by fibre (not yarn).
Core spun yarns are two component structure
with core and sheath. Generally, continuous
filament yarn is used as core and the staple
fibre are used sheath covering. The core spun
yarn are used to enhance functional properties
of the fibres such as strength, durability and
stretch comfort. Polyester filaments are often
wrapped with a cotton outer layer in order to
provide the strength and resiliency of polyester,
along with the moisture absorbent and dye of
affinity of cotton.
6. Novelty or fancy yarn
11. Fancy or novelty yarns are of decorative
purpose. They are made by introducing spiral
forms of irregularity or hairiness into either
spun continuous filament yarn. e.g. chenille
yarn, loop yarn, slub yarn, snarl yarn. Novelty
yarns are usually uneven is size, varied in color
or modified appearance by their formation. Tin
single yarns, the irregularities may be caused
by inclusion of knots loops, slub etc. In plied
yarns, the irregularities may be affected by
variable delivery of one or more spun yarn
components or by twisting together dissimilar
single yarns.
7. Strength yarn
Yarn that have been programmed for extra
ordinary extensibility are known as strength
yarn. Most stretch yarn can be extended from
one of one half twice their normal or relaxed
length. The structures are not only highly
extensible but highly elastic as well.
12. 8. High bulk yarn or texturized yarn
In texurized yarn the filament have been
crimped regular pattern. It is also called bulk
yarn. A high bulk yarn is a staple or continuous
filament yarn, that has normal extensibility but
unusually high degree of loftiness or fullness.
These yarns retain their bulkiness under both
relaxed and stressed conditions. Great covering
power with little weight is possible in fabrics
composed of high bulk yarn..
9. Metallized yarn
Metllized yarns may be formed a metal wire
combined with textile, a gimped yarn
combined with metal or a core metal/plastic
wrapped with metal dust by the help of glue.
10. Combed yarn
Combed yarn is better in quality than carded
yarn. According to the technical parameter the
long length fibre is considered as better.
Because long fibre decrease hairiness in yarn,
13. give strength to the yarn and yarn become more
even. To obtain the long length fibre in yarn,
the short fibres should be removed. For this
purpose a processing is done called Combing.
So, the yarn which is obtained by combing
action is called combed yarn. In case of
combed yarn short fibre percent is low and yarn
is regular. Hence, after weaving or knitting the
fabric looks very even. As a result the price will
be more.
11. Carded yarn
Carded yarn is interior in quality as combing
action is not done here. Therefore, the strength
of the carded yarn is lower than combed yarn
and in carded yarn the percentage of short fibre
is high, that is why yarn will have more
hairiness. Hence, the fabric manufactured from
carded yarn will be uneven.
Yarn designation| Factors required for
yarn designation
14. According to Textile Institute, “Yarn may be
defined as a product of substantial length and
relatively small cross-section consisting of
fibre or filament with or without twist”.
To properly describe a specific yarn for
communication purpose, a great deal of
information is required. By using these
information, the structure and properties of a
yarn can be exposed entirely. The factors
which are required to express yarn structure
and properties wholly are called yarn
designation.
The factors are
1. Yarn count/Linear density
The linear density of the yarn should be
expressed. If the yarn is a ply or combination
yarn, the linear density of the individual
15. components and the resultant count should be
stated.
2. Direction and amount of twist
The direction of twist and frequency (amount)
should be identified in single yarn and in the
individual component in case of ply yarn.
3. The fibre content
The fibre content may be identified generally
and in case of blend, the proportion of the total
weight of the yarn. The physical properties of
the constituent fibres(length, crimp, fineness,
etc.)
4. The yarn constructional features
The construction of the yarn is staple or
continuous filament (single, ply or combine)
should be indicated.
5. No. of filament.
16. 6. No. of component in folding.
7. No. of component in cabling.
8. Strength and elongation.
Yarn Twist | Twist direction
Yarn Twist
According to Morton, “When a strand is
twisted the component fibres tend to take on a
spiral formation, the geometric perfection of
which depends on their original formation.”
