Prepare the recipe of Disperse Dyeing or Polyester Dyeing for the shades given by customer. Number of trials per shade depends on the loading capacity of the machine to be used and the numbers of shades received. aaa
Accurately weigh the dyes (+/-2% of the required weight) and dissolve in an accurately measured volume of water. Volumetric flask is preferable for water measurement. Dye solutions should be stored in erlenmeyer flask for easily shaking up before use because disperse dyes settled at the bottom after some time standing. It is to be stored at room temperature and discarded after two days. The solution concentration should be appropriate for the depth of shade to avoid dispensing small volume. See table for cotton on dye solution preparation.
Check and weigh whether the substrate sample is within +/- 2%.
Pipette the required volume of dyestuff accurately also using the electronic dispensing pipette. If graduated glass pipettes is to be used avoid using chipped pipettes or pipettes with broken tips and select pipette with correct capacity. For example :
Pipette
Capacity
Optimum Working Range
0.2 ml
0.10 – 0.20 ml
0.5 ml
0.201 – 0.50 ml
1.0 ml
0.51 – 1.0 ml
2.0 ml
1.01 – 2.0 ml
5.0 ml
2.01 – 5.0 ml
10.0 ml
5.01 – 10.0 ml
20.0 ml
10.01—20.0 ml
Add auxiliaries and chemicals to be used like in bulk.
Calculate the quantity of water required, allowing for dye and chemical additions and add to the Polyester Dyeing beakers.
Add the rolled up substrate (avoid folding/creasing), seal the dyeing beakers and vigorously shake the vessel to ensure even liquor uptake.
Place the Polyester Dyeing vessel into the dyeing machine at the set Disperse Dyeing temperature.
At the end of the dyeing program remove the beakers individually and wash the samples in cold running water for 2 minutes.
Separate the medium and dark shade samples and load again in the Polyester Dyeing machine for reduction clearing process. See recipe for reduction clearing.
After reduction clearing program is finished then the samples are washed with cold running water then acidify with 0.5 g/l acetic at 40 degrees for 10 minutes, and unload, wash with cold water.
The samples are then burn out or dissolved in 70% prepared sulphuric acid to dissolved the cotton part and assessed the polyester part remained after drying. If polyester part samples is okay with the customer standard then cotton part can be start to match. This is in case of double dyeing or two-part Disperse Dyeing.
One Bath Dyeing of PES/Cotton
Follow procedure i – vii of disperse dyeing. At procedure iv, selected reactive dyes will be pipetted also and added with disperse dyes already pipetted.
On procedure v, salt will be also added together with dispersing chemicals and auxiliaries .
Water for dyeing has sequesterant and lubricant agent already so this will be the one to be added to the dyeing vessel as the calculated water needed in procedure vi
The dyeing beakers will be loaded at the new select program when all the needed dye, chemicals, fabrics and water are input. The dyeing temperature and time will be for polyester part dyeing first then after it will be cool down to the required cotton dyeing temperature.
The machine will run for 10 minutes at the cotton dyeing temperature then all dyeing beakers will be unload placing on the beaker rack individually for alkali addition. Alkali and acid must not be added together on this one bath dyeing at the start because disperse dyeing is done on acidic medium. The pH must be check after alkali addition to see if it is on the range of 10.5-11 (cotton part dyeing pH required).
Load the dyeing beakers after alkali addition then continue the new select program , that is cotton part dyeing.
When dyeing program is complete, proceed for after treatment of reactive dyeing. This new select program is not applicable for dark shades which required reduction clearing because this need only after treatment like cotton part dyeing.
Reduction clearing chemicals will strip or reduce to a big % the cotton dyes from the fabric.
Conclusion
Dry the samples of Disperse Dyeing or Polyester Dyeing, condition and assess the shade. If shade matches with the standard then samples will be filed for approval but if not then it needs to be re-matched.
