Jacquard weaving
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Jacquard weaving makes possible in almost any loom the programmed raising of each warp thread independently of the others. This brings much greater versatility to the weaving process, and offers the highest level of warp yarn control. This mechanism is probably one of the most important weaving inventions as Jacquard shedding made possible the automatic production of unlimited varieties of pattern weaving.
In former times, the heddles with warp ends to be pulled up were manually selected by a second operator, apart from the weaver. This was known as a drawloom. It was slow and labour intensive, with practical limitations on the complexity of the pattern.
The Jacquard process and the necessary loom attachment are named after their inventor, Joseph Marie Jacquard (1752 - 1834). He recognized that although weaving was intricate, it was repetitive, and saw that a mechanism could be developed for the production of sophisticated patterns just as it had been done for the production of simple patterns. (Similar ideas were pursued by others before 1750, but Jacquard perfected and popularized the concept by about 1803.)
[edit] Mechanical jacquard looms
Originally the jacquard machines were mechanical, and the fabric design was punched in pattern cards which were joined together to form a continuous chain. The Jacquards often were small and only independently controlled a relatively few warp ends. This required a number of repeats across the loom width. Larger capacity machines, or the use of multiple machines, allowed greater control, with fewer repeats, and hence larger designs to be woven across the loom width.
A factory must choose looms and shedding mechanisms to suit its commercial requirements. As a rule the more warp control required the greater the expense. So it would not be economical to purchase jacquard machines if one could make do with a dobby mechanism. As well as the capital expense, the jacquard machines are also more costly to maintain, as they are complex and require higher skilled personnel; also an expensive design system will be required to prepare the designs for the loom, and possibly also a card-cutting machine. Weaving will be more costly as jacquard mechanisms are more liable to produce faults than dobby or cam shedding. The looms will not run as fast, and down time will increase as it takes time to change the continuous chain of cards when a design changes. Therefore with mechanical jacquards it is best to weave larger batch sizes.
[edit] Electronic jacquard looms
Bonas Machine Company Ltd. launched the first electronic jacquard at ITMA, Milan in 1983. Although the machines were initially small, modern technology has allowed jacquard machine capacity to increase significantly, and single end warp control can extend to more than 10,000 warp ends. This avoids the need for repeats and symmetrical designs and allows almost infinite versatility. The computer-controlled machines significantly reduce the down time associated with changing punched paper designs, thus allowing smaller batch sizes. However, electronic jacquards are costly and may not be required in a factory weaving large batch sizes, and smaller designs. The larger machines allowing single end warp control are very expensive, and can only be justified where great versatility is required, or very specialized design requirements need to be met. For example, they are an ideal tool to increase the ability and stretch the versatility of the niche linen jacquard weavers who remain active in Europe and the West, while most of the large batch commodity weaving has moved to low cost areas.
Linen products associated with Jacquard weaving are linen damask napery, Jacquard apparel fabrics and damask bed linen.
Jacquard weaving of course uses all sorts of fibers and blends of fibers, and it is used in the production of fabrics for many end uses. Research is under way to develop layered and shaped items as reinforcing components for structures made from composite materials.
The term "Jacquard" is not specific or limited to any particular loom, but rather refers to the added control mechanism that automates the patterning.
