Poly Cotton Fabric Dyeing Machine Process

1.1              Poly Cotton Fabric

The yarn produced by mixing Polyester fibre and Cotton fibre with each other during yarn preparation process is known as polyester-cotton blended yarn. Generally, two types of polyester-cotton blended yarn are produced. These are :

1. 65% Polyester + 35% Cotton = PC or TC
2. 40% Polyester + 60% Cotton = CVC (Cheap Value Cotton)

1.2              Pre-treatment Process for Blended Fabric

Pre-treatment process for Polyester-Cotton blended fabric is similar to the 100% Cotton pre-treatment process. Refer to Specification No. 51-301 for detailed pre-treatment process.

1.3              Dyeing Process for Blended Fabric

Two types of dyeing methods are used to dye blended fabric. These are :

1. One-bath Dyeing Method
2. Two-bath Dyeing Method

1.3.1        One-bath Dyeing Method

One-bath dyeing method is a dyeing process whereby, polyester part and cotton part are dyed together in one bath.

1.3.2        Two-bath Dyeing Method

Two-bath dyeing method is a dyeing process whereby, polyester part and cotton part are dyed separately in separate bath.

2.0    Process Requirements

2.1              Equipment used

Three types of Thies machines are used for dyeing process. These are :

• Mini-soft
• Eco-soft
• Luft-roto

2.2              Key Accessories

Key accessories used in dyeing process are :

• Mixing tank
• Machine Tank
• Bohme meter
• p^H meter
• Eye protecting glass
• Hand gloves
• Sewing machine
• Hand lifter for carrying the batch, and
• Gum boot.

2.3              Materials / Chemicals used

Following materials/chemicals are used in the dyeing with reactive dyes process :

• Water
• Steam
• Compressed Air
• Wetting agent
• Detergent
• Sequestering agent
• Acid
• Anti-creasing agent
• Dispersing Agent
• Gluber salt, and
• Soda ash, etc.

3.0    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.
• During production, after reaching at the optimum temperature (above 80⁰C), in case the lid of machine needs to be opened, operator must depressurise the machine and use hand gloves, eye-protecting glass etc. while performing such task for safety.

4.0    Operation Procedure

4.1              Operation Staff

Operation stuffs for Dyeing Process includes :

1. Manager
2. Assistant Manager
3. Production Executive
4. Production Executive
5. Operator
6. Helper

4.2              Machine Set-up

4.2.1        Machine Set-up for Eco-Soft & Mini-Soft Machine

Machine set-up for Poly-Cotton Blended Fabric Dyeing in Eco-Soft & Mini-Soft Machines are as follows :

Machine Group	Fabric Type	G.S.M.	J.P.(Mb)	R.S. (MPM)
ECO-SOFT   & MINI-SOFT	Single Jersey	Up to 140	0500	200
140 ~ 180	0600	190
180 & Above	0800	180
Polo Pique	Up to 160	0600	200
Black Pique	160 ~ 200	0700	180
Popcorn	200 & Above	0900	180

.

4.2.2        Machine Set-up for Luft-Roto Machine

Machine set-up for Poly-Cotton Blended Fabric Dyeing in Luft-Roto Machine is as follows :

Machine Group	Fabric Type	G.S.M.	J.P.(Mb)	R.S. (MPM)
LUFT-ROTO	Single Jersey	Up to 140	0700	200
140 ~ 180	0800	200
180 & Above	1000	190
Polo Pique	Up to 160	0800	190
Black Pique	160 ~ 200	0900	190
Popcorn	200 & Above	1000	180

4.3              Checklist Before Operation

Following are the items to be checked before production :

1. Checking the programme in Beacon Controller
2. Machine set-up
3. Fabric weight
4. Fabric quality
5. Yarn quality
6. Collar design (Tipping / Solid)
7. Rib designs (Normal / Lycra)
8. Chemical availability
9. Power availability
10. Steam availability
11. Water availability
12. Compressed air
13. Manpower availability
14. Fabric stitch is done properly.

