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 fiber 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.
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:
a) Increase the Flat speed to 200 to 230 mm/min
b) Increase the Cylinder speed to 480rpm.
c) Wash the card wire with petrol once in every 2 days.
d) Check the bad cards and grind the same.
e) Take card wise trial to identify bad cards and then these cards can be corrected quickly.
2. In addition to these 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:
a) Licker In to feed plate–40 to 50 thou
b) Cylinder to Flat–12/12/10/10/10
5. Roving twist can be increased by one step to reduce short cuts.
6. 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 fiber is insufficient. To overcome this the following measures are suggested:
a) The dyed psf has to be opened by blender more intensely before layering. After layering also give preferably 2 blender toppling.
b) 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.
c) 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:
1. If the type of clearer in autoconer for Dyed yarns is of Capacitor type clearers, then faults can be controlled.
2. 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?
3. 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.
4. Increasing T.M. at S/F and this will help in reducing the cuts. Reduce water and increase OIL content in mixing.
5. 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.
6. 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.
7. 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 fiber dyeing.
TRIAL – 1:
Step-1 – monthly machine cleaning.
Step-2 – before dyeing treat the grey polyester fiber with
Following chemical:
Caustic soda – 2 %
Soda ash – 1 %
Temp – 130ºC
Time – 30 mins
HT drain at 130ºC
Then Hot wash and neutralize
Then start dyeing as usual.
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 fiber do contain Oligomers which has to be removed before dyeing process) at the same time the fiber 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 fiber in the spinning mills we feel Pre dyeing Reduction clearing with 0.5 GPL Afilan OR along with mild dosage of Caustic Soda and Sodium Hydrosulphite (at 90ºC for 5 min) followed by normal post dyeing RC with 2 GPL Afilan OR 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 processes 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
1. Strong dispersing agent – 5 GPL
2. CAUSTIC – 15 GPL
3. HYDROS – 1 GPL
4. Non-Ionic Detergent – 0.5 GPL
Steps:
5. Take one empty carrier in the m/c
6. Add the above chemicals
7. Run at room temp for 10 mins
8. Raise temp to 130ºC and hold temp for 4 hrs, pump running.
9. Stop pump and heating.
10. Leave it for 4-5 hrs
11. Take out the empty carrier
12. Wipe the empty carrier & inside of the dyeing vessel with hessian cloth it will shine like new carrier.
13. Put the other empty carrier
14. Leave it for 4-5 hrs
15. Again start pump raise to 135ºC and hold for 2 hrs.
16. H.T. drain
17. Hot wash at 95ºC with non-ionic detergent -0.25 gpl, for 10 mins.
18. Drain
19. Neutralize at 95ºC with acetic acid -2 gpl.
20. Drain
21. Cold wash
22. Unload empty carrier.
23. 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
1. Strong Dispersing Agent – 2 Gpl
2. Caustic – 5 Gpl
3. Hydros – 0.5 Gpl
4. Non-Ionic Detergent – 0.25 Gpl
Steps:
1. Take one empty carrier in the m/c
2. Add the above chemicals
3. Raise temp to 135ºC.
4. Hold for 1 hr with pump running.
5. H. t. drain
6. Neutralize with acetic acid -1 gpl
7. Hot wash with non-ionic detergent – 0.25 gpl at 90ºC. for 10 mins.
8. Hot drain
9. Cold wash
10. Unload empty carrier.
11. Repeat the same process for the other empty carrier
12. 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
