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A loom is a machine or device for weaving thread or yarn into textiles. Looms can range from very small hand-held frames, to large free-standing hand looms, to huge automatic mechanical looms. Every loom, whatever its size, performs the same essential service: it holds the warp threads stretched in order under tension, opens a shed between them for the weft to pass through, and presses each new weft thread into place against the woven cloth.
A loom is a machine or device for weaving thread or yarn into textiles. Looms can range from very small hand-held frames, to large free-standing hand looms, to huge automatic mechanical devices.
In practice, the basic purpose of any loom is to hold the warp theads under tension to facilitate the interweaving of the weft threads. The precise shape of the loom and its mechanics various, but the basic function is the same.
Weaving
See Weaving for more information.
Weaving is done by intersecting the longitudinal threads, the warp, i.e. "that which is thrown across" (Old English wearp, from weorpan, to throw, cf. German werfen) with the transverse threads, the woof or weft, i.e. "that which is woven" (Old English wefta, from wefan, to weave, cf. German weben).
The Old English geloma and Middle English lome meant an implement or tool of any kind.
The earliest example with its specific meaning quoted by the Oxford English Dictionary is from the Nottingham Records of 1404, but handwoven cloth existed much earlier, perhaps as far back as 8000 B.C.
Types of looms
Warp-weighted
The earliest looms were probably vertical warp-weighted looms, with the warp threads suspended from a branch or piece of wood and weighted or attached to the ground. The weft threads would be pushed into place by hand or a stick that would eventually become the shuttle. At first, it was necessary to raise and lower every warp thread one at a time, which was a time-consuming and laborious process. Basic techniques, such as the insertion of a rod, were developed to produce a shed, the space between warp threads (perhaps every other thread would be alternately raised and lowered), so that the weft thread or shuttle could pass through the entire warp at once.
Ground looms
On a horizontal ground loom, the warp would be strung between two rows of pegs. The weaver would have to lean over in order to work, so pit looms were developed, with the warp strung over a pit, so the weaver could sit with his or her legs underneath and would then be on a level with the loom.
Frame looms
Frame looms followed basically the same principles as ground looms. The loom was constructed out of sticks and boards attached at right angles (producing a box-like shape), which meant that it was portable and could even be held in the weaver's lap. Frame looms are still in use today, usually as a portable, less expensive, and compact alternative to a table or floor loom.
Backstrap looms
Backstrap looms, as the name implies, are tied around the weaver's waist on one end and around a stationary object such as a tree, post, or door on the other. Tension can be adjusted simply by leaning back. Backstrap looms are very portable, since they can simply be rolled up and carried.
Foot-treadle floor looms
Handweavers today tend to use looms with at least four shafts or harnesses. Each shaft contains a set of heddles through which yarn can be threaded (and attached, through a variety of mechanisms, to the front and back beams of the loom), and by raising the harnesses in different combinations, a variety of patterns can be achieved. Looms with two such shafts are called rigid heddle looms and variants with eight or more shafts are available.
The shafts on a floor loom are controlled by a series of foot pedals (called treadles). This is an important development, since it keeps the weaver's hands free to manipulate the shuttle and it is easy to raise and lower warp threads in selected combinations. As the material is woven, it can be wrapped around the front beam, as unwoven yarn is unrolled from the front beam, so length is not limited by the size of the loom. A table loom is similar, but, as the name suggests, it is smaller and equipped with levers rather than treadles, since it is made to sit on a stand or on top of a table.
Haute lisse looms
Looms used for weaving traditional tapestry are classified as haute lisse looms, where the woof is suspended vertically between two rolls, and the basse lisse looms, where the woof extends horizontally between the rolls.
Power looms
The first power loom was built by the Englishman Edmund Cartwright in 1785. Originally, powered looms were shuttle-operated but in the early part of the 20th century the faster and more efficient shuttleless loom came into use. Today, advances in technology have produced a variety of looms designed to maximize production for specific types of material. The most common of these are air-jet looms and water-jet looms. Computer-driven looms are now also available to individual (non-industrial) weavers.
The Jacquard loom
The Jacquard loom was the first machine to use punch cards. It uses punched cards to control the pattern being woven.
Reference
"The Art and History of Weaving" (http://www.faculty.de.gcsu.edu/~dvess/ids/fap/weav.html)
Warping and weaving on a warp-weighted loom (http://vt.essortment.com/warpingweaving_rkpp.htm)
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The above article is licensed under the GNU Free Documentation License. From Wikipedia, the free encyclopedia (https://en.wikipedia.org/wiki/loom). 10/31/04 |
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Weaving is the interlacing of two sets of threads at right angles: the warp, running lengthwise, and the weft, crossing it row by row. Doing this by hand without equipment is possible but slow and uneven, because the warp must be held taut, in order, and opened afresh for every single row. The loom is the device that takes over those three burdens. It stretches the warp between two points under even tension, keeps every thread in its assigned place across the full width of the cloth, and provides a mechanism — heddles, harnesses or individually controlled hooks — to lift one selection of warp threads while leaving the rest down, forming the V-shaped opening called the shed. The weft travels through the shed, the selection changes, and the weft is trapped: one row of cloth, made in seconds, repeated thousands of times into a fabric.
The remaining parts serve that cycle. The reed, a comb-like frame, pushes each new weft thread firmly against the edge of the woven cloth — the fell — so the fabric is compact and even. The warp beam at the back stores the unwoven warp and releases it gradually; the cloth beam at the front winds up finished fabric, and the two beams working in opposition keep tension constant as the work moves forward. A shuttle, where one is used, carries the weft in a continuous thread from a bobbin inside it; modern industrial looms replace the shuttle with grippers, rapiers, air jets or water jets that carry the weft faster and without a heavy moving boat of wood and metal crossing the warp.
The range of the term is the range of weaving itself. At the smallest end are hand-held frame looms, tablet weaving setups and backstrap looms in which the weaver's own body supplies the tension — technologies of great antiquity that still produce fine cloth. Large free-standing hand looms, worked by treadles and thrown shuttles, were the engines of the pre-industrial cloth trade and remain the tools of handweavers today, fitted with multiple harnesses for complex weaves or with Jacquard heads for figured patterns. At the far end stand the huge automatic mechanical looms of the mill: power looms that stop themselves when a thread breaks, change their own weft supply, and run at speeds where the weft crosses the warp hundreds of times a minute.
What does not change across that whole range is the definition's core. A loom is not defined by its power source, its size or its era, but by its function: a device for weaving thread or yarn into textiles, holding the warp so the weft can build cloth against it. The warp-weighted looms of the ancient world, the pit looms and frame looms of traditional weaving cultures, the hand looms of the cottage weaver and the air-jet looms of a modern mill are all answers to the same mechanical problem, differing in speed and complexity but identical in the geometry of shed, shuttle and reed that turns yarn into fabric.
A loom is a machine or device for weaving thread or yarn into textiles. It holds the warp threads under tension so the weft can be passed through them and beaten into place, row by row, forming cloth.
The main parts include the warp beam that holds the unwoven warp, the heddles and harnesses that lift selected warp threads to open the shed, the shuttle or other carrier that takes the weft across, the reed that beats the weft into place, and the cloth beam that winds up the finished fabric.
The shed is the opening formed when some warp threads are lifted and others are left down. The weft passes through the shed, and when the lifted threads change, the weft is locked into the weave.