Suggestion to Reduce Autoconer Cuts in P/V & P/A Dyed Yarn
Dr. N.N. Mahapatra
CText FTI (Manchester)
Business Head (Dyes)
Shree Pushkar Chemicals & Fertilisers Ltd,
301/302, 3rd Floor, Atlanta Center, Sonawala Road,
Goregaon (East) Mumbai MH 400063
Nowadays the high autoconer cuts have become very severe in dyed fiber spinning mills. Every time there is a tussle between the spinning department and fibre dyehouse. In some mills this problem becomes more acute during rainy season. These problems can be solved by mutual consultation of raw material, spinning and dyehouse.
Fig: Autoconer
Spinning department: Please go through the cuts report and after analysis following steps can be taken or checked.
If there is problem of high short cuts:
The major area of action should be at Blow Room and card:
1. Please look into the following:
Increase the Flat speed to 200 to 230 mm/min
Increase the Cylinder speed to 480rpm.
Wash the card wire with petrol once in every 2 days.
Check the bad cards and grind the same.
Take card wise trial to identify bad cards and then these cards can be corrected quickly.
2. In addition to this trials can be taken with higher LV-40 but keeping water at 0.5 to 1% only.
3. A pre-opening before blowing action will be better. Maximum two beaters (Pin type only) in blowroom after pre opening can be used. It is advised not to use any Licker-In type beater in Blow Room. Beater pegs and lattice conditions in Blow Room Line to be checked.
4. Card settings to be checked properly:
Licker In to feed plate–40 to 50 thou
Cylinder to Flat–12/12/10/10/10
5. Roving twist can be increased by one step to reduce short cuts.
6. Apron life at R/F should not be more than 9 to 10 months for Indian aprons. For Hokusin aprons the life can be 18 months.
7. It depends on the type of clearer and its setting at winding. It has been found that use of capacitor type clearer for dyed yarns is better.
Looking to more short thick faults, it appears that the opening of the fibre is insufficient. To overcome this the following measures are suggested:
The dyed psf has to opened by blender more intensely before layering. After layering also give preferably 2 blender toppling.
At card the opening has to be increased. It may be necessary to increase the LI, Cylinder and Flat Speeds. When Li Speed is increased, it is advised to keep The Feed Plate to Li setting at 32 to 34 thou.
2152P is a binding agent, and its excess use is sure to lead to more N & S thick faults.
Therefore please try following combination of over spray:
LV-40- 0.50% to 0.55
2152P – 0.15%
Water – 3%
Further steps can be taken as follows:
If the type of clearer in autoconer for Dyed yarns is of Capacitor type clearers, then faults can be controlled.
The solution will depend on the type of clearer cuts in winding. Is it short or long cuts? In case of short, you must look at carding and simplex. In case of long cuts, then D/F and S/F should be looked into. Ensure that there should not be any lapping at D/F and S/F?
44mm and 38mm fiber should not be mixed together? This will create drafting wave variation at D/F and S/F. Better to go for 1.4X38mm fiber for all the components.
Increasing T.M. at S/F and this will help in reducing the cuts. Reduce water and increase OIL content in mixing.
The season is rainy and hence the RH in the department will be high. So the solution is to keep moisture in mixing not more than 0.5% and the oil content in mixing should be increased. This will help in running at Simplex.
Arranging Lamp on simplex creel also may help. Four 1000 watt lamp over simplex creel will be enough. Also maintain a temperature of 31 to 32ºC and RH of 46 to 48% at speed frame will help in running this.
After buffing treat the top rollers with CTC or UV lamp. A liquimix treatment will also help.
Dye House: Looking into more autoconer cuts in Navy blue shades in 2/30, 2/40 P/V and P/A in spinning during month of June, July and August.
Following trials can be taken in polyester fibre dyeing.
Reason – So before dyeing the oligomers are removed at 130ºC under alkaline conditions.
TRIAL – 2:
Monthly m/c cleaning, then dyeing process as usual but after first HT drain at 130ºC and again fill water and again take the temp to 130ºC and do the second HT drain.
Reason – Oligomers get drained out at 130ºC. So if we do two times more oligomers are removed, which is good for spinning.
Drawbacks – There will be improvement but time, steam chemical cost will go high. If established it can be used only during June, July and August.
Another alternative can be tried to improve the working performance in spg. “Dark & Heavy Dark Shades”
Afilan OR liq (Clariant) in reduction clearing bath. It is observed that sometimes the grey fibre do contain Oligomers which has to be removed before dyeing process) at the same time the fibre dyeing process itself generate the Oligomers .
