trouble shooting in Air jet Looms for Denim

Here are some of the common fabric defects and their troubleshooting as observed on Denim weaving Airjet looms. I have included the damages observed on Tsudakoma looms, but I am sure the principles can be applied on other airjet looms also:

a. Bent Pick

1. Check catch cord drawing in and its position
2. Air pressure of all nozzles
3. Heald Frame height and shed crossing
4. Check stretch nozzle timing and position
5. Reed dent gap opposite to stretch nozzle.
6. Check condition and position of weft rubber stopper.
7. H1 Feeler head condition to check for any damage etc.
8. Heald frame side play to check
9. Binding of Leno Yarn

b. Weft Patti

1. Check pressure of AGS
2. Check AGS piston
3. Check beam gear and beam drive pinion
4. Check beam bearing bush, clamper condition and beam bearing
5. Check ELO timing
7. Check tension lever rod freeness and shock absorber position
8. Check take up gear and take up belt condition
9. Check press roll spring tension
10. The machine should not be stopped for long duration
11. Train workmen to follow work instructions for first pick insertion

c. Weft Float

1. Check Air pressure
2. Check leakage of air pipes
3. Check nozzle jet timing
4. Check catch cord end drawing in position
5. Check stretch nozzle position against reed dent gap.
6. Check heald frame height and shed crossing timing
7. Check fringe length
8. Check LHS cutter timing
9. Check position and condition of rubber stopper
10. Check proper winding of weft turn on FDP
11. Check individual subnozzles for blowing
12. Check all warp ends are tight enough
13. RH/LH selvedge should run on last ring of the temple.

d. Missing End / Chira
1. Check all serrated bars are not in loose contact at the clamp
2. Serrated bars should be thoroughly cleaned with petrol/thinner
3. Dropper sensitivity to be checked
4. Electric connection at the cable with clamp should be checked.
5. Remove fluff from the serrated bars
6. Ensure that each warp end is attached with one drop pin.

e. Torn or Hole at the Temple

1. Check that temple cover is face to face with temple bracket
2. Ensure that temple bracket are fitted firmly on temple bar
3. Check heald frame height and shed crossing timing.
4. Check warp tension
5. Check bottom guide bar setting
6. Check press roll spring tension

f. Abrasion Mark
1. Check position of warp stop motion separator
2. check cross ends
3. Check freeness of heald wires.
4. Check emery roll for any cuts etc.
5. Check freeness of temple rings
6. Check smoothness of temple covers
7. Bottom guide bar position and condition to be checked
8. Check reed-dent spacing

g. Nozzle Mark

1. check sub nozzle angle and height
2. Check scratches at tip of sub nozzle
3. Sub nozzles should be parallel
4. Check Reed dents

h. Jirky/ Missing Pick
1. Check working of H1/ H2 feeler
2. Check feeler timing in I-board
3. Check setting of FU-203 (sensitivity of H1 and H2 feelers)
4. Clean H1 and H2 Feeler head

i. Tight Ends
1. Check that ends should be parallel
2. Remove entanglement of warp ends
3. Check that sticky ends of selvedge should not run in the body.

j. Oil Daghi

1. Check that no oily fluff is stuck to the warp sheet
2. Check that no oily fluff is stuck to the emery roll or pressure roll.

k. Bad selvedge

1. Check leno stop motion
2. check proper RH cutter setting
3. Check continous working of batching winder