Twill is a type of textile weave with a pattern of diagonal parallel ribs (in contrast with

a satin and plain weave). This is done by passing theweft thread over one or more warp threads and then
under two or more warp threads and so on, with a "step" or offset between rows to create the characteristic
diagonal pattern.[1] Because of this structure, twills generally drape well.
Examples of twill fabric are denim, tweed, chino, gabardine, drill, covert, and serge.

A twill weave can be identified by its diagonal lines. This is a 2/2 twill, with
two warp threads crossing every two weft threads.
DENIM
Denim[1] is a sturdy cotton warp-faced[2] twill textile in which the weft passes under two or
more warp threads. This twill weaving produces the familiar diagonal ribbing of the denim that distinguishes
it from cotton duck.
It is a characteristic of most indigo denim that only the warp threads are dyed, whereas the weft threads
remain plain white. As a result of the warp-faced twill weaving, one side of the textile then shows the blue
warp threads and the other side shows the white weft threads. This is why blue jeans are white on the
inside. The indigo dyeing process, in which the core of the warp threads remains white, creates denim's
fading characteristics, which are unique compared to every other textile.

Cotton duck (from Dutch: doek, "linen canvas"), also simply duck, sometimes duck cloth or duck
canvas, is a heavy, plain woven cotton fabric. Duck canvas differs from plain canvas in that the threads in
the former are more tightly woven. There is also linen duck, which is less often used.
Duck is used in a wide range of applications, from sneakers to use for artists' paintings
to tents to sandbags.[1]
Duck fabric is woven with two yarns together in the warp and a single yarn in the weft.

Rapier 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 pick in place. In some versions of the loom, two rapiers
are used, each half the width of the fabric in size. One rapier carries the yarn to the centre of the shed,
where the opposing rapier picks up the yarn and carries it the remainder of the way across the shed. [1] The
double rapier is used more frequently than the single rapier due to its increased pick insertion speed and
ability to weave wider widths of fabric. 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, therefore requiring less storage space. If, however, the rapier is too
stiff then it will not coil; If it is too flexible, it will buckle. Rigid and flexible rapier machines operate at speeds
operating at speeds ranging from about 200 to 260 ppm, using up to 1300 meters of weft yarn every
minute. They have a noise level similar to that of modern projectile looms. They can produce a wide variety
of fabrics ranging from muslin to drapery and upholstery materials.
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 other
projectile machines. An important advantage of rapier machines is their flexibility, which permits 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.

Dobby is a woven fabric produced on the dobby loom, characterised by small geometric patterns and extra
texture in the cloth.[1] The warp and weft threads may be the same colour or different. Satin threads are
particularly effective in this kind of weave as their texture will highlight the pattern.[2]
Polo shirts are usually made with dobby.[1] piqu fabrics are a type of dobby construction.

A Dobby loom is a type of floor loom that controls all the warp threads using a device called a dobby.
(The word dobby is a corruption of "draw boy" which refers to the weaver's helpers who used to control the
warp thread by pulling on draw threads.) A dobby loom is an alternative to a treadle loom. Both are floor
looms in which every warp thread on the loom is attached to a single shaft using a device called a heddle.
A shaft is sometimes known as a harness. Each shaft controls a set of threads. Raising or lowering several
shafts at the same time gives a huge variety of possible sheds (gaps) through which the shuttle containing
the weft thread can be thrown.

The Jacquard loom is a mechanical loom, invented by Joseph Marie Jacquard, first demonstrated in 1801,
that simplifies the process of manufacturing textiles with such complex patterns
as brocade, damask and matelasse.[3][4] The loom was controlled by a "chain of cards", a number
of punched cards, laced together into a continuous sequence.[5] Multiple rows of holes were punched on
each card, with one complete card corresponding to one row of the design. Several such paper cards,
generally white in color, can be seen in the images below. Chains, like the much later paper tape, allowed

sequences of any length to be constructed, not limited by the size of a card.

Canvas is an extremely heavy-duty plain-woven fabric used for making sails, tents, marquees, backpacks,
and other items for which sturdiness is required. It is also popularly used by artists as a painting surface,
typically stretched across a wooden frame. It is also used in such fashion objects as handbags, electronic
device cases and shoes.
Modern canvas is usually made of cotton or linen, although historically it was made from hemp. It differs
from other heavy cotton fabrics, such as denim, in being plain weave rather than twill weave. Canvas
comes in two basic types: plain and duck. The threads in duck canvas are more tightly woven. The
term duck comes from the Dutch word for cloth, doek. In the United States, canvas is classified in two
ways: by weight (ounces per square yard) and by a graded number system. The numbers run in reverse of
the weight so a number 10 canvas is lighter than number 4.

