Present Condition/Scenario of Modern Loom in Bangladesh. Modern Loom in Bangladesh

1. GREEN UNIVERSITY OF BANGLADESH
Department Of Textile
ASSIGNMENT
Remarks:
Course Code : TE 302
Course Title : Fabric Manufacturing II
Submitted By:
Name : Md Rakibul Hassan
ID : 183014057
Section : E1
Department : Textile
Date Of Submission : 19-09-2020
Assignment Topic : Present Condition/Scenario of Modern Loom in
Bangladesh.
Submitted to:
Name : Ms. Suraiya Ireen
Designation : Lecturer
Department : Textile

2. Present Condition / Scenario Of Modern Loom In Bangladesh
Introduction:
In weaving technology, modern looms means shuttle less loom. During the 20th century, this type of
loom machine has started to develop. There are various types of modern loom machines used in
weaving factory. Modern looms still weave by repeating in sequence the operations of shedding,
picking, and beating in, but within that framework there has been considerable development during
the 20th century. Several new types of loom have come into industrial use, whereas older types have
been refined and their scope extended. Two main influences have been the rising cost of labour and
the increasing use of synthetic continuous-filament yarns. The first has led to an increase in automatic
control, in automatic handling of yarn packages, and in the use of larger packages; the second, to
greater precision and finish in loom construction, because deficiency in these qualities is readily
reflected in the quality of the cloth made from these yarns.
Modern looms can be grouped into two classes according to whether they produce cloth in plane or
tubular form. Looms of the first kind, comprising all but a few, are called flat looms; the others are
described as circular. Since the majority are flat looms, the adjective is used only when a distinction
has to be drawn. Flat looms fall into two categories: those that employ a shuttle and those that draw
the weft from a stationary supply, usually called shuttleless looms. (This term is not entirely
satisfactory, as some primitive looms make no use of a shuttle, merely passing through the shed a
stick with weft wound on it.) Shuttle looms fall into two groups according to whether the shuttle is
replenished by hand or automatically. The second kind is often described as an automatic loom, but,
except for shuttle replenishment, it is no more automatic in its operation than the hand-replenished or
so-called nonautomatic loom, which, like all modern looms, is power-operated by electric motor.
With both types of loom the actual weaving operation is entirely automatic and is performed in exactly
the same manner.
Hand-replenished, or nonautomatic, looms are used only where particular circumstances—of yarns,
fabrics, or use—make automatically replenished looms either technically unsuitable or uneconomic.
Basically, they differ little from the power looms of the latter half of the 19th century. They do not
run appreciably faster but are better engineered, making use, for example, of machine-cut instead of
cast gear wheels. Often there is no superstructure, which makes for cleanliness and improved
illumination; frequently rigid heddle connectors are employed, leading to precise and stable setting
of the shed; and usually the overpick mechanism has been replaced by the cleaner and safer underpick.
Automatically replenished flat, or automatic, looms are the most important class of modern loom,
available for a very wide range of fabrics. In virtually all such looms, the shuttle is replenished by
automatically replacing the exhausted bobbin with a full one. In principle they are thus the same as
the automatic looms introduced at the end of the 19th century. Since that time, automatic shuttle-
changing looms have also been introduced but have largely become obsolete, because bobbin-
changing looms have been developed to a point where they can deal with most of the yarns for which
it was once thought necessary to use shuttle-changing looms.
Classification of Modern Loom:
Modern loom or shuttle less loom has classified into four types, those are-
1. Projectile loom,
2. Air jet loom,
3. Rapier loom,
4. Water Jet loom.

