RIGHTSPUN DUE CARE points – Understanding Yarn for Weaving and Weaving Preparation

1. Strength of weak place in yarn to be 70% of parent yarn strength – Any yarn lower than this strength to be stopped from further process
2. FLUCTUATION in strength is more and more important for weaving – NOT MEAN VALUE.
3. Single Yarn Strength CV% at 15% level- yarn will not be workable at all in weaving.
If it is 13% - looms/ warping stops will be 10/hr
If it is 11% -stops can drop down to 2/hr
The increase or decrease in performance is NOT PRO RATE but GEOMETRICAL for increased fluctuation / range / CV%
4. Reduction in CV% of strength means lesser thin places in the yarn.
5. Shuttle looms – @200 mpm requires, let us say –‘ n’ g as strength in the yarn
6. For shuttleless looms - @800mpm same yarn strength is sufficient – only the CV% of SYS to be lower by 20% than the previous.
7. Both the looms will have same performance efficiency with yarns as above. There is no need for increase in the mean yarn strength for shuttleless looms.
8. Hairiness in single yarn plays a key role in performance variations at weaving.
9. It is safer to use yarn with lower hairness & lower SYS CV%, than with higher hairiness, increased mean strength & uncontrolled higher SYS CV%. Cost of richer raw material need not result in consistently better yarn, without adequate process control efforts.
10. It is important always to check / review the cost of QUALITY REQUIRED Vs actually GIVEN. No need & no necessity for giving over quality.
11. Elongation at Break is very important for warp yarn. Any E% beyond 2% - no recovery will be there.
12. Dry E% vs Wet E% (will be higher normally in cotton yarn) also is an important factor.
13. Yarn stretch levels – in process can be as under
· Winding – Maximum 10 to 15% - to remove thin places, to get tighter winding / harder package density.
· Warping – Maximum 5% - Uniform sheet of warp essential for weaving – no sagging.
· Sizing –Maximum 15 to 20% - because the yarn is wet in sizing stretch is unavoidable
· Sizing machines of year 1980 and later will have 1 to 1.5% stretch
· Newer machines less than 5yrs old will have 0.8 to 1.0% stretch
14. Higher warping stops than expected indicates failure at Conewinding to eliminate thin places – consequently higher SYS CV%.
15. Conewinding breaks can ideally be between 2 to 2.5 per 100g of yarn.
16. Warping process is the best testing laboratory for the spun yarn.
17. Hairiness is fully a spinning (RM, Process) process related problem for the weaving.
18. Sizing machine stretch to be checked in case of excessive warp stops in looms despite good warping performance.
19. Cone base dia ideally to be 4” or above for good unwinding
20. Warping barrel diameter is larger than the weavers beam barrel diameter – this is to reduce the unwinding tension at Sizing(Larger diameter – lesser tension; Smaller diameter – higher tension)
21. Warping – Flange diameter : Barrel diameter – Ratio to be between 3:1 to 4:1 (Normally 40” flange has 12” barrel)
22. Weavers beam barrel diameter of 210mm and above is good for lesser let off tension.
23. Cone hardness – ideally to be 70’
24. Conditioning is done for and expected to maintain CONSTANT MOISTURE CONTENT in the yarn.