Transcript Weft insertion rate

Weft insertion rate
Group members:
Annas azwany muzamil (2014877152)
Mardhiah husnoruddin (2014668478)
Nur atiqah sahak (2014279052)
Nur miza asyran mohd ali henipah (2014491026)
Siti nur mazleen kamaruzaman (2014478128)
What is weft insertion?
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After each shed change, the weft yarn is inserted through the
shed.
These weft yarn can be different in color, weight etc and
selection mechanism is used for this purpose.
What is weft insertion rate?
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Weft insertion rate is defined according to the
following formula which is:
WIR = PR (m/min)
Where
WIR = weft insertion rate
P = loom speed in picks/min
R = reed width in metre.
Therefore it can be said that weft insertion
rate is loom speed in picks/min multiply by
reed width.
Objectives
 Increasing
productivity.
 Improving fabric quality.
 Reducing the number of operations and
operating through automation.
 Use of electronics and microprocessors for
better monitoring of various mechanism to
achieve the above objectives and reducing
the cost of production.
Comparison of different types
of looms
Loom
Weft Insertion Rate
Conventional Powerloom
200 Mts / Min
High Speed Automatic Loom
300 - 400 Mts / Min
Rapier Loom
1000 - 1400 Mts / Min
Projectile Loom
1200 - 1500 Mts / Min
Air Jet Loom
1500 - 2000 Mts / Min
Multiphase Loom
5000 Mts / Min
PROJECTILE LOOMS
ITMA 1955 at Brussels
 First Sulzer machine with reed width of 216 cm.
 Maximum speed of 280 picks/min
 With a WIR (weft insertion rate) of about 600 m/min.
ITMA 1971 in Paris
 Further developments with the first 540 cm wide six-color
prototype machine.(1969)
 The projectile loom has a width range of 185 – 540 cm
 Maximum speed of 470 rpm.
 With a WIR (weft insertion rate) of 840 m/ min.
NOW
 The projectile machines now are running with a WIR (weft
insertion rate) of 1540 m/min without any further change in
the working width.
Rapier Loom
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1844 – Development of shuttles loom starting with rapier loom
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Present weft insertion rate up to 1, 500 m/min
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The outstanding feature of flexible rapier machine is its
significant increase in weft insertion rate, greater reed width
(460cm), versatility and adaptability.
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The weft insertion elements have been made smaller and lighter
in weight.
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This new lightweight guided gripper version of shuttless enables
higher speeds, and since the easier presentation into the gripper
clamp requires less filling tension, the number of filling stops is
reduced. The light gripper is also smaller, which results in a
smoother entrance of the gripper in the shed, ensures less friction
on the warp yarns thus reduces the warp breaks.
AIRJET LOOMS
1953
 The production time is at the same as projectile weaving.
1968
 Air jet looms running with relay nozzle, spaced at intervals
of 40-80cm.
Further development
 Increased speeds and width, greater patterning possibility,
more electronic control and broader application
versatility.
Now
 Machine width is increased dramatically up to 213 inch
and WIR (weft insertion rate) 2500 m/min.
 The machine speed range from 500 to 1200 rpm.
MULTIPHASE LOOM
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M8300 multi-phase weaving machine (Sulzer Textil) – whereby
the weft insertion rate has been tripled.
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The M8300 is used in the production of standard fabrics, which
account for about two-thirds of all fabrics produced for the
global market with a weft insertion rate of over 5000 m/min.
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During weft insertion, it is first subjected to extreme
acceleration and then sharp deceleration. It is loaded almost
to breaking point. However, not only the yarns, but also the
mechanisms of the machines are approaching their stress
limits, so that single phase weaving can hardly be
accelerated further. The central problem of high weft velocity
can only be solved in a multi-phase system, where several
weft threads are inserted simultaneously.
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For example, simultaneous insertion of four wefts at a velocity
of 1250 m/min results in a weft insertion rate of 5000 m/min. A
shed is needed for each weft, and so at the same time four
open sheds must also be available.
CONCLUSION
 As
a conclusion, the machine that offers
highest insertion rate among all shuttleless
loom is multiphase loom but it has not yet
capturing market. This is because it has
another disadvantages which is less versatility,
design limitation and problems in correcting a
loose pick at the time of weft break.