3. 1. Projectile Loom:
Projectile loom is a shuttle less loom. It is sometimes called missile loom as the picking action is done
by a series of small bullet like projectiles which hold the weft yarn and carry it through the shed and
then return empty. Projectile loom has a high speed production than the rapier loom.
The projectile weaving machine made its appearance in the market at the beginning of the 50’s and
is today still used in the whole world. Thanks to its steady renovation and to the use of advanced
electronic systems as well as of microprocessors for the supervision and the control of the various
devices, this machine is characterized by a good productivity level (450 rpm and 1050 m/min of
inserted weft) and by high operational reliability. It is established especially in the field of machines
with high reed width.
Fig: Projectile loom
General Operation:
In this weaving machine the weft insertion is carried out by small clamp projectiles, which number
depends on the weaving width and which with their grippers take out the weft yarn from big cross-
wound bobbins and insert it into the shed always in the same direction. The projectiles work in
sequence, that is they are launched in succession. They run therefore one after the other, describing
in the space a continuous, endless route, as if they would be stuck on a conveyor belt.
The first projectile takes and holds in its back the weft in form of a tail; then, pushed by the release
of the projectile thrower, it passes through the shed and deposits the weft inside the warp;
subsequently the projectile falls and is collected by a device which, by passing under the array of the
warp threads, takes it at reduced speed back to the starting point. Here the projectile goes up to take
up a new weft; meanwhile the other projectiles have run after each other making the same operation.
Projectile Guide:
The limited weight and the reduced volume of the projectile make a projectile guide necessary . The
projectiles therefore do not come into contact with the threads, but run inside a sort of channel
composed of the thin prongs of a rake, which form reminds a semiclosed hand. This rake goes up
from under the threads at the moment of the projectile launch and has of course to fall back lowering
itself at the slay stroke. To enable this movement, the rake is secured on the slay and is positioned
very close to the reed; the rake’s laminas are not in contact with the warp, or touch it very lightly
because the reed opens them the way. The latest models of the projectile machine have been equipped
with new types of guide dents, which are divided and placed in alternate position, in order to reduce
the stress on weft and warp threads. This permits to use in warp even very delicate yarns as for

4. instance untwisted or entangled yarns and at the same time to cope with high quality requirements.
Projectile Launching Mechanism:
The operational principle of the launching mechanism is the following a torsion bar 2 is anchored, at
one side, to the fixed point 1, whereas the free end is connected by a toothed groove to the percussion
shaft 3. The percussion lever 9, which is fixed to the percussion shaft 3, follows per force the
movements of this last and consequently of the free end of the torsion bar 2. During its rotation, the
cam 8 shifts the knee-joint lever 4+5, so that the torsion bar 2 is put under tension by the percussion
shaft 3 and the percussion lever 9 is put in launching position (the scheme shows the launching
mechanism with the torsion bar in the phase of maximum tension). The torsion bar 2 remains under
tension until the roller 7 slides along the bend of lever 5. The particular shape of this lever makes so
that the roller, when leaving it, presses its end, thus giving the starting point to the torsion bar for the
articulation of the knee-joint lever 4+5. Subsequently the torsion bar 2 returns suddenly to its rest
position imparting a strong acceleration to the projectile 11 through the percussion shaft 3 , the
percussion lever 9 and the percussion element 10. The oil brake 6 serves to damp the stroke.
Features Of Projectile Loom:
• Accommodator used reduce tension
• Power consumption is less (3 kw-hrs.)
• No.of projectile 11 to 17
• Width minimum 190 cm
• Width maximum 540 cm Multiple fabric produce
• Double beam single fabric can be produced in projectile
Advantages Of Projectile Loom:
• Fashionable fabric may produce
• Drawing-in pinning of drop wires and knotting are accepted prectice
• The west and warp stop motions actuate first and reliable
• Simple to operate and maintain
• Two or three cloths can be woven simultaneously.
• It is possible to achieve weaving performances with breakage rate per square meter of cloth.
50% of the number of breaks that would occur on a conventional loom
• Since the projectile is passing through guides there is no reed to projectile or projectile to yarn
contact.
Three Cases Are Possible:
1. Position I (normal projectile position): the control co-ordinates S of sensors 1 and 3 are covered
by the projectile;
2. Position II (projectile too far penetrated / insufficient braking): the control co-ordinate S of sensor
III is not covered;
3. Position III (projectile insufficiently penetrated / excessive braking): the control coordinate S of
sensor 3 is not covered.
2. Air Jet Loom:
The air jet weaving machine combines high performance with low manufacturing requirements. It
has an extremely high insertion rate. Due to its exceptional performance, air jet machines are used
primarily for the economical production of standard fabrics, covering a wide range of styles.
Meanwhile, more and more niches and special fabric segments are covered; heavy cotton fabrics such
as denim, terry fabrics, glass fabrics, etc

