JACQUARD MACHINE AND JACQUARD LOOMS:-

Jacquard machine and Jacquard loom:-

The Jacquard machine is a device fitted to a loom that simplifies the process of manufacturing textiles with such complex pattern as brocade, damask.

The resulting assemble of the loom and the Jacquard machine is then called “Jacquard loom” . The machine was patented by Joseph Marie Jacquard in 1804 based on the earlier invention by Frenchman Basile Bouchon(1725), Jean Baptiste Falcon (1728), and Jacques Vaucanson (1740). The machine was controlled by a number of punched cards laced together into a continuous sequence. Multiple rows of holes were punched on each card, with one complete card corresponding to one row of design.

A jacquard loom showing information punched card in National museum of Scot land.

Both the Jacquard process and the necessary loom attachment are name after their inventor. This mechanism is probably one of the most important weaving innovation as Jacquard shedding made possible the automatic production of unlimited varieties of complex pattern weaving. The term “Jacquard” is not specific or limited to any particular loom, but rather refers to the added control mechanism that automates the patterning. The process can also be used for pattern knitwear and machine knitted textile such as jerseys.

The use of replaceable punch cards to control a sequence of operation is considered an important step in the history of computing hardware, having inspired Charles Babbage’s Analytical Engine.

Principle of operation:-

Jacquard digram :- the numbered components are as described in the text.

19th century engineering drawing of Jacqloom.

On the diagram cards are fastened into continuous chain (1) which passes over a square box. At each quarter rotation of a new card is presented to jacquard head which represents one row ( one “pick" of the shuttle carrying weft). The box swings from the right to the position shown and presses against the control rods (2). Where there is a hole in the rod passes through the card and is unmoved whereas if the hole is not punched to the left. Each rod acts upon a hook (3). When the rod is pushed in , the hook moves out of position to the left, a rod that is not pushed in leaves it’s hook in place. A beam (4) then rising under the hook and those hooks in the rest locations are raised, the hooks that have been displaced are not moved by the beam. Each hook can have multiple cords (5). The cords pass through a guide (6) and are attached to their handle (7) a return weight (8). The heddles raise the warp to create the shed through which the shuttle carrying the weft will pass. A loom with a 400 hooks head might have four threads connected to each hook, resulting in a fabrics that is 1600 warp ends wide with four repeat of the weave going across.

 The term “Jacquard loom" is some what inaccurate. It is the “Jacquard head" that adopts to a great many dobby loom that allow the weaving machine to then create the intricate patterns often seen in Jacquard weaving.

Jacquard driven loom , although relatively commonly in the textile industry are not as ubiquitous as dobby looms which are usually faster and much cheaper to operate. However dobby looms are not capable of producing so many different weaves from one warp . Modern jacquard machine are controlled by computers in place of the original punched cards and can have thousands hook.

The threading of a jacquard machine is also lebour-intensive that many looms are threaded only once. Subsequent warps are then tied only into the existing warp with the help of a knotting robot which ties each new thread on individually. Even for a small loom with only a few warp ends the process rethreading take days.

Ref:-https://en.m.wikipedoa.org