1) Multiphase weaving incorporates two principles - filling direction shed wave principle and warp direction shed wave principle. It allows for multiple sheds to be opened simultaneously across the width of the fabric for high speed weft insertion. 2) There are two types of multiphase looms - circular and flat. Circular looms use an electromagnetic or rack and pinion system to drive the shuttle in a circular motion. Flat looms form multiple linear sheds across the width. 3) New developments in multiphase looms include the use of air jet nozzles to insert multiple wefts simultaneously and oscillating reeds that help drive the weft carriers and perform beat-up. Modular designs

1. OCITI INNOCENT OLUR BU/UG/2016/1725
FACULTY OF ENGINEERING
DEPARTMENT OF TEXTILE AND GINNING ENGINEERING
FABRIC FORMING TECHNOLOGY III
STUDENT’S NAME: OCITI INNOCENT OLUR
REG NO.: BU/UG/2016/1725
LECTURED BY:MADAMYVONNE
Assignment question:
Write a review article on the following in multiphase weaving;
a. Principles
b. Categories
c. How they work
d. New developments

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Introduction
Multiphase weaving machine is a shuttle-less loom with multi-linear shed formation. The first
commercial multiphase loom was demonstrated in 1971. Although the multiphase loom offers highest
weft insertion rate among all shuttle-less looms, it has not yet made an impact in the world textile trade
due to many design limitations. All the models of multiphase looms are producing plain weave only.
Although a major share of the world’s fabric production is plain weave, it is surprising that the
multiphase loom has not become popular, probably due to the lack of versatility, design limitation and
problems in correcting at loose pick at the time of a weft break (Behera, 1994).
Principle of operation
Multiphase weaving incorporates two principles:
a) Filling direction shed wave principle and
b) Warp direction shed wave principle.
Filling direction shed wave principle
In this principle, a number of sheds in weft direction are opened subsequently for the insertion of the
weft.
Sheds are arranged wave-like from one side to another so that weft carrier slides into each shed.
The machine may be rectangular (flat) or circular.
As the weft carrier enters one position of the warp, the shed is formed; as the carrier leaves the area, the
shed changes.

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It may be as shown in the figure below;
The action may occur simultaneously across the width of the warp several times. As a result, at any
moment, there are several shuttles in the shed, each carrying a different yarn.
Disadvantages:
 Missing picks cannot be easily repaired.
 Warp and weft threads are not perfectly perpendicular to each other.
Warp direction shed wave principle
A number of sheds are opened in the warp direction at the same time for the weft insertion.
These sheds are opened one after another in the warp direction; however, there are several sheds that are
open at any given time.
Each shed extends across the full width of the warp and moves in the warp direction. The weft yarn can
be inserted in a manner similar to that of conventional weaving systems.
This concept is called sequential-shed principle or multi-linear shed principle(M8300).
The warp ends pass over the rotating weaving rotor; the sheds are formed consecutively on its
circumference by shed forming elements.
Motion of the rotor causes the shed forming by shed forming elements to open the shed one after
another. The weft yarn is inserted by low pressure compressed air through the channel across the full
width of the fabric.
Four picks can be inserted simultaneously. The yarn velocity is 20m/s at an insertion rate of 5000m/min.
Beat up combs are located on the weaving rotor between the rows of shed forming elements perform the
function of the conventional reed (Onder, 2012).
Types of multiphase weaving machine
They are of two types: -
1. Circular Multiphase Loom.
2. Flat Multiphase Loom.

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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. A circular multiphase
loom can be depicted as below.
A series of electromagnetic blocks is rotated on a motor driven
main center shaft. The electromagnets are prevented by the
intervening warp shed, which is tensioned and thus supports the
shuttle.
The shuttle is supported by the fixed reed that holds the warp
ends at the desired spacing.
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. (Emdad, 2014)
Wave shedding mechanism
Warp shed is divided into segments.
Each shuttle runs in its own shed.
Cam controls the heald frame or wire segments from inside via pushrods.
Only plain and twill weave are possible.
Heald is connected elastically, by way of an elastic traction element locked to the fixed part of the loom.
Healds of each segment are slowly locked to a single connection by a spring catch connector, which is
itself connected to the end of a cam-controlled operating lever.
Each cam controls an independent set of connecting block thus an independent part of a heald frame.
Filling Insertion of Circular loom
These are categorized into: -
a. Rack and Pinion shuttle drive;
The harness operates vertically and in front of the reed.

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A series of rotating pinions are situated round the loom as below.
These pinions engage with a rack on the underside
of the shuttle, which is thus traverses round the
loom.
The teeth in the pinions are shaped that the ends in
the bottom warp sheet easily rest in the clearance
area between the teeth and pegs in the shuttle rack.
b. Electromagnetic shuttle drive
This is set up in the from of a magnetic field by which
the shuttle is moved.
A rotating electromagnet holds the shuttle firmly
through the warp ends of the inner shed and carries it
when it rotates.
Flat Multiphase Loom
i. Shed formation in Flat Multiphase Loom:
This can be shown diagrammatically as below;
ii. Weft Insertion in Flat Multiphase Loom
The Contis-C2 and Nuovo Pignone-TZP looms use positive drive from the roller on an endless chain
track fitting into the depression in carriers.
In Ruti-6000 the weft carrier is driven by reed dents which applies pressure to the rear inclined
surface of the weft carriers.
iii. Beat-up in Flat Multiphase Loom:
Beat -up is done by oscillating reeds in case of flat multiphase loom. These kinds of reeds also aid in
the weft carrier drive.

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New developments in Multiphase weaving
i. Weft insertion
The channel in the shed forming elements guide in insertion of weft. The weft is inserted by nozzles
that are similar to Air jet weaving. Additional nozzles between shed forming elements further support
the weft. Four wefts are inserted at a time. The weft measuring, clamping, cutting, sensing and
controlling are similar to air jet machines (Ahmed, 2015).
ii. Beat up.
The combs located behind shed forming elements perform the function of conventional reed. The lower
shed, which rises after insertion of the weft, lift the weft out of channel over the entire weaving width,
The beat up comb then catches the weft and beats up.
The modular design concept adopted has helped to change warp beam within 20 minutes. The warp
beams of up to 1600mm diameter can be used. The inclusion of batching motion for cloth winding has
reduced change intervals.
Many machines were in operation since 1997 and this might be the machine for the future (Ahmed,
2015).

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REFERENCES
1. Ahmed, A. (2015). Weaving process and advancement in weft insertion system. Advanced weft systems,
42-44.
2. Behera,P. K. (1994). Developments in Weaving Machines. Indian Journal of Fibre and Textile Research,
172-176.
3. Emdad, M. I. (2014). Multiphase: A new Concept of Weaving. India: 2014, 002-005.
4. Hossain., M. Y. (2015). Weft Insertion by Multiphase Circular Loom. Bangladesh:Green University of
Bangladesh.
5. Onder, P. D. (2012). Weaving Technology II. Frankfurt,Germany.