Motions of Loom and Their Functions in Weaving Machine
Dept. of Textile Technology
Sarvajanik College of Engineering & Technology, Surat, India
Cell: +91 9662020909
The process of producing a fabric by interlacing warp and weft threads is known as weaving. The machine used for weaving is known as weaving machine or loom. In order to interlace warp and weft threads to produce a fabric, the following motions are necessary on any type of loom. Shedding, Picking, Beating, Let-off, Take-up are weaving loom motions.
The motions and their function on weaving machine or loom are as follows:
1. Primary motions of loom
- Shedding – To separate the warp thread into layers one layer is raised and the other lowered.
- Picking – To insert a weft thread across the warp Ends through the shed.
- Beating-in – To push the weft thread that has been inserted across the war ends, up to the cloth fell.
2. Secondary motions of loom
Take-up motion –
The system has the following controls:-
Tension control—The servomotor controls the warp yarn tension and slack according to the signa collected by the tension sensor. This process ensures that the warp yarn’s tension is controlled properly during opening, warp loosening, and warp let-off.
Manual warp yarn loosening and tightening—When the machine is not operating, the user can manually tighten or loosen the warp by controlling the servomotor’s forward and reverse rotator.
Fabric take-up control—This function pulls the finished cloth away from the opening in time as required by the weft density so that the position of the opening does not vary with the new weft- yarn, ensuring successful production.
A→ ETU GEAR BOX
C→ FRICTION GEAR
D→ COMPOUND GEAR
E→ SPUR GEAR
F→ DRIVE GEAR
G→ PRESS ROLL
To pull the cloth forward after the beat-up of weft, maintaining the same pick density and spacing throughout weaving of a cloth and throughout winding the woven cloth onto a roller.
Let-off – To allow the warp to unwind from the warp beam during weaving and also to maintain an average constant tension of warp as it weaves down.
3. Auxiliary motions of loom
In order to produce a good quality of cloth and to prevent damages it is necessary to have some stop motion provided on the loom. They can be termed as auxiliary motions.
Warp protector – To protect the warp thread by stopping the loom when the weft fails to reach, and box properly into either the winder during picking.
Warp stop – To stop the loom when a warp thread breaks or excessively loose.
The operating system is the following: –
- Each warp thread is passed into the bottom slit of a metallic drop wire 2,
- Which this way is supported by the thread under tension. Through the top slit of the drop wire passes the contact rail 3 composed of a u-shaped outside coating in stainless steel, of a strip of insulating material and of a flat conductive inside blade in nickel-plated copper, Provided on the upper part with a toothing.
- The contact rail 3 is part of a low voltage electric circuit, of which the drop wire 2 acts as circuit Breaker.
Weft stop – To stop the loomwhen a weft breaks or the weft runs out of the weft package.
In the case of air jet machines for staple yarn weaving, an optoelectronic weft stops motion in twin arrangement can be delivered. While the first of the two weft stop motions serves as support for the machine control, the second one records the weft threads broken in the shed or expelled.
When the first one gets the weft, which means the weft thread has travelled the predetermined distance, the loom remains running. And in case of the second one gets the weft, which means the weft thread has broken and travelled excess than the predetermined distance, it knocks-off the loom instantly.
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Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.