Do you need to know the EPI and PPI of woven fabrics at the time of fabric
sourcing? And want to be ensured yourself that you have received right fabric in
terms of fabric construction. You can do that just by siting on your chair.
For newbie, EPI stands for Ends per inch and PPI stands for Picks per inch. Where
Ends is known as Warps and Pick are known as weft yarn.
Being an merchant and sourcing professional, if you dont know how to find EPI
and PPI yourself you may need to send fabric sample to testing lab. In case,
factory has its in-house testing lab then it is ok. You would get the information of
fabric sample EPI and PPI on the same day. But when you need to send sample to
outside lab, it would cost you money and has to wait for at least one day.
There is a very simple method to find fabric EPI and PPI without any special
testing instruments. If you want to know how to find that continue reading.
There is one difficult thing to know exactly what are the warp and wefts in fabric.
Use our guide to identify warp and weft in a woven fabric. In most fabrics EPI is
higher than PPI.

Step 1: Collect fabric swatch

Collect fabric swatch for which you are going to find EPI and PPI. Lay fabric
sample on a flat table and remove all creases by hand press. Mark arrows for
warp and weft direction if you know.
Step 2: Make a square of one sq.inch on the sample
Mark a square of 1 X 1 inches on the fabric using pen or pencil. Try to marks lines
parallel to warp and weft direction. Cut 5 squares from different place of the
sample to calculate average EPI and PPI.

Step 3: Count number of ends and Picks inside those squares.

In case yarns are thicker and visible with open eyes count numbers of Ends and
picks using a needle or a pin. In case, yarns in the fabrics are not visible and not
possible to count with open eyes, pull out warp and weft yarns one by one from
the cut squares. Count numbers of yarns you get form one inch length and width
of fabric.
Using same method, find EPI and PPI from all 5 samples and calculate average
EPI and PPI.

Example:

Fabric sample

I have shown you an example of loosely woven fabric in the right side image. On
that fabric sample, a 1 X 1 square is made. The vertical laid yarns are ends
(warp) and horizontal yarns are picks (wefts). Here you can counts ends and
picks without any pick glass as the sample fabric is loosely woven. In one inch
length there is 9 ends and 8 picks.
So EPI and PPI of this sample is 9 and 8 respectively.

Weaving
Weaving is done by intersecting the longitudinal threads, the warp, i.e. "that which is thrown across", with
the transverse threads, the weft, i.e. "that which is woven".
The major components of the loom are the warp beam, heddles, harnesses or shafts (as few as two, four is
common, sixteen not unheard of), shuttle, reed and takeup roll. In the loom, yarn processing includes
shedding, picking, battening and taking-up operations. These are the principal motions.

Shedding. Shedding is the raising of part of the warp yarn to form a shed (the vertical space
between the raised and unraised warp yarns), through which the filling yarn, carried by the shuttle, can
be inserted. On the modern loom, simple and intricate shedding operations are performed
automatically by the heddle or heald frame, also known as a harness. This is a rectangular frame to
which a series of wires, called heddles or healds, are attached. The yarns are passed through the eye
holes of the heddles, which hang vertically from the harnesses. The weave pattern determines which
harness controls which warp yarns, and the number of harnesses used depends on the complexity of
the weave. Two common methods of controlling the heddles are dobbies and a Jacquard Head.

Shuttles

Picking. As the harnesses raise the heddles or healds, which raise the warp yarns, the shed is
created. The filling yarn is inserted through the shed by a small carrier device called a shuttle. The
shuttle is normally pointed at each end to allow passage through the shed. In a traditional shuttle loom,
the filling yarn is wound onto a quill, which in turn is mounted in the shuttle. The filling yarn emerges
through a hole in the shuttle as it moves across the loom. A single crossing of the shuttle from one side
of the loom to the other is known as a pick. As the shuttle moves back and forth across the shed, it
weaves an edge, or selvage, on each side of the fabric to prevent the fabric from raveling.

