Tuesday, January 3, 2017

Auxiliary Motions of Loom and Their Functions

In order to manufacture fabric with weaving machine three types of motions are used. They are:
  1. Primary motions
  2. Secondary motions
  3. Tertiary motions / Auxiliary motions
Auxiliary Motions of Weaving Machine:
In order to produce a high quality fabric, increase productivity of loom and to prevent damages it is necessary to use some stop motions which is provided on the loom. They are called as auxiliary motions. But auxiliary motions are useful but not must essential. Without auxiliary motions cloth produce is possible. But in industrial production auxiliary motions must need.
Auxiliary motion of loom
Fig: Auxiliary motion of loom
There are various types of auxiliary motions of loom. They are:
  • Warp stop motion
  • Weft stop motion
  • Warp protector mechanism
  • Temple
  • Weft replenishment / Weft mixing motion,
  • Brake motion
  • Weft feeder
  • Sensor
  • Feeler motion
  • Cutter
  • Light signal
  • Selvedge
Different Functions of Auxiliary Loom Motions:
  • Warp stop motion stop the loom when a drop wire fall as the result of warp end slack or break. The broken end is repaired and handled by the operator. 
  • Weft stop motion enables to stop the loom when a weft thread breaks or gets exhausted. In case the loom is allowed to run even after the weft breaks there will be no woven cloth except long threads of warp. This motion helps to avoid cracks in a fabric. 
  • If shuttle fails to reach its proper box, a loom must either be instantly stopped by a fast reed motion or gradually stopped by loose reed motion. Warp protector mechanism will stop the loom to prevent excessive damage to the warp threads, cloth, and reed if the weft carrier becomes trapped between the top and bottom of the shed lines and the reed. 
  • Temples helps to grip the cloth and hold it at the same width as the warp in the reed, before it is taken up. It may be made of wood or metal. Metal is useful for rugs. 
  • Weft replenishment ensures a continuous supply of weft yarn to the loom whenever supply package exhausted. 
  • A brake is a device by means of which artificial frictional resistance is applied to moving body in order to stop the motion of a loom. It stops the loom immediately whenever required. The weaver uses it to stop the loom to repair broken ends and picks. 
  • Weft feeders to control tension on each pick.
  • Sensors to stop the machine in the event of mechanical failure.
  • A centralized lubrication control and dispensing system. 
  • A reversing mechanism to avoid bad start ups after a machine stop. 
  • A color coded light signal device to indicate the type of machine stop from a distance.
  • A production recording system.
  • Selvedges are the narrow edge of woven fabric that runs parallel to the warp. Created by the weft thread looping back at the end of each row.