This document discusses yarn twist, which is the spiral arrangement of fibers around a yarn's axis that binds the fibers together and contributes to the yarn's strength. There are two types of twist direction: S-twist and Z-twist. The amount and direction of twist impacts a yarn's appearance, strength, and other properties. Twisting fibers increases yarn strength by holding them together tightly. Both higher and lower twist levels can affect a yarn's absorbency, aesthetic effects, and tensile properties. The objectives and importance of twisting fibers into yarn include binding fibers, increasing strength and evenness, and shaping the yarn into a round form.

1. Submitted To,
Alamgir Hossain
Lecturer
Department Of T.E
Submitted By,
Ferdous Ahmed Shohan
ID: 171-23-4986
Section: A

2. YARN TWIST

3. WOODGROVE
BANK
WHAT IS YARN
TWIST?
Twist is the spiral arrangement of the fibers
around the axis of the yarn. The twist binds
the fibers together and also contributes to the
strength of the yarn. The amount of twist
inserted in a yarn defines the appearance and
the strength of the yarn. The number of twists
is referred to as turns per inch.

4. WOODGROVE
BANK
TWIST DIRECTION
Two types of Twist
Direction
S- Twist
Z- Twist

5. WOODGROVE
BANK
S - TWIST TWIST DIRECTION
S twist When a
twisted yarn is held
vertically, the
individual filaments
are appearing in this
case as the diagonal
in the letter "S". The
same can apply if
several yarns have
been twisted together:
their combined twist
can again appear as
the diagonal of the
letter "S".
5

6. WOODGROVE
BANK
Z - TWIST TWIST DIRECTION
Z twist When a
twisted yarn is held
vertically, the
individual filaments
are appearing in this
case as the diagonal
in the letter "Z". The
same can apply if
several yarns have
been twisted together:
their combined twist
can again appear as
the diagonal of the
letter "Z"
6

7. WOODGROVE
BANK
FUNCTION OF TWIST IN YARN STRUCTURE
• 1) To increase the yarn strength in
order to withstand the stress of
preparation and fabric manufacture.
• 2) The main function of twist is to
give coherence to the yarn.
• 3)If the twist is low , the fibers can
be made to slide past one another,
but if it is large the increasing
tension would break the fibers.

8. WOODGROVE
BANK
RELATION BETWEEN YARN STRENGTH & YARN
TWIST
Up to a certain point if the twist increase, the
strength of the yarn will be increase. Further
increase in twist the yarn will be weaker & finally
broken

9. WOODGROVE
BANK
OBJECTIVES OF YARN TWISTING
To hold the staple fibers together.
To increase the yarn strength.
To increase yarn evenness.
Finer yarn has more twists.

10. WOODGROVE
BANK
EFFECTS OF TWIST ON YARN & FABRIC
PROPERTIES
10
In the case of moisture absorption : High twist holds
the fibers tight thus restricting water to enter. On the
other hand low twist yarn is used where absorbency is
required.
In the case of aesthetic effects : 1) The level of twist in
yarn alters its appearance both by changing the
thickness and light reflecting properties.
2) Different patterns can be produced in a fabric by
using similar yarns but with different twist levels.

11. WOODGROVE
BANK
IMPORTANCE OF TWIST
11
1)The shape of yarn become round.
2) Increase tensile properties of yarn due to twist.
3) The inter-cohesion affinity of fibers increases due to
twist and don't open the fibers easily.

12. THANK YOU
WOODGROVE
BANK