Battening. Between the heddles and the takeup roll, the warp threads pass through another frame
called the reed (which resembles a comb). The portion of the fabric that has already been formed but
not yet rolled up on the takeup roll is called the fell. After the shuttle moves across the loom laying
down the fill yarn, the weaver uses the reed to press (or batten) each filling yarn against the fell.
Conventional shuttle looms can operate at speeds of about 150 to 160 picks per minute. [2]

There are two secondary motions, because with each weaving operation the newly constructed fabric must
be wound on a cloth beam. This process is called taking up. At the same time, the warp yarns must be let
off or released from the warp beams. To become fully automatic, a loom needs a tertiary motion, the filling
stop motion. This will brake the loom, if the weft thread breaks. [2] An automatic loom requires 0.125 hp to
0.5 hp to operate.

Power looms[edit]
Main article: Power loom

Two Lancashire looms in the Queen Street Mill weaving shed, Burnley

A 1939 loom working at the Mueller Cloth Mill museum in Euskirchen, Germany.

Edmund Cartwright built and patented a power loom in 1785, and it was this that was adopted by the
nascent cotton industry in England. The silk loom made by Jacques Vaucanson in 1745 operated on the
same principles but wasn't developed further. The invention of the flying shuttle by John Kay was critical to
the development of a commercially successful power loom.[7] Cartwright's loom was impractical but the
ideas behind it were developed by numerous inventors in the Manchester area of England; whereby 1818
there were 32 factories containing 5732 looms.[8]
Horrocks loom was viable, but it was the Roberts Loom in 1830 that marked the turning point.
[9]

Incremental changes to the three motions continued to be made. The problems of sizing, stop-motions,

consistent take-up, and a temple to maintain the width remained. In 1841, Kenworthy
and Bullough produced the Lancashire Loom[10] which was self-acting or semi-automatic. This enables a
youngster to run six looms at the same time. Thus, for simple calicos, the power loom became more
economical to run than the hand loom- with complex patterning that used a dobby or Jacquard head, jobs
were still put out to handloom weavers until the 1870s. Incremental changes were made such as
the Dickinson Loom, culminating in the Keighley-born inventor Northrop, who was working for the Draper
Corporation inHopedale producing the fully automatic Northrop Loom. This loom recharged the shuttle
when the pirn was empty. The Draper E and X models became the leading products from 1909. They were
challenged by synthetic fibres such as rayon.[11]
From 1942 the faster and more efficient shuttleless Sulzer looms and the rapier looms were introduced.
[12]

Modern industrial looms can weave at 2000 weft insertions per minute.[13]

Weft insertion[edit]

A Picanol rapier loom

Different types of looms are most often defined by the way that the weft, or pick, is inserted into the warp.
Many advances in weft insertion have been made in order to make manufactured cloth more cost effective.
There are five main types of weft insertion and they are as follows:

Shuttle: The first ever powered looms were shuttle type looms. Spools of weft are unraveled as the
shuttle travels across the shed. This is very similar to projectile methods of weaving with the exception
that the weft spool is stored on the shuttle. These looms are considered obsolete in modern industrial
fabric manufacturing because these machines can only reach a maximum of 300 picks per minute.

Air Jet: An air jet loom uses short quick bursts of compressed air to propel the weft through the
shed in order to complete the weave. Air jets are the fastest traditional method of weaving in modern
manufacturing and they are able to achieve up to 1200 picks per minutes. However, the amounts of
compressed air required to run these looms as well as the complexity in the way the air jets are
positioned makes them more costly than other looms.

Water Jet: Water jet type looms use the same principle as air jet looms, however, they take
advantage of pressurized water to propel the weft. The advantage of this type of weaving is that water
power is cheaper where water is directly available on site. Picks per minute can reach as high as 1000.

Rapier loom: This type of weaving is very versatile in that rapier looms can weave using a large
variety of threads. There are several types of rapiers, however they all use a hook system attached to
a rod or metal band to pass the pick across the shed. These machines regularly reach 700 picks per
minute in normal production.

Projectile: Projectile looms utilize an object that is propelled across the shed, usually by spring
power, and is guided across the width of the cloth by a series of reeds. The projectile is then removed
from the weft fibre and it is returned to the opposite side of the machine so it can get reused. Multiple
projectiles are in use in order to increase the pick speed. Speeds max out on these machines at 1050
ppm.