If the dyeing is carried out at higher temperature i.e. more than 135ºC temperature the chances of oligomer generation are increased to a greater extent (safe temperature is 128 to 132ºC). So as to improve the performance of dyed polyester fibre in the spinning mills we feel Pre dyeing Reduction clearing with 0.5 GPL AfilanOR along with mild dosage of Caustic Soda and Sodium Hydrosulphite (at 90ºC for 5 min) followed by normal post dyeing RC with 2 GPL AfilanOR along with normal dosage of Caustic Soda and Sodium Hydrosulphite (at 90ºC for 10 min) will help to the spinners to improve the productivity as well as quality of the yarn.
There are also special machine cleaning process for oligomer descaling and removal during the dyeing process.
M/C Cleaning Procedure to Clean Oligomer Scaling from Dyeing Machines
Objective: Depending on the scaling of oligomer deposits inside the dyeing vessel, carrier holes are closed, white powder deposits etc then accordingly the type of machine cleaning procedure can be selected. If possible once a while the pump can be taken out and see if any oligomer scaling is there.
Such type of machine cleaning is required because chances are there oligomer deposits inside the pipe lines also.
Complete M/C Cleaning (Once A Year)
Chemicals to Be Used
Strong dispersing agent – 5 GPL
CAUSTIC – 15 GPL
HYDROS – 1 GPL
Non-Ionic Detergent – 0.5 GPL
Steps:
Take one empty carrier in the m/c
Add the above chemicals
Run at room temp for 10 mins
Raise temp to 130ºC and hold temp for 4 hrs, pump running.
Stop pump and heating.
Leave it for 4-5 hrs
Take out the empty carrier
Wipe the empty carrier & inside of the dyeing vessel with hessian cloth it will shine like new carrier.
Put the other empty carrier
Leave it for 4-5 hrs
Again start pump raise to 135ºC and hold for 2 hrs.
H.T. drain
Hot wash at 95ºC with non-ionic detergent -0.25 gpl, for 10 mins.
Drain
Neutralize at 95ºC with acetic acid -2 gpl.
Drain
Cold wash
Unload empty carrier.
Wipe the empty carrier & inside of the dyeing vessel with hessian cloth. It will shine like a new carrier.
Total time required – 18-19 hrs.
Routine Cleaning Once A Month
Chemicals to Be Used
Strong Dispersing Agent – 2 Gpl
Caustic – 5 Gpl
Hydros – 0.5 Gpl
Non-Ionic Detergent – 0.25 Gpl
Steps:
Take one empty carrier in the m/c
Add the above chemicals
Raise temp to 135ºC.
Hold for 1 hr with pump running.
H. t. drain
Neutralize with acetic acid -1 gpl
Hot wash with non-ionic detergent – 0.25 gpl at 90ºC. for 10 mins.
Hot drain
Cold wash
Unload empty carrier.
Repeat the same process for the other empty carrier
Both the time wipe the empty carrier & inside of the vessel using hessian cloth. Both will shine like new
Total time required – 7-8 hrs
ABOUT THE AUTHOR Dr N.N. Mahapatra is a B.Sc. (Tech) in Textile Chemistry from UDCT, (now ICT) Mumbai. He also holds a M.Sc. and Doctorate in Applied Chemistry from Utkal University, Orissa. He did his M.B.A from I.M.M, Kolkata. Dr Mahapatra is having 38 years of experience working in Textile and Dyes manufacturing industries in India and abroad in various senior capacities. In the year 2007 he was also awarded C Col FSDC (U.K) and C Text FTI (Manchester). In 2018 he was awarded the Fellowship (FRSC) from Royal Society of Chemistry, UK. He has written 8 books (Textile Dyes & Dyeing, Textile Technology, Textile Processing, Textiles & Environment, Textile Dyes, Sarees of India, Textile Dyeing and Modern Textile Processing). Presently he is working as Business Head (Dyes) Shree Pushkar Chemicals & Fertilisers Ltd, Mumbai.
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
Dr N.N. Mahapatra is a B.Sc. (Tech) in Textile Chemistry from UDCT, (now ICT) Mumbai. He also holds a M.Sc. and Doctorate in Applied Chemistry from Utkal University, Orissa. He did his M.B.A from I.M.M, Kolkata. Dr Mahapatra is having 38 years of experience working in Textile and Dyes manufacturing industries in India and abroad in various senior capacities. In the year 2007 he was also awarded C Col FSDC (U.K) and C Text FTI (Manchester). In 2018 he was awarded the Fellowship (FRSC) from Royal Society of Chemistry, UK. He has written 8 books (Textile Dyes & Dyeing, Textile Technology, Textile Processing, Textiles & Environment, Textile Dyes, Sarees of India, Textile Dyeing and Modern Textile Processing). Presently he is working as Business Head (Dyes) Shree Pushkar Chemicals & Fertilisers Ltd, Mumbai.
