2. TOPIC
* WEAVING
* WEAVING PROCESS
* PREPARATION OF WARPAND WEFT
* METHODS OF WEAVING
* HANDLOOMS AND POWERLOOMS AND THEIR
MERITS AND DEMERITS
PRESENTED BY :
Ms. KALPNA SUDAN
3. WEAVING
Weaving is the most basic process in which two
different sets of the yarns and threads are
interlaced with each other to form a fabric or cloth.
One of these sets is called warp which is the
length wise yarn running from the back to the front
of the loom. The other set of crosswise yarns are
the filling which is called the weft or the woof.
Silk weaving in India has always been of the
traditional type.
There are about 23 lakh apprx. handlooms and 9
lakh power looms exclusively for silk weaving.
Superior quality of yarn is used for warp
formation, while inferior grades are used for
weft.
4.
5. PREPARATIONFOR WEAVING
Yarn is the basic building block in weaving. However, in
practice, the condition of yarn produced on the spinning
machine is not always good enough to be used directly for
fabric formation.
Both filling yarn and warp yarn to be further processed
for efficient fabric formation. These preparatory processes
are called weaving preparation.
Warp and filling yarns are subjected to different
conditions and requirements during weaving. Therefore,
preparation of warp and filling yarns is different.
6. Warp yarn is subjected to higher stresses which
requires extra preparation.
The filling yarns are not subjected to the same type of
stresses as the warp yarns and thus are easily prepared
for the weaving process.
Winding is the major process and common for
both filling and warp preparation.
7.
8. WINDING
Winding is basically transferring a yarn from one type of
package to another.
Winding process
There are three main regions in winding:-
Region 1:- The region of unwinding of yarn from the
spinning package- the yarn package is held in the creel in
an optimum position for unwinding.
Region 2:- The tensioning and clearing region. In this
region , proper tension is given to the yarn for a desired
package density and body.
Region 3:-The unwinding region. In this region the yarn
package which is suitable for further processing is wound on
cone, tube or spool depending on the next stage of
processing.
9.
10. PREPARATIONOF WARP
• Preparation of warp is important because warp has to
undergoes various stresses like extension /contraction,
rotation while twisting/untwisting and abrasion with yarn
as well as metal .
• Also faster weaving speed and use of insertion device are
apart from shuttle have increased the necessity of warp
preparation before weaving.
• The preparation of warp is more demanding and
complicated than that of filling yarn.
• Each spot in a warp yarn must have uniform properties
with sufficient strength to withstand stress and friction
during weaving.
• The no. of knots should be kept to a minimum.
• Yarn on the warp sheet must be parallel to each other with
equal tension.
• Warp preparation involves winding, warping, slashing and
drawing in or tying in.
12. PREPARATIONOF WEFT
WEFT: The yarn that goes across width of a woven fabric.
• Weft yarn undergoes pirn winding or quill .
• Quil is bobbin on which filling is wound.
• The bobbin is placed inside the shuttle.
• The machine that are used to wind the quills are called
as quillers /pirn winding machine.
• This process of quill winding is gradually disappearing
with the advent of shuttle less loom.
13. PROCESS OF WEAVING
The five basic process that are essential for weaving are:
1) Warp let –off
2) Warp shedding
3) Filling insertion
4) Beat up
5) Fabrics take up
14. Warf let –off
The warp yarn release the warp beam as the warp is
woven into the fabric .The let off mechanism applies
tension to the warp yarn which control the crimps rates
of the warp and mechanism should keep the proper
tension on the warp yarn which control the crimps rates
of the warp and filling yarns. Let off mechanism can be
classified as mechanical or electronic. Most modern
weaving machine have electronic let –off. It provides a
positive and controlled release of warp yarn .It is good for
preventing fabric defect.
15. WARP SHEDDING
It is the movement of some warp yarn up
and some down to make an angle
opening for the filling to be inserted
through. This opening is called shed. The
warp sheet has to be re arranged
according to the fabric pattern. So that
the required fabric structure is produced.
17. FILLINGINSERTION
After each shed change, the filling yarn is
inserted through the shed. It is possible to
select and insert different filling yarn one
after another .Weaving machine is usually
classified according to the filling insertion
mechanism. The major filling insertion system
are used today are Air jet, Rapier projectile
and watered which are called shuttle less
machines.
19. BEAT UP
When the filling yarn is inserted through the shed, it lies
relatively far from its final position .This is because
insertion device cannot physically fit the angle of the
shed opening. Beat up is the process of pushing the
last inserted filling yarn to the cloth fell by using a
device called reed.
FABRICS TAKE UP: As the fabric is woven it should be
removed from the weaving area .This is achieved by
take up motion.
22. HAND LOOM
Silk weaving in India is totally traditional. It is carried
out a large extend on hand loom, power loom taking a
small portion of total production. These looms are
operated manually by the weaver. Shuttle is moved from
one end to another by hand and the weaver uses his feet
to operate the heralds’. There are 23 lakh silk hand
looms in India exclusively for weaving. The distinguish
feature of the primitive looms is that the weft is
threaded by hand and interlacing the warp ends. The pit
looms and frame looms can be classified into two main
groups looms with throw shuttle sley and loom with fly
shuttle sley.
23. Throwshuttle loom
The finest silk are woven on throw shuttle loom, pit
loom, in fact Indian legendary brocades of Banaras the
patola sarees of Gujarat and Himrus of South India are
the product of the throw shuttle looms.
