Pitch Date: December 22, 2019

1. Afsara Mostary Moon
ID: 1721045
Mohammad Naim Hassan
Assistant Professor
Dept. of Textile Engineering, KUET
PRESENTING TO
PRESENTING BY
Kh Nurul Anam
ID: 1721046
Md. Ahsanul Mobin
ID: 1721048
Sajidur Rahman
ID: 1721049
Md. Nadim Mahmud
ID: 1721050
YARN TWIST

2. OUTLINE OF PRESENTATION
• Introduction
• What is Yarn Twist?
• Objectives of Yarn Twisting
• Types Of Twist
• Yarn Twist Parameters
• Twist Direction
• Twist Factor or Twist Multiplier
• Twist Level (turns/unit length)
• Methods of Measuring Yarn Twist
• Relation Between Twist and Yarn Strength
• Reference
• Conclusion

3. WHAT IS YARN TWIST?
According to Morton, “When a strand is twisted the component fibers 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”.
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”.

4. OBJECTIVES OF YARN TWISTING
• To hold the staple fibers together.
• To increase the yarn strength.
• To increase yarn evenness.
• Finer yarn has more twists.

5. TYPES OF TWIST
Real twist:
To insert a real twist into a length of yarn, one end of
the yarn should be rotated relative to the other end,
Spun yarns usually have real twist, which holds the
fibres together in the yarn. as indicated in figure (a)
False twist:
When inserting false twist into a length of yarn, both ends of the yarn are clamped, usually by rollers,
and twist is inserted with a false twister between the clamping points, as indicated in figure (b)

6. YARN TWIST PARAMETERS
In practice, yarn twist is described using three main parameters:
• Twist Direction
• Twist Factor or Twist Multiplier
• Twist Level (turns/unit length)

7. TWIST DIRECTION
S Twist:
The fibers from a helical angle at the yarn surface when yarn is twisted in anticlockwise direction. This angle
conforms to the middle part of the letter “S” and, therefore, it is termed as “S” twist.
Z Twist:
The fibers from a helical angle at the yarn surface when yarn is twisted in clockwise direction. This angle conforms
to the middle part of the letter “Z” and, therefore, it is known as “Z” twist.

8. TWIST FACTOR/TWIST MULTIPLIER
The twist factor or twist multiplier is a measure of twist, which accounts for the yarn
radius as well as the twist level.
TM=TPC√tex or TM=TPI÷√Ne

9. TWIST LEVEL
Twist level expressed in the number of turns per unit length.
hT = 1
Here ,
h = one turn of twist
T = twist level

10. EXPRESSION OF TWIST
Twist amount is expressed in –
• TPI (Twist per inch)
• TPM (Twist per meter)
• TPCm ( Twist per centimeter)
Amount of Twist
The number of turns or twists per unit length of the twisted yarn is
called amount of twist.

11. METHODS OF MEASURING YARN TWIST
• Single untwist method
• Fibre straightened method
• Single twist-untwist method
• Double twist-untwist method
• Multiple twist –untwist method
For Plied Yarns –
• Ordinary twist tester
• Automatic twist tester
• Take up twist tester(for plied yarns)
• The quadrant twist tester

12. RELATION BETWEEN TWIST AND YARN STRENGTH
An increase in the amount of twist produces an increase in the yarn strength. This effect holds only up to a
certain point beyond which further increase in twist causes the yarn to become weaker & finally breakage of
yarn.

13. TWIST TESTER
Yarn Twist Tester, to determine yarn twist in single or plied yarns, quadrant type with auto stop & reverse
for conventional or untwist/re-twist methods.

14. REFERENCE
https://articletrade.blogspot.com/2014/04/importance-of-geometry-of-twisted-yarns.html
https://textilelearner.blogspot.com/2012/01/yarn-twist-twist-direction-types-of.html
https://textilestudycenter.com/study-of-twist/
https://www.fiber2apparel.com/2018/05/yarn-twist-types-direction-textile-industry.html
https://www.swicofil.com/commerce/basic-information/yarn-manual/twist-direction
http://textilestudy365.blogspot.com/2017/05/yarn-twist-types-of-yarn-twist.html
https://textilestudycenter.com/study-of-twist/