5. .Fig: Air Jet Loom
The Air Jet weaving machines are the weaving machines with the highest weft insertion performance
and are considered as the most productive in the manufacturing of light to medium weight fabrics,
preferably made of cotton and certain man-made fibers. These machines are the ideal solution for
those who want to produce bulk quantities of customized fabric styles. The weaving widths range
generally from 190 to 400 cm.
The air jet weaving machines are the weaving machines with the highest weft insertion performance
and are considered as the most productive in the manufacturing of light to medium weight fabrics,
preferably made of cotton and certain man-made fibres (sheets, shirting fabrics, linings, taffetas and
satins in staple yarns of man-made fibres); it has any way to be pointed out that technically positive
results are obtained at present also with heavyweight fabrics (denim) and that some manufacturers
produce also machine models for terry production.
These machines are the ideal solution for those who want to produce bulk quantities of customized
fabric styles. The weaving widths range generally from 190 to 400 cm. As regards the multicolor weft
carrier, up to 8 different wefts can be fed.
It has, however, to be considered that the air jet weaving machines require a high energy consumption
to prepare the compressed air and that this consumption rises definitely with increasing loom width
and running speed. The reduction in the energy consumption is, in fact, one of the main concerns of
the manufacturers and builds for the user an important selection criterion.
Features Of Air Jet Loom:
• Weft yarn insertion us done by air force.
• Finer count of yarn is used as the weft thread to produce fancy type of fabric.
• Air jet loom is high speed loom having good quality.
• For instance on a weaving machine having a speed of 600rpm the weaving cycle is 100m/s.
• Weft yarn insertion us done by air force.
• Cam Control valves have the advantages of hugh speed precision of action whilst the
electricity controlled selonoid valves permit easy setting.
Advantages Of Air Jet Loom:
• Higher production capacity.
• High quality and complex design fabric can produce
• Automatic pick repairing
• Heavier yarns are suitable for air jet looms

6. Disadvantages Of Air Jet Loom:
• Loose pick.
• Need too high nozzle pressure.
• Power consumption dew to compressed air
• Lighter fabrics are very difficult to control through shed
• Too heavy yarns also can't be carried across the loom by air jet
3. Rapier Loom:
Rapier loom is a shuttleless weaving loom in which the filling yarn is carried through the shed of
warp yarns to the other side of the loom by finger like carriers called rapiers. As in the projectile
loom, a stationary package of yarn is used to supply the weft yarns in the rapier machine. One end of
a rapier, a rod or steel tape, carries the weft yarn. The other end of the rapier is connected to the
control system .The rapier moves across the width of the fabric, carrying the weft yarn across through
the shed to the opposite side. The rapier is then retracted, leaving the new filling in place.
Fig: Rapier Loom
In some versions of the machine, two rapiers are used, each half the width of the fabric in size. One
rapier carries the yarn to the center of the shed, where the opposing rapier picks up the yarn and
carries it the remainder of the way across the shed. A disadvantage of both these techniques is the
space required for the machine if a rigid rapier is used. The housing for the rapiers must take up as
much space as the width of the machine. To overcome this problem, looms with flexible rapiers have
been devised. The flexible rapier can be coiled as it is withdrawn and will therefore require less space.
However, if the rapier is too stiff, it will not coil; if it is too flexible, it will buckle.
The double rapier is used more frequently than the single rapier. Rigid and flexible rapier machines
operate at speeds of up to 1,300 meters of weft per minute. These rapier looms are efficient. They
operate at speeds ranging from about 200 to 260 ppm at about the noise level of projectile looms.
They can produce a wide variety of fabrics ranging from muslin to drapery and upholstery materials.

