Last updated on August 26th, 2023 at 11:49 am
The jacquard harness is the system of cords, healds and lingoes that transmit the movement of the hooks to the individual warp threads. A simple form of harness is represented in the fig. below:
There are two main types of harness ties.
- Norwich system.
- London system.
When jacquard mechanism is mounted with the parallel of the loom is called Norwich Jacquard. In this jacquard the long rows of needles are parallel to the comber board & at the right angle to the warp. The cords will be at the front or at the back or at both front & back of the loom.
When the jacquard mechanism is mounted at one end of the loom and at 90˚ angle of the loom is known as London Jacquard. In this system the jacquard is turned through a right angle the cords stay at the side of the loom.
The both tie systems are divided into the following four types.
- Single tie-up.
- Repeating tie-up.
- Pointed tie-up.
- Mixed tie-up.
Single tie-up: (For asymmetric design)
In this system only one harness cord is attached to one neck cord. There are must be as many hooks as there are threads in the width of the fabric. If the design is required to be woven 400 ends there are 400 hooks in the jacquard.
No. of neck cord = No. of harness cord = No. of warp in a repeat
This tie is used to produce a fabric containing only one repeat across the width of the fabric.
This is the most common design tie used for both Norwich and London harness ties. In this tie there must be as many harness cards tied to each neck cord as there are 4 repeats in the full width of the fabric. If there are 4 repeats of the pattern then there will be 4 harness cords tied with each neck cord.
No. of neck cord = No. of jacquard
This type of tie is used to produce a fabric having more than one repeat across the width of the fabric.
Pointed tie-up: (Single repeat)
This tie up is widely used where pointed draft is used and for symmetrical design if turned over its center line. Suppose a design has 800 ends. Then it is divided in to two groups i.e. 400 ends in each group. So there are required 400 ends in each group. So there are required 400 Neck cords. In this system two harnesses is attached with one neck cord.
This tie up is used to produce symmetrical design which turned over its center line.
In this tie up a large number of harness cord is used. A great skill is required of designer because the design required a greater capacity of the jacquard that has been actually used.
This tie is used if a large repeat pattern is to be produced with the existing capacity of the jacquard.
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