According to Skinkle, “Twist is the measure of
the spiral turns given to a yarn in order to held
the constituent fibres or threads or threads
together.”
According to WIRA, “Twist may be defined as
the rotation about the yarn axis of any line
drawn on the yarn which was originally i.e.
before twisting parallel to the yarn axis”.
17. According to Textile Institute, “Twist is the
spiral disposition of the components of a thread
which is usually the result of relative rotation
of the two ends”.
Twist direction
The direction of twist is indicated the use of the
letters ‘S’ and ‘Z’ in accordance with the
following convention:
(a) S-twist: A single yarn has S twist when it
is held in the vertical position, the fibres
inclined to the axis of the yarn conform in
direction of slop to the central portion of the
letter S.
(b) Z-twist: The yarn has Z-twist if the fibres
inclined to the axis of the yarn conform in
direction of slope to the central portion of the
letter Z.
Amount of Twist | Importance of Twist
18. Amount of twist
The amount of twist means the number of turns
in unit length in a twisted yarn. If “n” be the
number of turns in “L” length of yarn, then
amount of twist will be n/L. Amount of twist is
expressed in -
a. Twist per inch (TPI)
b. Twist per meter (TPM)
c. Twist per centemeter (T.P.C.m)
Here, twist per inch means the number of turns
in unit inch and in the same way twist per meter
and twist per centimeter is the number of turns
in unit meter & unit centimeter. TPI of a yarn
is 40 means the number of turns in 1 inch length
of yarn is 40.
Amount of twist depends on the yarn count, for
which purpose the yarn will be used and on
the length of yarn. Without these the amount
of twist depends on the types of fabric i.e. for
19. soft surfaced fabrics slack twist is given and
such kind of yarn is called soft twisted yarn.
Importance of twist
a. Twist increase the tensile strength of yarn
as well as the strength of yarn.
b. The yarn shape becomes round i.e. shape
factor goes near 1 due to twist.
c. The inter-cohesion affinity of fibres
increases due to twist and do not open easily.
d. The more twist increased under the
constant value, the yarn become so strength.
Function of Twist in yarn structure | Why
twist is important for yarn
A question may arise why twist is given to yarn
or what is the function of twist. Actually twist
plays a vital role in yarn manufacturing which
is given below –
1. The main function of twist is to give a round
shape to the yarns, increase the strength of
yarn. As in sliver no twist is given, therefore it
20. is easy to open the fibre, but it is difficult in
case of roving or yarn.
2. Without twist a strand of fibres has very little
strength and in the first instance a yarn must
have sufficient tensile strength to withstand the
stresses of preparation and fabric manufacture.
3. The main function of twist is to give
coherence to the yarn. In order to develop
strength in a twisted strand of discontinuous
fibres and so resist breakage, the individual
fibres must grip each other when the strand is
stressed. This cohesion arises mainly from the
twist, which presses the fibres together as the
stretching force is applied and so developing
friction between adjacent fibres.
4. If the twist is low, the fibres can be made to
slide past one another, but if it is large they
cannot. The twist can be termed as twist angle
that means when twist angle is high, then yarn
21. strength is high. An experiment shows that,
when twist is increased then yarn strength
increases within a certain limit and at a point
called critical point the maximum strength of
yarn is obtained. But after critical point at the
end increasing the tension goes to the rupture
the strand by breaking the component fibres.
Yarn count| Types of counting system
Yarn Count | Types of count
Yarn count is a term used to express the
thickness of yarn. In spinning process, there
is a relation between the weight of the original
fibres and the length of yarn. This relation is
indicated as thickness. Thickness of yarn is
determined by the extent of drawing process
(varying draft) and designated by number. The
number is called count.
So, when we say what is yarn count? The
answer will be, yarn count is the weight per
unit length or length per unit weight which
expresses the fineness or coarseness of yarn.
22. According to Textile Institute, “Count, a
number indicating the mass per unit length or
the length per unit mass of yarn.