7. Fig: The operation principle of three rapier systems
Newer rapier machines are built with two distinct weaving areas for two separate fabrics. On such
machines, one rapier picks up the yarn from the center, between the two fabrics, and carries it across
one weaving area; as it finishes laying that pick, the opposite end of the rapier picks up another yarn
from the center, and the rapier moves in the other direction to lay a pick for the second weaving area,
on the other half of the machine. The above figure shows the action on a single width of fabric for a
single rigid rapier system, a double rigid rapier system, and a double flexible rapier system.
Rapier machines weave more rapidly than most shuttle machines but more slowly than most projectile
machines. An important advantage of rapier machines is their flexibility, which perm it’s the laying
of picks of different colors. They also weave yarns of any type of fiber and can weave fabrics up to
110 inches in width without modification.
Features Of Rapier Loom:
• Fancy fabric produced
• Production costly
• Power consumption moderate
• Simple mechanism
• Suitable for weft patterning
• Standard rapier width 190 cm.
• Production speed 200-260 ppm
Picking Mechanism of Rapier Loom:
 The rapier head on creel side picks up yarn from designated cone and is carried towards centre
of warp shed by the rod.
 Simultaneously the matching rapier head from opposite side moves in, as shown in the central
diagram.
 The picking cycle is completed when both rapiers retreat to their original position.

8. Advantages Of Rapier Loom:
• The weft insertion rate in a rapier loom is very much influenced by the method of weft control.
• It can be occur double pick at a time by double picking insertion system. Here is no need to
cut the weft selvedge and no weft wastage.
• Weft insertion rate is very high rather than any conventional loom.
• Thee rapier loom doesn’t require dynamic forces or anything like the magnitude as those
involved in the conventional loom.
• Looms that use rigid rapiers eliminate entirely the need to assist the rapier head through the
warp shed, this is a undoubted advantages.
Disadvantages Of Rapier Loom:
• In case of rapier loom, noise level is higher than jet loom machine.
• Here, production speed is less than jet loom.
Scope Of Rapier Loom:
• Single rapier loom can insert weft only on alternate rapier traverse.
• Due to high rate of insertion the possiblility of yarn breakage rate may increase.
• In many case this is modified to achieve a higher rapier vrlocity in the early and late parts of
the movement and thus a over maximum velocity halfway through the movement.
4. Water Jet Loom:
Water Jet loom are extensively used in East Asia. They are characterized in particular by high
insertion performance and low energy consumption. These machines are produced only by few
companies and are used for the manufacture of light and medium weight fabrics with standard
characteristics and in water-repellent fiber materials, primarily multi-filament synthetic yarns. They
are characterized in particular by high insertion performance and low energy consumption.
These machines are produced only by few companies and are used for the manufacture of light and
medium weight fabrics with standard characteristics and in water-repellent fiber materials, primarily
multi-filament synthetic yarns.
Water jet machines are extensively used in East Asia, but have limited importance in other countries.
They are characterized in particular by high insertion performance and low energy consumption.