4.4              Operation Procedure

4.4.1        One-bath Dyeing Method

Steps of One-bath Dyeing Process

The sequence for one-bath dyeing process is as follows :

1. Take water in bath at required level
2. Add Detergent, Sequestering Agent, Anti-creasing Agent, Dispersing Agent
3. Circulate the fabric for 5 minutes at 50⁰C
4. Add Acetic acid and circulate for 5 minutes at 50⁰C
5. Add Glauber salt and circulate for 5 minutes at 50⁰C
6. Check p^H of the Dye bath
7. Add Polyester Dye solution by linear dosing and circulate the fabric for 10 minutes at 50⁰C
8. Add Cotton Dye solution by linear dosing and circulate the fabric for 10 minutes at 50⁰C
9. Circulate the fabric and raise the temperature at 130⁰C
10. Continue circulating the fabric for 30 ~ 40 minutes at constant temperature (130⁰C)
11. Circulate the fabric and decrease the temperature at 70⁰C
12. Check the shade of Polyester part with approved shade
13. Circulate the fabric and raise the temperature at 82⁰C
14. Continue circulating the fabric for 10 minutes at constant temperature (82⁰C)
15. Add Soda Ash by curve dosing and continue circulating the fabric for 30 ~ 50 minutes at 82⁰C
16. Circulate the fabric and decrease the temperature at 70⁰C
17. Check the shade of Cotton part with approved shade
18. Rinse and Drain
19. Add Acetic acid and circulate for 10 minutes at 60⁰C
20. Drain
21. Add Soaping Chemical and circulate for 10 minutes at 95⁰C
22. Drain
23. Circulate the fabric for 10 minutes at 70⁰C
24. Drain
25. Unload

Graphical Representation of One-bath Dyeing Process

The one-bath dyeing process for poly-cotton blended fabric can be graphically represented as below :

4.4.2        Two-bath Dyeing Method

• Polyester Part Dyeing with Disperse Dye-stuff

Steps of Two-bath Dyeing Method

Steps involved in Two-bath Dyeing Process with Disperse dye-stuff for Polyester Part dyeing are enumerated below :

1. Take water in bath at required level
2. Add Detergent, Sequestering Agent, Anti-creasing Agent, Dispersing Agent
3. Circulate the fabric for 5 minutes at 50⁰C
4. Add Acetic acid and circulate for 5 minutes at 50⁰C
5. Check p^H of the Dye bath
6. Add Dye solution by linear dosing and circulate the fabric for 10 minutes at 50⁰C
7. Circulate the fabric and raise the temperature at 130⁰C
8. Continue circulating the fabric for 30 ~ 40 minutes at constant temperate (130⁰C)
9. Circulate the fabric and decrease the temperature at 60⁰C
10. Check the shade with approved shade
11. Rinse and Drain
12. Add Caustic Soda and circulate for 3 minutes at 70⁰C
13. Add Hydross and raise the temperature at 80⁰C
14. Continue circulating the fabric for 15 minutes at constant temperate (80⁰C)
15. Drain
16. Add Acetic Acid and circulate for 10 minutes at 60⁰C
17. Drain
18. Unload

Graphical Presentation of Two-bath Dyeing Process with Disperse Dyes

The Two-bath Dyeing Process with Disperse dye-stuff for Polyester Part dyeing can be graphically represented as follows :

• Cotton Part Dyeing with Procion Dye-stuff at 82⁰C

Chart

The chart of Electrolytic agent (Glauber Salt) and Fixing agent (Soda ash / Caustic Soda) is given below :

Shade %	G. Salt   (gm/l)	Soda Ash   (gm/l)	Caustic Soda   (gm/l)
Up to 0.30%	30	10	~
0.31% ~ 0.50%	60	10	~
0.51% ~ 1.00%	60	15	~
1.01% ~ 1.50%	70	15	~
1.51% ~ 2.00%	80	15	~
2.01% ~ 2.50%	90	15	~
Above    2.50%	90	20	~

