AIR JET

.. without taking more time i m entering more recomanded notes regarding ur sylbus .








AIR JET spinning system

 

Raw Material Requirements

Synthetic fibres

Blends of synthetic fibres

Blends of synthetic fibres with cotton

Pure cotton only in combed form

All yarn properties are improved with long and fine fibres

The fibre should have-

1. High strength
2. Fairly high fibre to fibre friction
3. Low bending stiffness
4. Low resistance to twist
5. Small proportion of short fibres
6. 
   
   
   
   
   
   Fibre parameters in order of importance in Air Jet spinning
   1. Fibre length and length uniformity                     2. Fibre fineness
   3. Strength and elongation                          4. Cleanliness
   5. Fibre friction
   1. Fibre length & length uniformity
   A long fibre can easily generate adequate number of wraps around the core for structural integrity ------- Length should be at lkeast 38 mm
   2. Fineness
   Min numbers of fibres required in yarn cross section is slightly more (10-20%) than ring spg. Minimum 70 – 80 fibres are required in the X-section to fom yarn
   Fine fibres will have less bending and flexural rigidity
   He preferred fineness is 1.2 – 1.5 denier
   3. Fibre strength & Elongation
   Fibre strength has a positive influence on air jet yarn strength. Yarn strength increases with fibre tenacity due to –
7. Stronger wrapping effect. Increased pressure on the core under tension
8. Increase in core fibre tenacity

Under longitudinal stress, the binding fibres get elongated and compress the core more intensively during spinning. So fibres with higher elongational level is preferred

4. Fibre cleanliness

Trash is a hinderance as it creats problem in the free movement and rotation of yarn in narrow yarn tube of twist jets.

The abrasive effect of microdust can damage the machine at high rotational speeds.

5. Fibre friction

 High level of fibre to fibre friction is required

Increased cohesion due to high friction reduces breakage

Polyester is highly suitable for air jet as friction is very

Considering all the above required properties POLYESTER is the most suitable fibre for Air Jet spinning as it has

•           High tenacity

•           Elongation (5 times than cotton)

•           Low flexural, bending (1.8 times less than cotton) and torsional (2.4 times less than cotton) rigidity

VISCOSE and Acrylic can also be suxccessfully spun either 100% or in blended form.