Single lift single cylinder (SLSC) Jacquard Shedding Mechanism

The Jacquard shedding mechanism is a type of shedding mechanism used in weaving machines to create complex patterns and designs in woven fabrics. Here’s how it works:

  1. The Jacquard shedding mechanism uses punched cards to control the movement of the warp threads.
  2. Each card in the sequence represents a single row of woven fabric and contains a series of punched holes.
  3. When a card is placed in the Jacquard machine, it is read by a series of pins that control the movement of the warp threads.
  4. As the pins engage with the holes in the card, they selectively raise or lower the corresponding warp threads, allowing the weaver to create intricate patterns and designs in the fabric.
  5. The Jacquard shedding mechanism is capable of producing very complex designs, as the number of cards and the patterns of the punched holes can be varied to create an almost limitless range of designs.
  6. Compared to other shedding mechanisms, such as the dobby or cam shedding, the Jacquard shedding mechanism offers the greatest flexibility in the design of woven fabrics.
  7. Jacquard shedding is widely used in the production of high-end textiles such as damasks, brocades, and tapestries. The development of computerized Jacquard shedding machines has made it possible to create even more intricate designs in woven fabrics.

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 repeats is less than 100.
  7. The 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 various 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 several cylinders:

  • 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 a 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 the position of the 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:

The basic principle of the jacquard shed or shedding mechanism is described in the following with the help of a single lift single cylinder (SLSC) jacquard.

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. A pattern chain is made which takes place on the pattern cylinder. Here, pattern card holes indicate warp-up of the design.

With every 1/4th rotation a new card comes front of the cylinder in the hook side and for the two and fro movement the needles enter inside the holes of the punch card. This selection of entrance inside the punches of the needles is actually done according to design.

If a needle enters in the hole of the card the needle remains stationary in its position. So the needle crank also remains stationary in its position. So for the upward movement of the knife the hooks also goes upward along with the warp threads to form the top line.But if needle gets no perforation to enter, the hook is pushed to the right and as result the needle crank takes away the hook along with it. So when the corresponding knife goes upward it cannot lift the hook with it. Thus the warp ends of those hook remains fixed in its position and form the bottom line.

After certain time the knife releases two hooks which is lifted to form the top line and due to wrap tension and dead weight the heald eye comes down. Its downward movement is controlled by grid bar. Each needle has a spring push at its right and that spring pushes back the needle when the next card comes.

Suggestions:

Jacquard Shedding mechanism is extremely useful for producing designed cloth a number of disadvantages hampered the shedding. We’ve to ensure the fault-free shedding method in the jacquard shedding mechanism.

Reference:

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