Tuesday, June 9, 2009

Loom

BASIC COMPONENT OF LOOM
1. Beam
2. Back rest roller
3. Drop wires
4. Motor driving the warp let-off
5. Healds
6. The motor driving the fabric take up
7. Slay
8. Reed
9. Take-down roller
10. Cloth beam

Loom:-

Loom is the machine that is used for this purpose. In the beginning, hand looms were used to produce cloths through weaving, at a commercial scale. These looms made use of a shuttle for the insertion of weft. The weaver had to throw a shuttle by hand from one side and catch it with the other hand at the other side. Then, after several developments and after the invention of electricity, power looms were came into being. The power looms were used for centuries, with the same element for weft insertion, the shuttle. The shuttle looms seemed to fail to meet the requirement of the modern, fast and quality conscious world. This led to the invention of the looms, which could insert weft into the fabric through any other means. Such looms are termed as shuttleless looms, which can give the desired quality and production. The looms were invented many years ago, but they came across the commercial success, about 35 years ago.

The production of a loom is generally measured by its speed in picks per minute. However, the correct way for the purpose is to figure out the weft insertion rate. After the commercial success of the shuttleless looms, the speed has been increased by up to 300-400% depending on reed widths. The common projectile and rapier looms have similar speeds, which are at least 80% above the speeds of the best shuttle machines of similar width, and the air-jet machines have weft insertion rates 80-150% above those of the projectile looms.

When projectile weaving machines were successfully introduced three decades ago, they were running barely 50% faster than shuttle looms. The few rapier machines in use were slow and cumbersome, and jet machines had only just reached the prototype stage. The complete eclipse of the shuttle loom since then is mainly due to the reduced amount of labour required to operate the newer machines and the improved quality of the cloths produced on them. Greater production per machine and per unit of space reduces operating costs, but still greater advantages were obtained from the use of a supply of nearly continuous weft, smaller sheds, lighter sleys operating independently of the weft insertion unit, and the use of fewer, lighter, and better engineered components requiring less maintenance.

In recent years, the incorporation of microprocessors, for machine control and automatic adjustment, has resulted in further substantial increases in weft insertion rates.