Loom
A loom is a device that is used to weave cloth and tapestry by the interlacement
of warp and weft threads. The main objects of any kind of loom are to hold the
warp threads in a correct tension to facilitate the interweaving of the weft
threads. The shape of the loom and its mechanics may different, but the basic
function is the same.
The main mechanism of the loom
The main mechanism of loom
includes shedding, picking, battening, and taking up.
i. Shedding
Shedding
is the lifting of the part of the warp yarn to form the shed, through which the
filling yarn carried by shuttle can be inserted and weft. In present looms,
easier and more complex shading operations are accomplished spontaneously by
heddle or heald frames is called a harness. It is a rectangular frame with a
series of wires attached to it called heddles or healds. The threads go through
the eye holes of the heddles, which hang vertically from the harnesses. The
weave pattern decides that harness controls that warp, and the number of
harnesses applies depends upon the difficulty of the weave. The two most common
methods of controlling handles are a dobby and a jacquard head.
ii. Picking
Harnesses
can raise the handles or healds that increase the warp yarn, creating sheds.
The filling thread is inserted through the shed with a small carrier device
called a shuttle. The shuttle is usually directed at each end to pass through
the shed. In a traditional shuttle loom, the filling thread is hit on a quill,
which in turn is mounted on the shuttle. As soon as the loom is passed, the
filling thread comes out through a hole in the shuttle. The single crossing of
the shuttle from one side of the loom to the other is called picking. As the
shuttle runs back and forth past the shed and it weaves an edge or selvage on
each side of the fabric to prevent the fabric from pulling.
iii. Beating
The
warp threads between the heddles and the takeup roll go through another frame
called the reed. The part of the fabric which has already been made but has not yet
rolled into the takeup roll is called the fell. After the shuttle has passed
the loom by placing the fill yarn underneath, the weaver uses the stick to
press each filled yarn against the fell. Conventional shuttle looms can operate at speeds of around 150 to 160 picks per minute.
Types of loom
There
are different types of looms we found. Such as below-
A. Based on power
There
are many types of loom based on power, such as below-
i. Backstrap loom
The backstrap loom is a simple loom with roots in ancient civilization. Even today,
Andes textiles made with the help of a backstrap loom originated thousands of
years ago with the same backstrap loom process. It consists of two sticks or
bars between which the warps extend. One bar is attached to a stationary object
and the other to a weaver, usually through a strap around the back. The weaver
leans back and uses his body weight to tighten the loom. Both simple and
complex textiles can be woven into this loom. The width is limited in how far the
loom can go from side to side to pass the shuttle. Warp-faced textiles are
often woven by indigenous peoples around the world today, adorned with
intricate pick-up patterns woven into supplementary and complementary warp
techniques. They produce things like belts, punches, bags, hatbands, and
clothes. Today, backstrap loom kits economically produced often include a rigid
heddle.
ii. Warp-weighted loom
The warp-weight loom is a vertical loom that may have originated in the Neolithic
era. This loom was used in ancient Greece and then spread throughout the north
and west. Its defining feature is the hanging of weights that tighten the
bundles of warp threads. Often the excess warp thread is wound around the
weight. When a weaver reaches the bottom of the available warp, the finished
part can be rotated around the top beam and additional magnetic threads from
the continued weight may be unwound. This frees the loom from the vertical size
limitation.
iii. Drawloom
A drawloom is a hand-loom that is used in weaving fabrics by drawing. In a
drawloom, a figure harness is used to control each warp thread individually. A
drawloom requires two operators such as a weaver and an assistant to manage the
figure harness. The earliest confirmed drawloom cloth comes from the Chu
kingdom and dates back to 400 BC. Most scholars have attributed the
discovery of this drawloom to the ancient Chinese and some have speculated that
there is an independent invention from Syria since the drawloom fabric found in
Dura-Europe dates back to 25 BC. Draw looms for patterned weaving were invented
in ancient China during the Han Dynasty. The Chinese-invented drawloom
increases and accelerates silk production and plays an important role in
Chinese silk weaving. The loom was later introduced in Persia, India, and
Europe.
iv. Handloom
A handloom is a common machine used for weaving. In a wooden vertical-shaft loom,
the heddles are fixed in place of the shaft. The warp threads periodically pass
through a heddle and through the space between the heddles, so that half the
thread is raised by raising the shaft, and lowering the shaft reduces the same
thread. It was a great discovery in the thirteenth century. In some cases,
shading is performed by foot operation. On the other hand, hand weaving is a
machine or device that is made from parts of wood and iron and used to produce
woven fabrics.
v. Power loom
Edmund Cartwright created and patented a power loom
in 1785, and it was he who took over England's renowned cotton industry. The
invention of the flying shuttle by John Kay was important for the development
of commercially successful power looms. Continuing to make incremental changes
at three speeds. In 1841, Kenworthy and Bullough made Lancashire looms that
were self-acting or semi-automatic. It enables a young man to run six looms
simultaneously. Thus, in the ordinary calico, the power loom becomes more
economical to run than the handloom and it uses a dobby or jacquard head with
complex patterning. Augmentative changes were made, such as the Dickinson loom,
ending with Keighley-born inventor Northrop, who was working on the production
of a fully automated Northrop loom on behalf of
Hopedale Dropper Corporation. By 1942, faster, more efficient, and shutterless
Sulzer and rapier looms were introduced. Modern industrial looms can weave at
2,000 weft inserts per minute.
B. Based on weft insertion
There are different types of looms that are found
based on weft insertion into the warp. There are five main types of weft
insertion as follows-
i. Shuttle loom
The first looms operated were shuttle looms. Weft's
spools have been blocked as the shuttle travels across the shed. This is very
similar to the weaving projection methods, except that the weft spool is stored
in the shuttle. These looms are considered obsolete in modern industrial fabric
production due to they can reach a maximum of 300 picks per minute.
ii. Rapier loom
This type of weaving is very common, with rapier
looms weaving using a variety of threads. There are different kinds of rapiers
loom we found, but they all use a hook system attached to a rod or metal band
for picking across the shed. This machine regularly reaches 700 picks per
minute in normal production.
ii. Water jet loom
The water-jet looms use the same principles as
air-jet looms but they operate the weft with the help of pressurized water. The
advantage of this type of weaving is that water power is cheap where water is
available directly on the site. Picks can reach a maximum of 1000 per minute.
iv. Projectile loom
Projectile looms use an object that is driven across
the shed, normally by spring force and by a chain across the width of the
fabric. The projectile is removed from the weft and it turns on the opposite
side of the machine wherein it may be reused. Multiple projectiles are used to
speed up sorting. The maximum speed on these machines can be more than 1,050
picks per minute.
v. Air jet loom
The air-jet loom uses short quick blasts of short
wind to drive the weft through the shed to complete the weaving. Air jets are
the fastest process of weaving in modern production and they are able to
achieve 1,500 picks per minute. However,
the amount of compressed air required to operate these looms, as well as the way
in which the air jets are located, and the disadvantages make them more
expensive than other looms.
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