The sample dyeing machine are always clean inside with wet fabric to remove dyes spillage and dry immediately, keeping it shiny. Housekeeping and cleaning of the area is maintained to have smooth flow of work and to be safe. Sample beakers are always wash after dyeing to remove dyes stains. aaa sss
Response To Equipment Faults
In case of any machine and equipment faults the Maintenance department is immediately notified with corresponding reports to take prompt corrective action
Product Quality Check
New dyes and chemicals are tested for
quality by physical appearance and application evaluation such as:
Dye self shade comparison with other brands
Dye behaviour with other dye combination and chemicals
pH
Saturation point
Solubility
Color
Odour
Appearance
Checklist Before Lab Dyeing
Availability of Fabrics to be Used
To proceed for lab. dyeing immediately standard fabrics which are always requested by buyers were already prepared and stocked them . It was pre-treated accordingly, including them in dyeing pre-treatment to have same effect in lab. Pre-treatment are as follows:
Scouring :
boiling off process with detergent and alkali (soda ash/caustic). Usually done for shades to be dyed like dull red, maroon, navy and black.
Semi-bleaching :
pre-treatment with hydrogen peroxide and other chemicals like caustic/soda ash, detergent, sequesterant and peroxide stabilizer. This is applicable for bright shades, pale/light shades and sensitive shades.
Availability of dyes and chemicals, and water
Ensure all dyes, chemicals and water are available with required quantity.
Conclusion
Ensure Sample Deing Machine is in proper condition and all required accessories are available with required quantity.
Reactive Dyeing – Prepare recipe according to same dyeing condition(temperature, time, process aaa
Check weigh the substrate sample to within +/- 2%
Accurately weigh the dye (+/- 2% of the required weight) and dissolve in an accurately volume of water using volumetric flask. The correct level being achieved after dye dissolution. Dye solutions should be stored in stoppered flasks at room temperature and discarded after 2 days (maximum). The solution should be appropriate for the depth of shade to avoid dispensing small volumes. For example
Add the required volume of dyestuff accurately (preferably via electronic dispensing pipette) Electronic Dispensing Pipettes (EDPs) have a capacity of 10mls. Where larger volumes are required multiple additions will be required.
Calculate the quantity of water required, allowing for dye and chemical additions, and add to the dyeing vessel.
Add the required amount of electrolyte and ensure it is thoroughly mixed/dissolved.
Add the rolled up substrate (avoid folding/creasing) , seal the dyeing vessel and vigorously shake the vessel to ensure even liquor uptake.
Place the dyeing vessel into the dyeing machine at the pre-set starting temperature.
Pre-program the dyeing machine to reproduce the bulk dyeing profile. Use Isothermal to represent standard, isothermal and rapid process. If using migration in bulk, the same migration profile should be used in the laboratory.
At the point of alkali addition, stop the machine and remove the dyeing vessels individually. Accurately add the dilute solution of alkali. Seal the vessel and shake vigorously before placing back in the dyeing machine.
Run at the set fixation temperature for the prescribed fixation time.
If recipe have caustic soda addition aside from soda ash, then the machine will just be set for soda ash fixation, and stop the machine for caustic addition. It will be accurately added as diluted solution also. The vessel will be sealed and shake vigorously before placing back in the dyeing machine. Run at the set fixation time mostly 40 minutes.
At the end of the dyeing stage remove the dyeing vessels from the machine and rinse the dyed samples individually in hot running water for 2 minutes. The dyed samples should then be acidified at 40 degrees for 10 minutes then cold rinse. Soaping with anionic detergent followed at a liquor ratio of 1 : 30 for 15 minutes at the boil. After soaping rinse in warm water for 2 minutes, then squeeze and dry in finishing dryer to have similar drying temperature as in production.
Deep dyeing machine Deep dyeing is the process by which the is dyed partially. In this process dyeing is completed by sinking the garments in the dye bath. This gives the garments a unique look. Influencing Factors for Dyeing During dyeing with reactive dyes, following important factors are to be considered
The pH of the bath Pretreatment Process
The temperature of bath
The concentration of the electrolyte
The time of dyeing
The liquor ratio
Process Requirements Equipment used Special type of machine is used for deep dyeing program. It consist hanger where the garment are hanged. Key Accessories Key accessories used in dyeing with reactive dyes are : • Mixing tank • Machine Tank • pH meter • Hanger Pretreatment Process • Eye protecting glass • Hand gloves • Hand lifter for carrying the batch, and • Gum boot. Materials / Chemicals used Following materials/chemicals are used in the dyeing with reactive dyes process: • Water • Steam • Compressed Air • Wetting agent • Sequestering agent • Acid • Anti-creasing agent • Glauber salt, • Soda ash, etc.