Fly shuttle looms
The fly shuttle loom has mechanized weaving. The loom
raises production several times. The major difference
between the throw shuttle loom and fly shuttle loom is
that, the fly shuttle loom has a race board and the two
shuttle boxes catered by the sley on either side.
24. FRAME LOOM
The most delicate fabric in china and India have been
woven on an ancient horizontal frame loom with a
treadle. The modern horizontal frame scores over the fly
shuttle loom it is a complete unit with independently
fitted parts. It combines advantage of both throw shuttle
and fly shuttle loom.
SEMI AUTOMATIC LOOM
The hand loom run by an electric motor is
known as semi automatic loom, these loom yield three or
four times more than hand loom and has an output of
over half of the power loom. This loom can be operated
without electric power to manufacture plain fabrics. The
loom cost less than ordinary power loom.
25. MERITSOF HAND LOOMS
*At the beginning of the industrial revolution the first
major modern improvement was made on handloom 1733.
*The various merits of handloom are
*The handloom industry is essentially a cottage industry.
*Here the workers need basic skill of intelligence.
*Women and children also work along with men folk.
*The finest silk are woven on the throw shuttle pit loom
i.e. patola sarees of Gujarat.
*Handloom such as semi automatic loom can be operated
without power loom.
26. DEMERITS OF HANDLOOM
Although the handlooms have a number of advantages,
yet it has some disadvantages also:
*It requires all the basic skill of weaving for single person
to operate.
*It consumes more time and its production is low.
*It is labour intensive and if a person operate loom per 8
hour a day, he will produce only 4-5 meters of cloth.
*Because of all these demerits the weaver has to suffer a
lot because of low price.
27. POWER LOOM
Power loom are operated by power there by increasing
the production and reducing strain of the weaver .This is
why these loom are widely used. It is a mechanised loom
with rotary driving and accurate timed movements to
provide a high rate of speed and production. The frame is
of iron instead of wood .There are about 9 lakh power
loom in India exclusively for weaving. Modern power loom
can be divided into two categories according to whether
they produce cloth in plain or tubular form; the former
ones are known as flat loom and the latter as circular
loom.
28. FLAT LOOM
Shuttle less loom: It is the oldest types of weaving loom.
These looms were invented to improve weaving speed and
reduce noise pollution .In one of the modern loom shuttle
are not used for pressing in the weft . It uses the
mechanism of opening the warp up and down the
mechanism of pressing inserted weft with a yarn guide. In
this machine, the weft is cut at fixed length, is sent to the
end or beginning direction .many kind of shuttle less
looms are used for weaving such as projectile loom ,rapier
loom ,water jet loom ,air jet loom.
29. PROJECTILE LOOM: It is sometimes called as missile loom
as the picking action is done by series of bullet like
projectile which hold the weft yarn and carry it through the
shed and then return empty .All the filling yarn are
inserted from the same side of the loom. This loom needs
smooth, uniform yarn which is properly sized in order to
reduce friction .This loom can produce up to 300ppm.
30. Rapier loom: Rapier loom comes in many types .Early
models of it use one long rapier device that travel along
the width of the loom to carry the weft from one side to
the other . Another type of rapier loom has rapier , one on
each of the loom . They may be rigid and flexible. Rapier
looms are very efficient and their speed range from 200-
260ppm.These loom can manufacture a variety of fabrics
ranging from muslin fabric to drapery fabrics and even
upholstery fabrics.
31. Water jet loom: These looms are very fast with speed up to
660ppm and very low noise .Also they don’t place much
tension on the filling yarn very high quality of warp yarn are
needed for efficient operation. Also, only yarns that are not
readily absorbent can be used to make fabrics on water jet
loom such as filament yarn of nylon , polyester etc .However
it can produce very high quality fabrics having great
appearance and feel.
32. Air jet looms
These loom use a jet of air to proper filling yarn through the
shed at the speed of up to 600ppm. These looms require
uniform filling yarns and are more suitable for heavier yarn
because it is difficult to control lighter yarn. 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 .
33. Circular loom
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 materials .
34. MERITS OF POWERLOOM:
*The power came into existence since two decades, 1970.
The power looms have a number of merits over handloom
which are summarize.
*Power loom can easily satisfy the demand of time.
*The output on power loom is remarkable greater than the
rest of handloom.
*The speed of modern power looms is wonderful and thus
they are time saving.
*In power loom weaving, there is division of labour.
35. DEMERITS OF POWERLOOM
*As power loom are mostly preferred over hand loom yet
they have certain demerits which are as:
*Power loom can only be operated when there is power
supply.
* Power loom produce a lot of noise.
*Because of the division of labour, people have only
knowledge about his work, not about the whole process.
*Because of the mass production, the quality of modern silk
has decreased.
*In power loom , sometimes there may be occur breakage
of threads due to abrasion on warp yarn ,as a result of
which machine has to be stopped for tying the broken end.
36. Conclussion
As a conclusion weaving is a necessary process in
fabric manufacturing. It is essential because the final
product I.e. fabric is produced by this method.
Although India’s most famous legendary brocades i.e.
the ”patola” sarees of Gujarat and “himrus” of south
India are the product of weaving. But due to the
modern pressure of costs benefits and mass production
quality of silk has decreased.
