The main mechanism of loom | Types of loom based on power and weft insertion

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.

Loom

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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