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? 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? Weft insertion rate is defined according to the

following formula which is:WIR = PR (m/min)

WhereWIR = weft insertion rateP = loom speed in picks/minR = 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 LOOMSITMA 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 1844 – Development of shuttles loom starting with rapier loom

Present weft insertion rate up to 1, 500 m/min

The outstanding feature of flexible rapier machine is its significant increase in weft insertion rate, greater reed width (460cm), versatility and adaptability.

The weft insertion elements have been made smaller and lighter in weight.

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 M8300 multi-phase weaving machine (Sulzer Textil) –

whereby the weft insertion rate has been tripled.

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.

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.

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.