Shedding[edit]
Dobby looms[edit]
A dobby loom is a type of floor loom that controls the whole warp threads using a dobby head. Dobby is a
corruption of "draw boy" which refers to the weaver's helpers who used to control the warp thread by pulling
on draw threads. A dobby loom is an alternative to a treadle loom, where multiple heddles (shafts) were
controlled by foot treadles- one for each heddle.
Jacquard looms[edit]
The Jacquard loom is a mechanical loom, invented by Joseph Marie Jacquard in 1801, that simplifies the
process of manufacturing textiles with complex patterns such asbrocade, damask and matelasse.[14][15] The
loom is controlled by punched cards with punched holes, each row of which corresponds to one row of the
design. Multiple rows of holes are punched on each card and the many cards that compose the design of
the textile are strung together in order. It is based on earlier inventions by the Frenchmen Basile
Bouchon (1725), Jean Baptiste Falcon (1728) and Jacques Vaucanson (1740)[16] To call it a loom is a
misnomer, a Jacquard head could be attached to a power loom or a hand loom, the head controlled which
warp thread was raised during shedding. Multiple shuttles could be used to control the colour of the weft
during picking.

Loom:
An apparatus for making fabric by weaving yarn or thread. A loom is a device used to weave
cloth. The basic purpose of any loom is to hold the warp threads under tension to facilitate
the interweaving of the weft threads. The precise shape of the loom and its mechanics may
vary, but the basic function is the same.

Loom

Shuttle Loom:
The shuttle loom is the oldest type of weaving loom which uses a shuttle which contains a
bobbin of filling yarn that appears through a hole situated in the side. The shuttle is batted
across the loom and during this process, it leaves a trail of the filling at the rate of about 110
to 225 picks per minute (ppm). Although very effective and versatile, the shuttle looms are
slow and noisy. Also the shuttle sometimes leads to abrasion on the warp yarns and at other
times causes thread breaks. As a result the machine has to be stopped for tying the broken
yarns.

Classification
Shuttle less loom:

of

Modern

Loom:

Many kinds of shuttle less looms are used for weaving such as Projectile Looms; Rapier
Looms;
Water
Jet
Looms;
and
Air
Jet
Looms.

Projectile 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.
All the filling yarns are inserted from the same side of the loom. A special tucking device
holds the ends of the wefts in place at the edge of the cloth to form the selvage. This loom

needs smooth, uniform yarn which is properly sized in order to reduce friction. Projectile
loom can produce up to 300 ppm and is less noisier then the shuttle loom.

Rapier Loom:
Rapier loom comes in many types. Early models of it use one long rapier device that travels
along the width of the loom to carry the weft from one side to the other. Another type of
rapier loom has two rapiers, one on each side of the loom. They may be rigid, flexible or
telescopic. One rapier feeds the weft halfway through the sheds of warp yarns to the arm on
the other side, which reaches in and carries it across the rest of the way. Rapier looms are
very efficient and their speed ranges from 200 to 260 ppm. These looms can manufacture a
variety of fabrics ranging from muslin fabric to drapery fabrics and even upholstery fabrics.

Water Jet Loom:

In it, a pre measured length of weft yarn is carried across the loom by a jet of water. These
looms are very fast with speeds up to 600 ppm and very low noise. Also they don't place
much tension on the filling yarn. As the pick is tension less, very high quality of warp yarns
are needed for efficient operation. Also, only yarns that are not readily absorbent can be
used to make fabrics on water jet looms such as filament yarn of acetate, nylon, polyester,
and glass. However, it can produce very high quality fabrics having great appearance and
feel.

Air Jet Looms:

In the air jet weaving looms, a jet of air is used to propel the weft yarn through the shed at
speeds of up to 600 ppm. Uniform weft yarns are needed to make fabrics on this loom. Also
heavier yarns are suitable for air jet looms as the lighter fabrics are very difficult to control
through shed. However, too heavy yarns also can't be carried across the loom by air jet. In
spite of these limitations, air jet loom can produce a wide variety of fabrics.

Circular Looms:
These looms are particularly used for making tubular fabrics rather than flat fabrics. A shuttle
device in it circulates the weft in a shed formed around the machine. A circular loom is
primarily used for bagging material.

Read more: http://textilelearner.blogspot.com/2011/08/what-is-loom-define-loom-shuttleloom_6904.html#ixzz3UdHP8nmv