From Academic Kids
- For the graphical adventure game, see LOOM.
In practice, 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.
- See Weaving for more information.
- See Textile manufacturing terminology for more terms connected with looms.
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 BC.
Types of looms
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.
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 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, 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.
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.
Industrial looms can weave at speeds of six rows per second and faster.
The Jacquard loom
The Jacquard loom was the first machine to use punch cards. It uses punched cards to control the pattern being woven. It is a form of dobby loom, where individual harnesses can be raised and lowered independently.
- Template:US patent -- Loom
- "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)de:Webmaschine