Such operations include brushing of the warp sheet, combing and fixing both the ends face to face in sheet form in a fixed stand. The knotting unit or tying unit inserts knots and joins both the warp yarn from the yarn sheets at a speed of 500 to 600 knots per minute depending on the count and density of threads.
In an effort to reduce knotting operation time, Piyush Chandarana, general manager-Material with the Denim Division of RSWM Ltd, LNJ Group's flagship company located in Banswara (Rajasthan) has developed a new concept, whereby certain operations are eliminated during knotting to save time and improve utilisation.
The new proposed concept, according to Piyush, reduces the knotting operation time drastically while it increases the efficiency of the loom shed (by at least 0.25 to 1.35 %). Though more floor space will be required to implement this concept, the merits are much higher and hence worth implementing. The benefits and success rate expected are more in the case of coarse counts and less denser fabrics. However, it is worth taking trials and modifications for finer and highly denser varieties also, says Piyush.
Highlighting the new concept and comparing it with traditional system operations, Piyush says, "Normally, loom has to be stopped for knotting and restarted after completion of knotting with new warped/sized beam, but in the new concept, warping beam/sized beam is hollow from inside (like barrel) through which the yarn sheet (converted into rope form) during sizing gets passed and this hollow beam is knotted with earlier running warp beam by distributing rope with help of cello tape."
Adding further, he says: "Once, running warp beam is completed, rope is removed from hollow section through slot in hollow barrel as well as side aluminum disc. Following this, the new beam will be directly connected with loom and without loosing much time, we can start the loom. Also, if there is any twist in rope due to running of warp beam, we can rotate new beam and remove twist."
Talking about the merits and demerits, Piyush says that through this new arrangement, the overall installed efficiency of the loom shed is expected to increase by almost 0.5 - 1.5%, while the loss on account of Knotting operation time will substantially reduce. Not only this, the benefits also include lesser human involvement and time consumed to complete the operation. However, there will be few disadvantages too, such as: (a) The space requirement may increase in the existing set up; (b) Leasing will be a difficult task; (c) Chances of entanglement will be there, if not handled carefully; and (d) The new operation may create problem for denser and finer counts.
For better understanding of the concept, Piyush has made drawings, which give a fair idea for all those who wish to implement the concept to achieve reduced downtime and enhanced productivity. With the drawings, Piyush gives the following notes to help those implementing the concept:
1. Once the running warp beam is exhausted, knotting is also simultaneously finished. Yarn from the new full beam will be removed from the slot of the running beam.
2. Now, running beam will be separated from the yarn and there is direct connection of new sized beam with loom.
3. Due to knotting during running of beam, there may be twist of yarn bunch. Such twist will be removed by rotating new beam.