Advance Weaving Technology

1. VIJAY PRAKASH
Uttar Pradesh Textile Technology Institute
(Earlier known as Government Central Textile Institute), Kanpur
Advance Weaving Technology
3/23/2020
1
Jet Weaving Machine

2. Subject Name : Advance Weaving Technology
Plan of Lecture
Lecture
no.
Title
1 Unit-4 Working principle of airjet weaving machine
2 Requirements of airjet loom
3 Weft measuring device
4 Weft tensioning device
5 Beat-up mechanism
6 Weft gripping, weft cutting
7 Nozzles
8 Quality of compressed air for airjet loom
3/23/2020
2

3. *
A.I.Amjad

4. Basic concepts of fluid carrier
• As compared to solid carriers, fluid carriers like water and air offer
considerably lower inertia as density of pure water is 1 g/cc at 40C
and that of dry air at sea level is 0.001275 g/cc at 00C.
• Just as potential energy can be stored in torsion rod of gripper loom,
so can energy be stored in fluid by compressing the same. Releasing
some of this energy at a suitable instant has proved to be an elegant
way of propelling a pick of weft.

5. Basic concepts of fluid carrier
• The released energy propels weft along with a certain amount of
fluid. However density of fluid as also of the weft yarn being very
low and the net mass of a pick of weft being in milligrams, both can
attain very high velocity within a short time which is well beyond
the scope of any solid carrier.
• Hence modern looms based on fluid propulsion systems offer
productivity twice as high as those attained by solid carriers. Indeed
shedding and beating up systems constitute the limiting factors
affecting productivity for fluid propulsion based machines.

6. A.I.Amjad
*Introduction of Jet Weaving
• In jet picking, the weft yarn is inserted by means of a fluid known as jet.
• The fluid used in jet-weaving may be air or water.
• The relative velocity between the jet and the weft thread produces a force
on the weft which results in its insertion in the shed.
• The air jet weaving machines are supplied with compressed air from a
central compressor in the weave room or are equipped with individual
built -in compressors.
• The water jet weaving machines are equipped with individual injection
pumps to pressurize water supplied from the water main; waste water is
discharged into a drain.

7. A.I.Amjad
*General Considerations
• To achieve acceleration of
either compressed air or
pressurized water together with
the leading end of the weft yarn
a nozzle is used.

8. • The mass of insertion medium to be accelerated is very small, relative to
the shuttle, rapier or projectile weaving machines, which allows high
running speeds.
• Mass of the fluid is about 1.5g.
• Unlike the rapier or projectile insertion systems, there are not many
mechanically moving parts to control and insert the weft yarn.
• Technical requirements of the fluid are important temperature, humidity,
impurity content etc. :
General Considerations

9. *General Considerations
• As the tractive force applied to the weft is not very high, it must be
prepared for picking by a metering device.
• In the majority of the jet weaving machines the picking system is fitted
only on one side of the machine (single-sided picking) and
• The picking system is fixed firmly to the machine frame so that the beat-
up mechanism carries only the reed and/or the air duct.

10. *Weft Insertion through
Jet Looms
1 cross wound cone, 2 guide eye
and 3 tensioner,
device (measures
7 metering
the necessary
pick length of the weft thread). 9
holders to retain the weft thread
after picking,
water or
10 nozzle. The
air are supplied to
through tube T
A — the reed, B — the warp
sheet, C — the woven fabric, D
— the weft cutter, E and F — the
leno weave serving to reinforce
the fabric selvedges

11. *Warp Passage of Jet
Looms
The passage of the warp through a jet loom (Elitex air-jet loom)
The weft-insertion medium
does not require support.
The passage of the warp
through the machine can be
modified, so that a
substantial saving in floor
space will be achieved.
The cloth roller is situated
under the warp at the back
of the loom as illustrated.
This makes servicing of the
warp, weft, and cloth from
the back alley easier.