The cop which is prepared in the ring frame is not suitable for further processing. So the yarn is converted into the shape of cone which is prepared in the winding. Practical experience shows that winding process alters the yarn structure. The factors which affect the yarn structure during winding are bobbin geometry, bobbin unwinding behavior, binding speed. This phenomenon does not affect the evenness of the yarn but it affects the properties of the yarn such as thick places, thin places, nep
After manufacturing of yarn, from different departments in the preparatory process and ring department, it is ready to make a shape into final cone form so that it can be shipped to customer for use. During winding process of yarn following objectives are met.
- Scanning and faults removing Electric Scanners (uster) are used for checking and elimination of yarn faults during winding process. This process is called Usterization of yarn. Such faults are called scan-cuts.
- Splicing of broken or cut yarn Auto splicing is done for broken yarn pieces to eliminate yarn knots and bad piecing.
- Bigger package Conversion of yarn from small ring bobbins to bigger yarn cones of different international standard or as per requirement of customer. During achieving above objectives or making of winding cones some faults are created during the process. These faults need to be controlled through monitoring and continuous study. Most of the winding faults are very dangerous for the next subsequent process which can be warping or knitting or doubling. We can face complains from customer of breakage of yarn during unwinding process.
In order to avoid any complaints from customers, faulty winding cones are separated during inspection by inspectors. Following three decisions are taken at this stage.
- Use as it is: When the fault is of some minor category, and there is no risk of next process failure during unwinding. Decision is only taken by some senior person of quality.
- Rewind: Some faults can be removed after rewinding. But rewinding itself is costly affair and quality of cones also detritus after reprocessing.
- Degraded as B grade: If fault is of such nature that rewinding can’t remove that fault and there is doubt for customers to complains then such cones are downgraded to lower grade. Degrading cones in to lower grade is again financial loss to the company.
How to maintain good quality ?
Following point should be considered for quality point of view
- Winding speed should be 1200 meter per minute for getting good quality.
- For getting good quality, yarn fault clearers device setting should be as close as possible in order to eliminate the disturbing yarn faults.
- In order to get good quality of yarn count channel setting should be less than 7%.
- Cone which we prepare for weaving purpose should have minimum fault for getting good quality, especially in the long thin places and long thick places.
- For getting good quality yarn, splice strength must be 75% more than of the yarn strength.
- Splice appearance should be good. Splice device should be checked twice in a week.
- To get better efficiency, cone weight should be 1.8 to 2.4.
- Yarn winding tension must not be high during winding. If we will keep it high then tensile properties will be affected such as elongation and tenacity.
- If waxing attachment is below the clearers, the clearers should be clean at least once in a day.
- Wax roller should rotate properly