History of water jet loom:-

History of water jet loom:-

Water-jet loom machines were first developed in Czechoslovakia in 1950’s and subsequently refined by the Japanese in the 1960’s . The first water-jet weavning machine was Kovo, which was developed by Vladimir Svaly at Research Institute for Textile Technology in Czechoslovakia and shown at Brussels in Textile Machinary Exhibition in 1955. This machine has a speed of 600 ppm a reed width of 40 inches, upto 12 harness were possible. The Prince jet loom was another earlier water jet weavning machine. It had a reed width 65" at 400 ppm speed . The width and speed of the water-jet looms gradually increased and the modern water-jet weavning machines can have a speed of around 1500 ppm while the maximum reed width is 3 meters and the filling insertion rate is 1800 mpm.

Working principle of Water-jet loom:-

Water-jet weaving machines have the same basic functions of any other type of weavning machines. The principle of filling insertion with a water-jet is similar to the filling insertion with an air-jet, they both use a fluid to carry the yarn.

However there are some differences that affect the performance and acceptance of water-jet weavning machines. For example, the yarn must be wettable in order to develop enough tractive force.

The flow of water has three phases:

1) Acceleration inside the pump prior to injection into the nozzle.

2) Jet outlet from the nozzle.

3) Flow inside the shed. The water flow inside the shed has conical shape with three regions, compact,split, and atomized.

Compact and split portion are better for yarn insertion. Due to water weight , the jet axis from a parabola which necessitate adjusting the axis of the nozzle upward by some angle. The flow of water than follows the motion of angular projection.

Unlike the air-jet weaving machine, the pump and picking system is fixed firmly to the machine frame to ensure that the beat up mechanism moves the reed only . Due to the viscosity of water and it’s surface tension, a water jet is move coherent then an air-jet. As a result the water-jet does not break up that easily and has a longer propulsive zone. There are no varying Lateral forces in a water-jet to cause the filling yarn to control. Besides , since the weft moving element is more massive, there is less chance for the filling yarn to entangle with the warp. The braking of the filling is provided by the reed.

The width of a water-jet, loom machines depends on the water pressure and the diameter of the jet. Since water is not compressible, it is relatively easy to give enough pressure to the water-jet for insertion. The diameter of the jet is around ,0.1 cm and the amount of water used for one pick is usually less than 2 C C . Double pump system, with two nozzle at will filling insertion is suitable for weaving fabrics with two different fillings.

The waste water after insertion is usually removed into a drainage system.

Advantages of Water-jet loom:-

The main advantages of a Water-jet looms are as under.

1) Water-jet loom consumes less power than others.

2) This type of loom suitable for producing synthetic fabrics.

3) Here production rate is high.

4) It creates less noise than rapier and missile (projectile) looms.

5) Flexibility during the use of multiple water-jet looms may allow operator to continue to operate efficiently on fewer drives.

6) Lowest downtime and easy maintenance routine.

7) There is no vibration during looming (weaving).

8) It produce fault less fabrics.

Disadvantages of Water-jet loom:-

A few disadvantages of Water-jet looms are as under:-

1) By using hard water, here may form rust on the yarn.

2) It is not perfect for absorbent fiber , such as cotton, wool and silk.

Ref:-https://textilelearner.net