Safety: In order to ensure floor and personnel safety floor personnel are instructed to follow the safety guidelines given below: • Smoking is strictly prohibited in the factory premises. • Put on the safety masks while mixing or transferring alkali and acid. • Be cautious while handling caustic soda and use hand gloves, eye protecting glass for safety. • During production, after reaching at the optimum temperature (above 800C), operator must use hand gloves, eye-protecting glass etc. while performing such task for safety.
4 Operation Procedure
4.1 Operation Staff
Operation stuffs for Dyeing process include:
Factory Manager
Assistant Manager
Sr. Production Officer
Production Officer
Supervisor
Operator
Helper
4.2 Checklist before Operation
Following are the items to be checked before production:
a) Checking the programme in Beacon Controller
b) Machine set-up
c) Garment weight
d) Garment quality
e) Dyes availability
f) Chemical availability
g) Power availability
h) Steam availability
i) Water availability
j) Compressed air
k) Manpower availability
l) Garment stitch is done properly
4.3 Operation Procedure
The sequence for deep dyeing process with Starfix dyes is as follows:
Hot wash the garments
Hang the garments in the hanger
Take water bath in deep dye machine at required level
Add dyes solution in the water bath
Add G.salt and soda ash
Mix them well
Hang the garments in the machine in the machine hanger
Now gradually sink the garments by manual operated up down switch
The lower portion of the garments will be deeper then the upper portion
Check the shade with approved shade
Rinse and Drain
Unload
4.4 Machine /Area Cleaning
The daily cleaning for machines are described below:
a) Clean chemical chambers by water flow.
b) Clean the floor by water flow.
c) Machine Oiling by oil or greases done by the Mechanical Maintenance Department.
5 Applicable Forms & Documents
5.1 Forms & Documents Used
Following forms and reports are used for dyeing process:
Process Batch Card
Process Recipe Card
Production Report Format
Document Flow
Document flow for the pre-treatment process can be enumerated as below:
Dyeing Department receives the Process Batch Card attached to it from the Batch Preparation Section.
Based on the shade and other specification plans for the machines are prepared.
Print-out of the recipe is taken from the computer. The Recipe Card is used as an internal document to keep record of dyeing for a particular batch.
Availability of chemicals and dyestuff is checked and program is put in the Bacon Controller.
The recipe shit Card is used to keep track of the dyeing procedure continuity. Production Officer fills out different areas of the form. This is an internal document of the dyeing department.
The Operator fills out the Production Report and it is sent to the Planning department. This report contains information like the Quantity produced, Machine wise production, Amount of re-process, Machine utility percentage (%) and shift wise production.
Upon completion of dyeing for a particular batch, if the dyeing is ‘OK’, then this garment is sent to the Finishing Department along with batch card.
The conditions of exhaust processing on a jet
are simulated.
The capacity of a penetration accelerant to
destroy foam or control foaming during a dyeing cycle is assessed by measuring
the foam level in a Mathis laboratory overflow jet.
Apparatus
mathis lab dryer overflow jet JFO with Datex
200 control
( 70
mm jet )
Liquor circulation
100 l/min.
Fabric speed
20 m/min.
Textile material
750 g Tersuisse tricot ( item No. 5-4204 )
Dyes
0.15% Terasil Yellow 4G
0.40% Terasil Red 5G
0.15% Terasil Navy BGLN 200%
(dispersed in 500 ml de-ionized water )
Chemicals
1.35 g/l Univadin DIF
2.0
g/l ammonium sulphate
(dissolved in 500 ml de-ionized water)
load fabric into jet
add 6 lt. water and heat to 60°C
pump liquor into preparation tank
add dissolved chemicals, dyes and test
product to preparation tank
adjust to pH 4 – 4.5
run liquor back into dyeing machine
bulk liquor to 7.5 lt.
