Welcome To My Presentation

Presentation ON “Weft Insertion By Multiphase

Circular Loom”

Sunday, April 19, 2015

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Presented By-

NAME:- ID No.

1. Md. Yousuf Hossain. 120103063

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Multiphase Loom:

Continuous weft insertion occurs in multiphase loom.

Required an ever-changing warp shed, which is

sometimes called wave-shedding.

There are usually four but occasionally six sets of

sectional harness for each shuttle, and each set

requires a cam unit to drive the harness.

In circular loom each cam unit is mounted on it’s own

short shaft.

Since each shaft must be connected to its adjacent

shafts by bevel gears.

Four sets of harness is required for 2/2 twill.

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Circular Multiphase Loom:

Two beams are used to supply the warp, which passes round the back rests and is then spread into circular form by a series of closed reeds. The warp shed is formed from this point.

Flat Multiphase Loom:

These looms are also unsuitable for the weaving of continuous filament yarns and they have added problem of stopping the loom in event of a weft break.

Multiphase looms are two types-

1. Circular Multiphase Loom

2. Flat Multiphase Loom

Mechanism (Weft insertion) of circular multiphase

loom:

Two beams are used to supply the warp, which passes

round the back rests and is then spread into circular

form by a series of closed reeds.

The warp shed is formed from this point.

A series of electromagnetic blocks is rotated on a

motor driven main center shaft. The electromagnets is

prevented by the intervening warp shed, which is

tensioned and thus supports the shuttle.

The shuttle is also supported by the fixed reed that

holds the warp ends at the desired spacing.

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Mechanism (Weft insertion) of circular multiphase

loom:

Beat-up is achieved by a spiked wheel mounted on an

antenna trailing behind the shuttle.

The spikes pick up the trailing weft and finally press it

into the cloth fell.

The work of the temple is done by a fixed ring, which

prevents early contraction of the cloth.

The take up motion is mounted in a high position and

the loom thus require a lofty room or space on two

floors, one above the other.

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Electromagnetic shuttle drive:

An arrangement showing eight shuttles equally spaced round the loom is shown in fig 2. The appropriate positions of 32 pairs of harness are included.

The continuous lines represent the harness that controls one set of alternate ends (odd end) and the dotted lines show the position of the other (even) end.

The electromagnets attract the metal shuttles, which thus follow the magnets in a circular path.

Attraction of the shuttles into physical contact with the electromagnets is prevented by the intervening warp shed, which is tensioned and thus supports the shuttle.

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Wave shed and electromagnetic shuttle drive-

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Rack and pinion shuttle drive:

• The harnesses operate vertically and in front of the

reed.

• A series of rotating pinions is situated round the loom.

• These pinions engage with a rack on the underside of

the shuttle, which is thus traverse round the loom.

• The teeth in the pinions are so shaped that the ends in

the bottom warp sheet easily rest in the clearance area

between the teeth and pegs in the shuttle rack.

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Rack and pinion shuttle drive-

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Beat-up Mechanism:

Beat-up is achieved by a spiked wheel mounted

on an antenna trailing behind the shuttle.

The spikes penetrate the warp sheet as shown in

figure 4.

This causes the wheel that is mounted on the

antenna arm to turn so that the spikes pick up the

trailing weft and finally press it into the cloth fell.

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Beat-up Mechanism-

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Features Of Multiphase Circular Loom:

Heavy reciprocating parts and a precision system of

shuttle.

Medium and coarse fabrics are produced.

Metallic shuttle propulsion by magnetic block and

pinion.

Wave shed is produced and shed is vertical.

Heald frames are horizontal.

For plain weave 32 harness are used.

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Features Of Multiphase Circular Loom:

In circular loom 8 shuttles may simultaneously be

employed for weaving.

Split harness are used for shedding.

Complete rotary motion is in line with weft knitting

machine.

Reed is fixed and it controls the warp spacing.

Rotating spiked wheel is used for beating up.

Multiple warp beam are simultaneously used.

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Thanks Everyone For Watching My

Presentation

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