Jacquard machine

History

Traditionally, figured designs on a drawloom required a second operator, the draw boy, to manually select heddles. In the second half of the 15th century, an Italian weaver from Calabria known as Jean le Calabrais, invited to Lyon by Louis XI, introduced a machine that worked yarns faster and more precisely. In 1725, Basile Bouchon applied a perforated band of paper to improve the draw loom. Joseph Marie Jacquard developed a mechanism that combined elements of earlier inventors, notably using Jean-Baptiste Falcon's individual pasteboard cards and square prism, and fully perforating each of its four sides, replacing Vaucanson's perforated barrel.

Jacquard's machine contained eight rows of needles and uprights, increasing figuring capacity. Unlike previous damask-weaving machines, the figuring shed could be drawn on every shot, producing fabric with greater definition of outline. Jacquard's invention deeply influenced Charles Babbage.

Principles of operation

Cards are fastened into a continuous chain that passes over a square box. At each quarter rotation, a new card is presented to the Jacquard head, representing one row of the weave. The box swings and presses against control rods; for each hole in the card, a rod passes through unmoved, while where there is no hole, a rod is pushed left, acting upon a hook. A beam rises under the hooks, raising those left in place; displaced hooks are not moved.

Each hook can have multiple cords attached to heddles and return weights, raising the warp to create the shed for the shuttle. A loom with a 400-hook head might have four threads per hook, producing a fabric 1600 warp ends wide with four repeats. The Jacquard head adapts to many dobby looms. Jacquard-driven looms are less common than dobby looms, which are faster and cheaper, but dobby looms cannot produce many weaves from one warp.

Modern jacquard machines are computer-controlled and can have thousands of hooks. Re-threading a Jacquard machine is labor-intensive and can take days.

Electronic Jacquard machines

In 1855, a Frenchman adapted the Jacquard mechanism to work by electro-magnets, but trials were unsuccessful and the development was forgotten. Bonas Textile Machinery NV launched the first successful electronic Jacquard at ITMA Milan in 1983. Modern technology allows single end warp control for more than 10,000 warp ends, eliminating the need for repeats and symmetrical designs. Computer-controlled machines reduce downtime from changing punchcards, enabling smaller batch sizes.

Electronic Jacquards are costly and may not be necessary for large batch sizes and smaller designs. Larger machines with single-end warp control are very expensive and justified only for great versatility or specialized designs, such as niche linen Jacquard weaving in Europe and the West. Linen products include damask napery, apparel fabrics, and bed linen.

Importance in computing

The Jacquard head's use of replaceable punched cards to control a sequence of operations is considered an important step in computing history. Changing the pattern by simply changing cards was a conceptual precursor to computer programming and data entry. Charles Babbage knew of Jacquard machines and planned to use cards for his Analytical Engine.

Herman Hollerith later used punched cards for data input in the 1890 United States census, leading to a large data processing industry. Some early computers, like the 1944 Harvard Mark I, received program instructions from punched paper tape. Punched cards remained in computing use until the mid-1980s.

Did You Know?

• A prayer book woven in silk, Livre de Prières, was produced using a Jacquard machine in 1886–1887 in Lyon, France, requiring an estimated 106,000 to 500,000 punchcards.
• The woven silk prayer book was displayed at the 1889 Exposition Universelle and took two years and almost 50 trials to complete.
• An earlier title, Les laboureurs (1878), is considered the true first book 'printed' by computer, using the Jacquard punch-card method.