Dr.

Muhammad Waqas Iqbal

Assistant Professor
Department of Yarn Manufacturing
National Textile University, Pakistan
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 Course

TE -1111
Introduction to Textile Engineering

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Fabric Manufacturing

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 Types of Fabric Manufacturing

• Weaving

• Knitting

• Bonding

• Felting or tufting

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 Weaving

• The process of producing a fabric by interlacing

warp and weft yarns is known as weaving. The
machine used for interlacement of yarns is
known as loom or weaving machine .

• In practice, the weaving machines are named

after their filling insertion systems (Shuttle or
shuttleless)

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 History of Weaving

Weaving is an art that has been practiced for thousands of years. The earliest application of
weaving dates back to the Egyptian civilization some 6000 years ago. Over the years, both the
process and the machine has undergone through changes. As of today, there is a wide range
of looms being used, right from the simplest hand loom to the most sophisticated loom.

The existing shuttle looms have been replaced by the shuttleless weaving machines in
industrialized countries. Nevertheless, approximately 2.6 million of the 3.2 million looms in
existence throughout the world in 1998 were still shuttle looms . However, they are being
replaced by the shuttleless weaving machines at a fast rate. Today, the three most popular
weaving machines are projectile, rapier and air-jet machines.
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Weaving Flow Chart

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 Weaving preparatory processes

• Winding

• Warping

• Sizing

• Drawing-in/Knotting

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 Winding

Winding is a process in which yarn from bobbins, which is the end product

of ring spinning, are converted into suitable form of package. This transfer

of yarn from one type of package to another package, more suitable for

the subsequent process is also called winding. Main objectives of winding

process are to increase the package size, clear yarn defects and produce a

package suitable for subsequent process (size and shape).

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 Warping

In warping process, the yarns are transferred from a number of supply packages
(cones) to the warp beam in the form of a sheet. The main objective of warping is to
get the required number of ends as per requirement.

The three main types of warping are high speed / direct warping, sectional / indirect
warping and ball warping. In direct warping, the yarns are withdrawn from the
single-end yarn packages (cone) on the creel and directly wound on a beam. The
indirect / sectional warping process completes in two steps, i. e. warping and
beaming. Ball warping is the process in which warping is performed in rope form on
to wooden ball.
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Direct Warping

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Sectional Warping

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Ball Warping

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 Sizing or Slashing
• The weaving process requires the warp yarn to be strong, smooth and elastic or
extensible to a certain degree. To achieve these properties on warp yarns, a
protective coating of polymeric film forming agent (size) is applied on the warp yarns
prior to weaving; this process is called slashing or sizing.

• The Purposes of sizing :

oTo reduce the yarn hairiness that would interfere with the weaving process
oTo protect the yarn from yarn-to-yarn and yarn-to-loom abrasion
oTo increase the strength of the yarn.
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Sizing Process

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 Drawing-in
After sizing, the sized warp beam is prepared to be placed on the weaving machine and
for this purpose drawing-in is done. It is the entering of yarns from a new warp beam
into the weaving elements of a machine, namely drop wires, heddles (healed wire) and
reed, when starting up a new fabric style.
Healed Wire
Drop Wire Reed

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Drawing-in

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Drawing-in

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 Weaving Principles
WARP:
• The length wise yarns which run from the back to the front of
the loom, which forms the basic structure of the fabric and are
called the warp. Warp yarns are yarns that are parallel to the
selvedge which run through the length of the fabric

WEFT/Fill:
• Crosswise yarns that run across the loom are called the weft /
filling yarns. Weft yarns are yarns that are perpendicular to the
selvedge which run through the width of the fabric

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Warp through a loom

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Weaving mechanism

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 Basic Operations of Weaving

The conversion of warp sheet into fabric by interlacing with weft yarn

requires the basic operations to be carried out on loom in a specific order.

It involves the primary motions, secondary motions and the stop motions

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 Primary motions

Shedding: the separation of the warp sheet into two layers to

form a tunnel known as the shed

Picking: insertion of weft yarn, across the warp sheet width,

through the shed

Beat-up: pushing the newly inserted length of weft (pick) to the

fell of cloth.

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 Secondary motions

The secondary motions facilitate the weaving of fabric in a continuous way.

