Weaving defects and trouble shooting for fabric woven on air jet looms

Abstract:

Air jet looms are used in the industry for production of high quality apparel fabrics and mostly for denim fabrics. Indian companies are producing fabric in millions of metres per annum while the export potential still remains weak. The main reasons for poor exports are quality of fabric not compatible with world class manufacturing with cost effective weaving, subjective decisions in four point fabric inspection system, urgency of delivery due to low production and retention of skilled manpower in a particular industry. Based on shop floor experience,we can avoid aforesaid faults by maintaining a system with regular follow up.

Introduction:

We will discuss the settings for Tsudakoma looms in supporting examples while implementation in other looms like Toyota Air jet weaving, Picanol Air jet weaving etc can be made with the help of Machine Manufacturers Manual, with some changes.

Weavers Beam Preparation:

Warping and sizing of beam needs full precaution and follow up of technical parameters.Correct selection of sizing ingredients and use of the same in adequate quantity with specified temperature, humidity, and concentration is very important to make beams. For economic and effective sizing, steam and air leakage must be attended to during the maintenance schedule.

Beam Gaiting or Knotting: Gaiting and knotting are important processes to prevent warp breakages and significantly affect the efficiency and quality of fabric.

Air Jet Looms:

Maintenance Checklist (Frequency can be maintained six monthly/annually) depends upon RPM of loom and follow up of outcomes.

Weaving Defects & Trouble Shooting

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. H1 feeler head condition to check for any damage.

7. Heald frame side play to check.

8. Binding of leno yarn.

Nozzle mark

1. Check sub nozzle angle and height.

2. Check stretches at tip of sub nozzle.

3. Sub nozzles should be parallel.

4. Check reed dents.

Jirky / missing pick

1. Check working of H1 & H2 feeler.

2. Check feeler timing in i-board.

3. Check sensitivity of H1 and H2 feelers.

4. Clean H1 & H2 feeler head.

5. Check take up belt & gears, beam pinion condition.

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.

Bad selvedge

1. Check leno stop motion.

2. Check proper RH cutter setting.

3. Check continuous working of batching winder.

Weft Patti

1. Check beam gear and beam drive pinion.

2. Check beam metal bush, clamper condition & bearing.

3. Check ELO timing, check tension lever rod freeness & shock absorber position.

4. Check take up gear & take up belt condition.

5. Check press roll spring tension.

6. Loom should not stop for long duration.

Missing end (chira)

1. Check all serrated bars are not in loose contact at clamp.

2. Serrated bars should be thoroughly cleaned/should be polished with Brasso.

3. Dropper sensitivity to be checked regularly.

4. Electric connection at the cable with clamp should be periodically checked.

5. Remove fluff from the serrated bars/drop pins.

6. Ensure that each warp end is attached with one drop pin.

7. To check WSM bar functioning frequently, if failure recurs.

Abrasion mark

1. Check position of warp stop motion separator.

2. Check cross ends.

3. Check condition of Heald wires.

4. Check emery roll for any cuts etc.

5. Check smoothness of temple covers.

6. Check if temple rings are free.

7. Bottom guide bar position and condition to be checked.

8. Check reed dent spacing.

Torn or hole at the temple

1. Check that temple cover is face to face with temple bracket.

2. Ensure that temple bracket is 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.

Microprocessor-Based Controls

With airjet looms, we can achieve better efficiency and good productivity, thanks to the microprocessor-based controls. This means that the weaving team can analyse the following details in time and prevent losses at Grey stage:

1). More warp breakages

2). More weft breakages

3). Stoppages due to mechanical reasons

4). Idle stops in terms of breakage per hour

5). Time taken by weaver to attend the loom

6). Alarms for due maintenance/lubrication schedule

7). Production evaluation in terms of loom efficiency, woven meters, picks inserted, total loom running hours etc.

8). Control on piece length by alarming signals.

9). Graphical analysis to control cost of production, various defect occurrence during running loom, etc.

10). Weave change is possible without any mechanical changes.

11). RPM of loom can be changed without replacing motor pulley.

12). PPI can be changed from microprocessor.

If Weft Feeler Head becomes loose during weaving it will be recognised from display. In this way, loom can be attended before the particular part breaks. One of the more advantage of this facility has been observed that if Reed screw remain slightly loose , feeler will vibrate as mounted on Reed so further break down can be avoided by attending loom in time.

Conclusion:

The majority of fabric can be woven on air jet looms with the approach of zero defect fabrics, by maintaining an efficient follow up of maintenance schedule and troubleshooting methods according to everchanging requirement, and market trends. The performance of the air jet loom does not deteriorate by its long term usage as long as its scheduled maintenance and lubrication is done properly. Manufacturers have large number of air jet looms with microprocessor-based controls. The only limiting factor is that everyone must play their role with an eye on results.

Acknowledgement:

We are grateful to Dr. A.K. Sharma Director- ATIRA & Mr. K.K. Misra, CEO- ATIRA.

References:

1.       Indian Textile 2015 by Jay Narayan Vyas

2.      Air jet looms Operational & Maintenance Manual

3.      Tsudakoma.co.jp

4.      Picanol.be

5.      Toyota-industries.com

Pradeep Kulshrestha is an experienced technical professional in the field of textile operations management with more than three decades of rich experience in nine esteemed companies in India and abroad. He is currently Head of Department, working for continuous development in the field of technical textiles and composites at ATIRA in the Incubation Centre (Centre of Excellence).

Dharmendra Goswami is an experienced weaving professional in the field of modern weaving machines and has a decade of experience. He is working with ATIRA Incubation Centre as Business Development Officer.