Types of count system
Basically, two types of yarn counting system:
1. Direct system
2. Indirect system.
Another system is classified as third type of
count and that is “Tex”. Tex is also called
Universal count. International Organization
for Standardization (ISO) fixed the
relationship between weight and length
for Tex. The greater the weight, the thicker the
yarn and Tex will be greater number. We will
discuss it under Direct system.
Direct System
In this system, the count of yarn expresses the
no of weight units in one length unit. Higher
23. the count, coarser the yarn. This system is
generally used for Man made fibre, jute, silk
etc.
Now, let’s see the how count is
mathematically calculated.
Let,
N = The yarn number or count.
W = The weight of the sample.
w = The unit of weight of the system.
L = The length of the sample.
l = The unit of length of the system.
Now, Count, N = (W×l)/L
Indirect System
In this system, the count of yarn is expresses
the no of length unit in one weight unit. Here,
when count is higher, then yarn will be finer.
The system is usually used for cotton,
worsted, metric, french, linen (wet spun) etc.
Let,
N = The yarn number or count.
24. W = The weight of the sample.
w = The unit of weight of the system.
L = The length of the sample.
l = The unit of length of the system.
Now, Count, N = (L×w)/(l×W)
Count in different system
There are many types of count which are
classified under direct and indirect system.
Various types of count in direct and indirect
system are as following:
Direct system
Tex: Count in the Tex system is the weight in
grams of 1000m or 1km of yarn. From an
example we will understand it easily.
If the weight of 3000meters yarn is 2.5grams,
then what will be the count in Tex for the yarn?
We know that Tex is calculated in direct
system. For direct system, Count, N = (W×l)/L
Where,
N = The yarn number or count.
W = The weight of the sample = 2.5gm
25. L = The length of the sample = 3000m
w = The unit of weight of the system = 1gm
l = The unit of length of the system = 1000m
Now, Count, N = (W×l)/L = (2.5×1000)/3000
= 0.83
So, count is 0.83Tex.
Denier: The number or count in the denier
system is the weight in grams of 9000m or 9km
of yarn.
Pounds per spindle: The yarn number or
count in the pound per spindle system is the
weight in pounds of 14400 yards of yarn. This
count is used for jute.
Millitex: Count in Millitex system is the
weight in milligram of 1km of yarn.
Kilotex: Count in the kilotex system is the
weight in kilogram of 1 km of yarn.
26. Wollen: Count in wollen system is the weight
in grain of 20 yards of yarn.
Indirect system
English count: The yarn count is defined as the
number of hanks of 840 yards per pound. We
should know that, the length of 840 yards yarn
is called 1 hank. By the same way, 2520 yards
yarn is equal to 3 hank.
If one pound of yarn contains 30 hanks of 840
yds, then in English system count will be 30
Ne. It is denoted by Ne. Here, length of the
30Ne yarn is (840×30) = 25200 yds as hank is
30 and unit length is 840yds.
For example, If the weight of 3000meters yarn
is 2.5grams, then what will be the English
count for the yarn?
We know that English count is calculated in
indirect system. For indirect system, Count, N
= (L×w)/(l×W)
Where,
N = The yarn number or count.
27. W = The weight of the sample = 2.5gm =
0.00551lb
L = The length of the sample = 3000m =
3270yds
w = The unit of weight of the system = 1lb
l = The unit of length of the system = 840yds
Now, Count, N = (L×w)/(l×W) = (3270×1)/
(840×0.00551) = 706.5 Ne.
So, count is 706.5Ne.
English count is used for cotton.
Metric: It is defined as the no of hanks(1000m)
per kg e.g. if one kg of yarn contains 40 hanks
of 1000m, then in metric system count will be
40 Nm. It is denoted by Nm.
Worsted: It is defined as the number of
hanks(560yds) per pound e.g. if one pound of
yarn contain 30 hanks of 560 yds, then in
worsted system count will be 30 worsted.
