What is Jacquard Mechanism? Shedding in weaving is the separation of the warp sheet into two layers to form a tunnel known as the shed. Different mechanisms are used for shedding. They may be grouped as tappet mechanism, Dobby mechanism and Jacquard mechanism. Jacquard mechanism is hard than other mechanism. It is true that, many difficult design can be produce and large fabric can produce by this mechanism. In this article I will discuss about jacquard mechanism and its characteristics, advantages and disadvantages.
Jacquard mechanism offers unlimited patterning possibilities. Jacquard is a system of weaving that utilizes a highly versatile pattern mechanism to permit the production of large, intricate designs. The weave pattern is achieved by a series of punched cards. Each card perforation controls the action of one warp thread for the passage of one pick. The machine may carry a large number of cards, depending upon the design, because there is a separate card for each pick in the pattern. Although they are simple in principle, jacquard machines contain many parts which make them relatively costly to install and maintain. Jacquard mechanisms are more liable than dobby or cam shedding to produce faults in the fabric.
Fig: Jacquard mechanism
Jacquard patterns, when carefully analyzed, may be seen to contain combinations of plain, twill, and satin weaves, even in the same crosswise yarn. Many decorative fabrics are made by the jacquard technique. Yarns woven into unlimited designs, often intricate, multi-color effect. Expensive, but the design do not fade or wear out. Durability depends on the fiber used. The Jacquard loom was invented by Joseph Marie Jacquard. In Jacquard fabrics Warp is individually controlled with each pick passage creating intricate designs.
Jacquard machines can be mechanical or electronic with single or double lift mechanisms; the new machines are all double lift. Recently, more modern jacquards utilize electronic systems for input of the harness lifting and lowering patterns. Modern jacquard heads generally are equipped to handle over 1200 harness cords with patterns repeating on about 9000 picks and multiple heads can be employed over a single weaving machine to increase the weave pattern capability.
Jacquard mechanism is used for tapestry, brocade, Damask, brocatelle, figured necktie and dress fabrics, and some floor coverings.
Characteristics of Jacquard Mechanism:
For designs that require the reproduction of freely drawn shapes, it is usually necessary for each end in the repeat to be separately controlled.
Jacquard machines are used for a wide variety of purposes from ties to carpets.
Their patterning possibilities virtually unlimited.
The most elaborate designs (reproduction of freely drawn shapes, i.e. floral designs) are woven on an intricately constructed loom called the Jacquard loom, and the weave of these fabrics is called the jacquard weave.
Elaborate designs could not be made on the regular harness loom. Because intricate designs require many variations in shedding.
Virtually no limit to the number of picks / repeat (i.e. 5000 picks or more).
The length of the repeat is limited only by the cost and inconvenience of a very long pattern chain.
Jacquard machines are made in a wide variety of sizes to control from 100 to 2000 or more ends per repeat.
In conventional jacquard machine field, the spectrum now ranges from 192 through 3200 to 6144 hooks.
When a higher no. of independent lift is required two or three jacquard machine is placed side to side.
Advantages of Jacquard Mechanism:
Tremendous design possibilities,
Simpler in principle than dobbies
Disadvantages of Jacquard Mechanism:
Large scale moving parts makes the machine and its harness relatively costly to install and maintain.
Jacquard fabrics are much more costly to produce.
Jacquard machines are even more liable to produce faults in the fabric than dobbies.
Pattern change is a time consuming process.
Until recently, the jacquard machine had tended to impose limitations (300 picks/min )
Jacquard shedding is normally used only when the cloths to be woven are outside the scope of dobby shedding.
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. Mr. Kiron is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