Steps of Two-bath Dyeing Process with Procion Dye-stuff at 82⁰C

The sequence of Two-bath dyeing process for Cotton part dyeing with Procion Dyes at 82⁰C is given below :

1. Take water in bath at required level
2. Add Detergent, Sequestering Agent, Anti-creasing Agent
3. Circulate the fabric for 5 minutes at 50⁰C
4. Add Electrolytic agent (G. Salt) and circulate for 5 minutes at 50⁰C
5. Check p^H and S. G. of the Dye bath
6. Add Dye solution by linear dosing and circulate the fabric for 15 minutes at 50⁰C
7. Circulate the fabric and raise the temperature at 82⁰C
8. Circulate the fabric for 25 minutes at 82⁰C
9. Add Soda Ash solution by curve dosing and circulate the fabric for 30 ~ 50 minutes at 82⁰C
10. Circulate the fabric and decrease the temperature at 60⁰C
11. Check the shade with approved shade
12. Rinse and Drain
13. Add Acetic acid and circulate for 10 minutes at 70⁰C
14. Drain
15. Add Soaping Chemical and circulate for 10 minutes at 95⁰C
16. Drain
17. Circulate the fabric for 10 minutes at 70⁰C
18. Drain
19. Unload

4.5              Product Quality Check

To check the quality of production, following measures are taken :

1. Check the p^H of the bath.
2. Absorbency of the fabric.
3. Hardness of the water.
4. Iron / Impurities contamination of the water.
5. Heating and Cooling system of the machine.
6. Check the shade with customer approved shade.
7. Check the specific gravity of the bath.

4.6              Q.C. Sample Tests

Not applicable.

4.7              Response to Equipment Faults

Following are the response to be taken in case of equipment fault of dyeing machine :

Equipment Fault	Response
Pump Fault	Call Mechanical Maintenance.
Dosing Fault	Self / Call Mechanical / Electrical Maintenance.
Pump Leakage	Call Mechanical Maintenance.
Filling Problem	Call Mechanical / Electrical Maintenance.
Valve Leakage	Call Mechanical Maintenance.
Program Deleting	Call Electrical Maintenance.
Pressure Fluctuation	Self / Call Mechanical / Electrical Maintenance.
Motor Fault	Call Mechanical Maintenance.

4.8              Machine /Area Cleaning

The daily cleaning for machines are described below :

1. Clean chemical chambers by water flow.
2. Clean the floor by water flow.
3. Machine Oiling by oil or greases done by the Mechanical Maintenance Department.

The Maintenance Department performs the preventive maintenance task as per the PM schedule. Refer to Maintenance Specification for details.

5.0    Applicable Forms & Documents

Document Flow

Document flow for the poly-cotton blend fabric dyeing process can be enumerated as below :

Dyeing Department receives the Process Batch Card (F21-101-1) along with the Job Card (F21-101-2) attached to it from the Batch Preparation Section. Process Batch Card is used for fabrics while Job card is used for Collars & Cuffs.

Different specifications (e.g. Lab dip approval #, Fabric weight and quality, Collar quality, shade, etc.) mentioned in the Batch card and Job Card are checked.

Based on the shade and other specification plans for the machines are prepared.

Print-out of the recipe is taken from the DATA-COLOUR computer. The Recipe Card (F51-301-1) 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 Becon Controller.

The Shade Batch Card (F51-301-2) is used to keep track of the dyeing production 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 (R51-301-1) 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’, the Process Batch Card is stamped as “SHADE APPROVED TO FINISH” in Green, on the other hand, if dyeing is ‘NOT OK’, the card is marked as “SHADE APPROVED TO DRY ONLY” in Red. This Process Card is then sent to the Finishing Department.