9. Structure of water jet loom
Operation Principle:
The figure shows how the machine operates. The weft yarn, which is fed from cone 7, is drawn-off
by a feeding and measuring device 2 and then passes through a tension regulator 3 and a weft clamp
4. When the insertion has to take place, the weft clamp loosens its hold and the thread inserted inside
a nozzle 1 is struck by a jet of pressurized water and launched through the shed at high speed.
After the insertion has taken place, while the weft is held flat by the threads which are moved by the
leno mechanisms 5, the thermal knives 14 enter into action on the launch side to cut the weft, and on
the opposite side to trim the fabric. A yarn clamping device 13 holds the weft waste which is cut off
by the right-handed thermal knife while rotating gears arrange for its removal (center selvedge).
Features Of Water Jet Loom:
• This type of loom is suitable for non absorbent fibre like synthetic fabric
• Less power consumption -
• Highest west insertion (600 ppm)
• Weft yarn package weight 3,6-4, 1 kg
• Treated water are used by pump nozzle
Advantages Of Water Jet Loom:
• Less power consumption
• Production rate is high
• Noise level is lower then missile and rapier loom
• This type of loom is suitable for non absorbent fibre like synthetic fibre
Disadvantages Of Water Jet Loom
• Not suitable for absorbent fibre like cotton
• By hard water may form rust on the yarn.

10.  Multiphase Loom:
The phase number of a loom is defined as the average number of shuttles or weft carriers inserting
weft simultaneously. It is shown that existing multi-phase loom must have high phase numbers to
compensate for their low shuttle velocity.
Fig: Muliphase Loom
Features Of Multiphase Loom:
• Continuous weft insertion occurs in multiphase loom.
• Required an ever-changing warp shed, which is sometimes called waveshedding.
• 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.
Advantages Of Multiphase Loom:
• An analysis of the factors determining the weft-insertion rate of weaving machines shows that
these factors are essentially the same on all looms.
• Its advantages include high efficiency, high speed and low weaving cost.
• The multiphase loom can form many different sheds at different places, thereby enabling
insertion of number of filling yarns, one behind The other .
Present Scenario of Modern Loom in Bangladesh:
There are various designs and structure oriented woven fabric are produced by this sector. Mainly
plain weave fabric is major production. This sector can produce only 40% of woven fabrics for woven
RMG. The situation of weaving sectors of Bangladesh are given below:
Weaving Mills:
• Looms -17,000 shuttle less and 13,000 shuttle
• Production capacity- 215 core meter
• Employment -80,000

11. Modern loom:
This sector is very popular sector of Bangladesh. Jamdani, and banarosi like luxurious share are
produced by this sector. The hand loom industry provides employment for a large segment of the
rural population of Bangladesh. It also helps in self employment of rural women.
Liton, M., Islam, T., and Saha, S. (2016) the study found that in Bangladesh there are about 183512
modernlooms weaving units with about 505556 looms. The total operational looms are 311851, which
are 61.7 percent of total looms, and the rest 193705 looms are non-operational.
• No. of units – 1,83,512
• Production capacity – 837 core mtr.
• No. of hand looms – 5.05 lakh
• Employment – 10.2 lakh (50% female)
• The industry also supplies a large portion of the fabric required by the local market.
• Bangladesh hand loom board looks after the sector.
Power Loom:
Mainly synthetic and specialized products are produced. Share, lungi, and gamcha also produced at
this sector. Local primary textile industry meets 90% of domestic fabric demand.
• No. of units – 1065
• Production capacity – 40 core meter
• Employment -43,000
Conclusion:
Nowadays in Bangladesh, uses of modern loom is increasing day by day. We know that the number
of weaving factories are increasing. And in those factories, they are using modern weaving machine
to get extra feature and advantage more than handloom or manual loom.
Modern loom is playing a vital role in our economical market. Modern loom increases production,
efficiency of production is increased because of using of modern loom. In our country modern loom
is like an evolution.
---The End—
Submitted by,
Md Rakibul Hassan
Id: 183014057
Reference-
1.https://www.slideshare.net/IbrahimIbrahim61/modern-
loom#:~:text=Its%20advantages%20include%20high%20efficiency,yarns%2C%20o
ne%20behind%20The%20other%20.
2.https://textilelearner.blogspot.com/2013/07/different-types-of-loom-
conventional.html
3. https://textilelearner.blogspot.com/2012/05/rapier-weaving-machine-rapier-
loom.html