These include:

Let off: this motion provides warp sheet to the weaving area at the required
rate and under constant tension by unwinding it from weaver’s beam

Take-up: this motion draws fabric from the weaving area at a uniform rate to
produce the required pick spacing and wind it onto a roller.

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 Stop motions

These motions are used in the interest of quality and productivity; stopping the loom
immediately in case of some problem.

 The warp stop motion will stop the loom in case any warp yarn breaks, avoiding
excessive damage to the warp threads.

 Similarly weft stop motion will come into action in the absence of weft yarn, and
stop the loom.

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 Weaving mechanisms/types of picking

Weaving machines are classified according to their filling insertion mechanism.

The classification is as follows:
1. Shuttle
2. Shuttle-less
· Projectile
· Rapier
· Air-Jet
· Water-Jet

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Weft insertion mechanisms

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Hand Loom

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Power Loom

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Projectile Loom

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Rapier Loom

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Air Jet Loom

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Air Jet mechanism

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Water Jet loom

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 Shuttle Picking

In shuttle weaving, a shuttle that traverses back

and forth across the loom width, inserts the

filling. Shuttles can be made of wood or plastic.

Filling yarn is wound on the quill and the quill is

placed in the shuttle. As the shuttle move across

the loom, the filling yarn is unwound from the

pirn and lay in the shed. A striking bar at both

ends cause the shuttle to move across the shed.

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Projectile Picking

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 Projectile Picking
Introduced first time by Sulzer in 1952. The machine use a small metallic
projectile along with a gripper to throw the weft yarn across the loom
width.
• The picking action is accomplished by a small bullet like gripper which
grips the weft yarn and carries it through the shed in a rake- shaped
guide. the Projectile is then conveyed to its original position by a
transport device installed under the shed.
• This is a more positive way of inserting the weft yarn without restoring
to the heavy shuttle.
• Because the mass of gripper is low, the forces needed to accelerate it are
less and the picking mechanism can be lighter.
• In addition, the running speed of the looms can be increased significantly
compared with conventional shuttle loom. Small bullet like gripper is
passed from one side to the other inside the shed
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 Rapier Picking

A rapier loom uses a rapier to pull the weft yarn across the loom.
It can be a single rapier or double rapier.
• For a single rapier, a long rapier device is required to extend across the
full width of warp.
• For a double rapier loom, two rapiers enter the shed from opposite sides
of the loom and transfer the weft from one rapier head to the other near
the center of the loom The advantage of two rapier system is only 50% of
the rapier movement is utilized in the weft insertion of single rapier loom

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 Air jet Picking

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.
• Technically positive results are obtained at present also with heavy weight
fabrics (denims) and that some manufacturers produce also machine models for
terry production. The weaving widths range generally from 190 to 400 cm.
• Multiple air nozzles are used to insert the weft yarn into the shed.
• With the air-jet looms, the initial propulsion force is provided by a main nozzle.
• The fabric width of air-jet loom is normally narrower than rapier or projectile
loom
• Products:-sheets, shirting fabrics, linings, and satins in staple yarns of man-
made fibers

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Air jet Picking

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 Air jet Picking

• Jet looms are faster than projectile or rapier looms (picks per minute).
However, they cannot produce as great a variety of fabrics (no heavy or
bulky yarns), nor can they produce as a wide a fabric (jets have less yarn-
carrying power).
• Jet looms also do less damage to the warp since there is no abrasion of
this yarn by the jets of air or water, unlike the projectile or rapier.
• 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.
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 Water jet Picking

• Water jet (I)

• With water jet looms, there is only a main nozzle to provided the propulsion of the
weft yarn. The loom is very efficient, with only a small amount of water required and
is the fastest type of shuttleless loom. Water-jet looms are capable of producing 700
picks per min (ppm) for 75-inch fabrics compared to about 180 picks per min for
shuttle looms with 44-inch fabric.
• Water jet (II)
• Since wet fabric cannot be stored in a roll, water jet looms are equipped
with efficient drying units. The units use vacuum suction and heat to remove the water
from the fabric. Water-jet looms are best suited for weaving filament yarns made of
hydrophobic fibres (water-resistance fiber) like nylon, or polyester/cotton. Yarns made
of fibres that lose strength when wet (e.g., rayon) should not be used.

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Water jet Picking

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Ending Notes

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