Wednesday, June 27, 2018

Types of Jacquard Shedding | Jacquard Shedding Mechanism in Textile

What is Jacquard Shedding in Textile?

In textile sector, the jacquard is a shed or shedding device which is placed on the top of the weaving loom for producing large figure patterns by using a very large no. of warp yarn separately by means of hooks, needles, and harness cords but without any heald shafts. 

Scope of Jacquard Shedding in Weaving:

The various scope of jacquard she or jacquard shedding has pointed out in the following:
  1. Each warp yarn can be controlled differently at any pick.
  2. The harness is used for lowering or lifts the warp yarn during weaving.
  3. No heald frame is used in the jacquard shed or shedding.
  4. Sophisticated or large or elaborate design is used for jacquard design.
  5. One warp yarn for each harness cords.
  6. Min. figuring capacity is 100s- that means min. the number of warp repeat is less than 100.
  7. Maximum figuring capacity is the 1800s+ and the maximum number of warp repeat is greater than 1800.
  8. By using the jacquard shed or jacquard shedding, the most costly fabric is produced.

Classification of Jacquard Shedding in Weaving:

There are different ways of classifying jacquard shed or shedding in textile weaving. Those are in the below:

1. According to figuring capacity:
100s, 200s, 300s ………., 1800s+

2. According to lift and number of cylinder:
  • Double lift single cylinder jacquard (DLSC),
  • Double lift double cylinder jacquard (DLDC),
  • Single lift single cylinder jacquard (SLSC).

3. According to selecting device:
  • Paper roll jacquard,
  • Jard jacquard.

4. According to pitch of jacquard:
  • Coarse pitch jacquard,
  • Medium pitch jacquard,
  • Fine pitch jacquard.

5. According to types of shedding:
  • Open shed jacquard,
  • Semi-open shed jacquard,
  • Center close shed jacquard,
  • Bottom close shed jacquard.

6. According to the source of driving power:
  • Power jacquard,
  • Hand jacquard.

7. According to position of cylinder:
  • Vertical jacquard,
  • Horizontal jacquard.

8. Method of harness mounting:
  • Single tie-up London system,
  • Repeating tie-up London system,
  • Pointed tie-up London system,
  • Mixed tie-up London system,
  • Special tie-up London system,
  • Nor-witch system.

9. Control mechanism:
  • Electronic mechanism,
  • Mechanical mechanism,
  • Mechatronics mechanism.

10. Broadly:
  • Special jacquard,
  • Ordinary jacquard.

Working Principle of Jacquard Loom in Textile:

The basic principle of the jacquard shed or shedding mechanism is described in the following with the help of single lift single cylinder (SLSC) jacquard. 
Jacquard shedding in weaving
Fig: Jacquard shedding in weaving
Punches card is used for the jacquard shed which is made according to the design. Here, one pattern card is used for the single pick with these pattern cords. Pattern chain is made which take place on the pattern cylinder. Here, pattern card holes indicate warp up of the design.

The knives form the giraffe which is all fastened together. Those are moved down and up from the weaving loom crankshaft. The pattern cards of the perforated cylinder are pressed against the needles when the giraffe begins to move upwards.

If there is a hole in the pattern cad, the needle directly opposite the hole will pass through it and into the perforation the cylinder and the knife will take if the hook to which this needle is connected and forms the top line of the jacquard shed or shedding.

It will press back the hook and as the knife lifts if the pattern card is blank opposite any needle. As a result, the hook is left down. Thus it is possible to lift any of the 408 hooks in the jacquard for any pick and from the bottom line of the jacquard shed or shedding.