This document discusses rotor spinning and the importance of the navel component. It covers the history of rotor spinning, the key components of a rotor spinning system including the opening roller, rotor, and navel. The navel plays a crucial role by inserting twist into the yarn and determining yarn characteristics. Different navel designs and parameters like the number of notches, surface geometry, and radius can impact properties of the spun yarn such as evenness, imperfections, hairiness, tenacity, and elongation. Fiber parameters and blend also influence navel selection for rotor spinning.

2. OVERVIEW
 Rotor spinning- earlier and today
 Navel selection- navel and fibre
parameters
 Properties of navel
 Function of navel
 Effect of navel on different yarn
properties
 Latest navel designs

3. ROTOR SPINNING – EARLIER
AND TODAY

4. Modern rotor Vs. conventional
Rotor
 Regularity of appearance
 Reduced imperfection count
 More abrasion resistant
 More extensible
 Less hairy

5. Components in OE–rotor
spinning
 Opening roller
 Rotor
 Navel

6. Importance of Navel
 Twist insertion in yarn.
 Decides the yarn characteristics.

7. Working Principle of navel

8. PROPERTIES THE NAVEL
MUST POSSES
 Maximum service life
 Minimum heat generation.
 Reduced fly and dust generation.
 Soft as a steel navel to the yarn.
 Higher rotor speed.

9. NAVEL SELECTION – fibre
parameters
 Natural fibres.
 Synthetic fibres.
 Fibres blend.

17. NAVEL SELECTION- Navel
parameters
 Number of notches
 Form of notches
 Structure of navel surface
 Surface geometry of navel
 Radius
 Grooves
 Rotor speed

18. Draw off nozzles shapes
 Smooth.
 Notches.
 Spirals.
 Whirl inserts.

20. Effect of navel on different yarn
properties
 Evenness (U%)
 Yarn imperfection (thin-thick places and
neps)
 Hairiness (H)
 Tenacity (cN/tex)
 Elongation (%)