Dyeing
(programme No. 2)
raise temperature at 1.5°C/min to 130°C and
hold it there for 30 min.
note foam level at intervals of 10°C and
enter in the separate table ( enclosure 1 )
cool at 1.5°C/min to 80°C
then rinse cold
Assessment
mathis lab dryer -The foam generated is measured in cm, and the results are plotted in the form of a graph.
Procedure for starting the FOAMY
o Switch on FOAMY
Press “ON/OFF” button of B. Display of A flashes !
o Briefly press key "0" of A --> flashing stops --> A ready for program selection
o Program selection
Hold down key “0” of A. In display of A “00” or a figure appears above Step. Press the key “+” or “-” of A at the same time to select the program.
In the case of the antifoams it is program 01. —> enclosure 3
o Choice of liquor flow rate
Press key “Const” of B , then button “liquor flow rate control” of B. “Liquor flow rate” is activated in the display of B.
Set the desired value by pressing the key “+” or “-” of B .
In the case of the antifoams this is 1.6 lt/min.
o Preparation of program start
Press key “+” or “-” of A until the number “01” appears in the A display in the Step field.
The program is now ready to start.
o Textile material
Load the textile material loosely on the support and insert it into the cylinder of the FOAMY. Close cylinder.
o Foaming medium
Pour 1000 ml foaming medium into the foam generating cylinder. Close cylinder.
o Starting the program
Actuate the “Press” key of B. The system is pressurized. At 0.9 bar actuate the “Press” key again to stop the pressure increasing further.
o Press the "Pump" key of B. Liquor circulation starts.
Wait until the rate of liquor flow has stabilized at about 1.6 lt/min.
o Press key "S" of A .The time/temperature program starts running.
The entries and the current temperature, time and program step status now alternately appear in the A display.
o When the layer of foam in the foam generation cylinder has reached a thickness of 30 cm, meter in the required amount of antifoam via the sluice.
o Foam thickness in cm: note and record with reference to table "Foam measurement FOAMY ". --> enclosure 4
o On completion of testing, drain off liquor, remove material and clean FOAMY by a separate program.
Fabric carts for handling coton , polyester, linen, velvet
Case Study
Sunday, April
came. Our director sir saw the portrait & window display. He liked it &
appreciated us. And finally, Victor came; we all welcomed him by giving &
throwing flowers. When he was going upstairs, He showed him the portrait. He
liked that so much that he started taking photos. After visiting all the floors
we had a meeting and the chief guest was victor Rawlinson. After the meeting we
were doing our daily grinds. Suddenly sir called our team coordinator& us.
We met victor again. He appreciated us for our extra ordinary works. This
influenced us to go for the next step & show our creativity.
Victor left.
sir came to us & appreciated us again & shook hands.
What we visualized & designed, everything took its own shape & it was amazing to watch that & have that feeling.
For most drying processes of fabrics, it is not desirable that all water evaporates. For textiles, the optimum moisture level is their natural moisture level (e.g. 7% for cotton). Drying beyond the natural moisture level takes extra time and energy and besides, it tends to reduce the quality of the fabric.
In practice, evidence shows that 22% to 80% of the heat consumption in tenters and dryers is due to the heating of fresh air. Substantial energy savings can be achieved by reducing the quantity of drying air, e.g., by adjusting the flaps in the air outlets or controlling the frequency of the exhaust ventilator. The optimum quantity of drying air is determined and/or controlled according to the moisture level of the air and/or the pressure level in the machine.
An important point is that, in case the air supply to the burner is reduced, there is a danger that too much carbon monoxide is produced. Therefore, the air supply to the burners cannot be reduced indefinitely. In those cases, it is preferable to adjust or replace the burners. In all this, it is important to make sure that the air flow is sufficiently strong for removing dirt and moisture.
In case making adjustments to the air flow proves impossible, controlling the moisture level of the dried fabric can still save energy. By monitoring the moisture level of the dried fabric directly or indirectly, the drying time and the conveyor belt speed can be adjusted.
Jet Dyeing Machines: M/C process capacity width 1 Singeing 150 m/min. 1200-3200 mm. 2 Desizing 150 m/min. 1200-3200 mm 3 Scouring 150 m/min. 1200-3200 mm 4 Bleaching 150 m/min. 1200-3200 mm 5 mercerization 150 m/min. 1200-3200 mm
