This document compares ring spinning and rotor spinning methods of yarn formation. It discusses that rotor spinning is a more recent method that omits the step of forming a roving. In rotor spinning, fibers are fed into a rotary beater and deposited onto the sides of a rotating disc called a rotor, where they are twisted without requiring package rotation. Rotor spinning allows for higher twisting speeds with lower power usage compared to ring spinning. It provides characteristics like higher productivity, larger sliver/package sizes, less power consumption, and more automation/flexibility. The document provides details on the parts of a rotor spinning machine and compares various parameters of ring-spun and rotor-spun yarns.

1. The Rotor spinning & a comparison
between ring and rotor spinning-yarn
Md. Nakib-Ul-Hasan
Lecturer
Dept. of Textile Engineering
Green University of Bangladesh

2. Rotor spinning
Rotor Spinning is a more recent method of yarn formation compared to
Ring Spinning. The first functioning of rotor spinning, machine was
presented at the ITMA in 1967. Yarn spinning according to the rotor
spinning principle predominates for all non conventional spinning
methods. It omits the step of forming a roving. After drafting, the sliver
is fed into a rotary beater. This device ensures that the fibers are beaten
into a thin supply which enters a duct and gets deposited on the sides of
the disc(rotor).The transportation of the fibers is achieved through air
currents.
This is a form of open-end spinning where twist is introduced into the
yarn without the need for package rotation Allowing for higher twisting
speeds with a relatively low power cost. In rotor spinning a continuous
supply of fibres is delivered from delivery rollers off a drafting system or
from an opening unit.

3. Characteristics
• Higher Productivity
• Large Sliver Can
• Large Final Package
• Less Power Consumption
• Automation
• Flexibility of spinning component
• Handling count range

4. Feed roller
Feed trough
Opening roller
Naval
Feed tube
Rotor
Rotor groove
Withdrawal
roller
Important parts of a rotor spinning machine

5. Passage diagram of a Rotor machine

6. Tasks of the Rotor Spinning Machine
 Opening almost to individual
fibers (fiber separation)
 Cleaning
 Homogenizing through back
doubling
 Combining i.e. forming a
coherent linear strand from
individual fibers
 Ordering (the fibers in the
strand must have an orientation
as far as possible in the
longitudinal direction)
 Improving evenness through
back-doubling
 Imparting strength by twisting
 Winding
Opening
Cleaning
Homogenizing
Combining
Ordering
Back-doubling
Twisting

7. Technical Data of Rotor Spinning Machine:
• Number of spinning positions up to 220 per m/c
• Count range 12- 125 Tex (5 – 50 Ne)
• Draft 25- 400
• Rotation speed of opening roller 6000- 11000 rpm
• Rotation speed of rotor up to 120000 rpm
• Rotor diameter 32 -65 mm
• Delivery speed up to 200 m/ min
• Package mass up to 5 kg
• Angle of taper 2° - 4° 20’
• Winding angle 29° – 45°

8. Rotor Spinning Machine

11. Input Material Processing Machine Output Materials
Blow Room
Carding
Pre-Comb Drawing
Lap Former
Combing
Finisher Drawing
Simplex/ Speed Frame
Ring Frame
Winding
Lap / Chute
Card Sliver
Drawn Sliver
Lap
Comb Sliver
Drawing Sliver
Roving
Yarn
Large Yarn Package
Raw Cotton
Lap / Chute
Card Sliver
Drawn Sliver
Lap
Comb Sliver
Drawn Sliver
Roving
Yarn
Flow Chart of Conventional Comb Yarn

12. Blow Room
Carding
Breaker Drawing
Finisher Drawing
Rotor
Lap / Chute
Card Sliver
Drawn Sliver
Drawing Sliver
Rotor Yarn
Raw Cotton
Lap / Chute
Card Sliver
Drawn Sliver
Drawn Sliver
Input Material Processing Machines Output Materials
Flow Chart of Conventional Rotor Yarn

13. Ring Sp Ring Spinning Rotor Spin Rotor Spinning
Bobbin rotates constantly for insertion of
twist
Spool does not need to be rotated to insert
twist
Cannot handle spools of bigger size Much larger spools can be wound
Can spin finer yarns (up to 20m/min) 3-5 times faster than ring spinning
(200m/min)
Uniform and strong yarn Uniform but flexible yarn with better dye
ability
Combed yarns (finer) Carded yarns (coarser)
Yarns for varied applications Yarns for heavier fabrics such as denims,
towels and poplins
Stronger 20% more twisted but 15-20% weaker as
the yarn is coarser
Suitable for all staple fibres Not suitable for man-made staple fibre
spinning except rayon as the fibre finish
clogs the rotor
Ring Vs Rotor spinning system

14. Advantages over ring spun yarn
• Better CV% of strength
• Higher elongation at break
• Better mass irregularity ( over short lengths)
• Lower imperfection index
• Greater volume
• Higher abrasion resistance
• Higher stiffness
• Harder Handle
• Less power consumption
• Lower energy consumption with productivity
Rotor spun yarn Vs Ring spun yarn
Disadvantages over ring spun yarn
• Breaking strength lower than ring spun Yarn
• Less yarn count range
• Possible yarn counts rotor Ne 3 – 60 and Ring Ne 6 – 200

15. Comparison between Ring and Rotor yarn [20 Ne]
Parameters Ring yarn (Card) Rotor yarn
Tenacity (cN/Tex) 17.5 15.1
CSP 2550 1830
Elongation % 3.75 4.35
TPI 14.23 18.31
Uster U% 9.774 9.41
CVm% [1cm] 12.412 11.872
CVm% [3m] 2.882 2.91
Thin [-40%]/Km 20.687 36.56
Thick [+35%] 446.25 178.75
Thick [+50%] 48.125 5
Neps [+200%] 60.3125 26.25
Hairiness Index [H] 7.21 4.65
Note: This experimental data is an average test result out of 8-10 tests. The tests were
done at The Delta Spinning mills Ltd.

17. Garments

18. Thank You