Polyester-Cotton (PC) Royal Color Dyeing Process
Introduction
The dyeing of polyester-cotton (PC) blended fabrics requires a precise and systematic approach to achieve vibrant, consistent colors while maintaining fabric quality and meeting industry standards, such as those set by Oekotex. This article outlines a detailed dyeing process for a 50% polyester and 50% cotton fabric with a GSM of 160, dyed in a rich Royal color, as executed on April 3, 2016, for a 5 kg sample order. The process, carried out on Machine No. 5 with a liquor ratio of 1:20 (100 liters), demonstrates best practices for achieving high-quality results in PC fabric dyeing.
Process Overview
Dyeing PC blends is a two-stage process due to the differing chemical properties of polyester and cotton. Polyester requires high-temperature dyeing with disperse dyes, while cotton is dyed at lower temperatures using reactive dyes. The process includes several critical steps: polyester dyeing, reduction clearing, neutralization, semi-bleaching, enzyme treatment, cotton dyeing, soaping, fixing, and finishing. Each stage is carefully controlled to ensure color fastness, uniformity, and fabric integrity.
Detailed Dyeing Procedure
1. Polyester Part Dyeing (135°C x 60 Minutes)
The polyester component is dyed first at a high temperature to ensure proper dye penetration and fixation. The following chemicals and dyes are used:
Acetic Acid (0.5 g/l, 50 g): Adjusts the pH to optimize dye uptake.
Cross Color PLD (0.6 g/l, 60 g): A leveling agent to ensure even dye distribution.
Uniferol Buffer S (1.0 g/l, 100 g): Maintains stable pH throughout the dyeing process.
Taicron Navy Blue HWT (0.5%, 25 g): The disperse dye responsible for the Royal color.
The fabric is processed at 135°C for 60 minutes to allow the dye to penetrate the polyester fibers effectively.
2. Reduction Clearing (90°C x 20 Minutes)
Post-dyeing, reduction clearing removes excess disperse dye from the fabric surface to prevent staining and improve color fastness. The chemicals used are:
Caustic Soda (2.0 g/l, 200 g): Breaks down unfixed dye molecules.
Sodium Hydrosulfite (2.0 g/l, 200 g): Acts as a reducing agent to clear residual dye.
This step is conducted at 90°C for 20 minutes.
3. Neutralization (60°C x 20 Minutes)
Neutralization ensures the fabric is free from residual alkalinity, preparing it for subsequent steps. The chemical used is:
KleeriX NAC Liq Green Acid (1.0 g/l, 100 g): Neutralizes the fabric at 60°C for 20 minutes.
4. Semi-Bleaching (98°C x 45 Minutes)
Semi-bleaching prepares the cotton component for dyeing by removing impurities and enhancing dye uptake. The chemicals used include:
Kappawet BOS (1.0 g/l, 100 g): A wetting agent to improve liquor penetration.
Ron Lube Plus C (0.5 g/l, 50 g): A lubricant to reduce fabric friction.
Kappacom EIS (1.0 g/l, 100 g): A sequestering agent to prevent metal ion interference.
Kappazon H 53-250 (0.4 g/l, 50 g): A stabilizer for peroxide bleaching.
Hydrogen Peroxide (50%) (2.0 g/l, 200 g): The bleaching agent.
Caustic Soda (2.0 g/l, 200 g): Enhances peroxide activity.
This step is performed at 98°C for 45 minutes.
5. Hot Wash (70°C x 10 Minutes)
A hot wash removes residual chemicals from the semi-bleaching process, using:
Kappawet BOS (0.1 g/l, 10 g): Ensures thorough cleaning at 70°C for 10 minutes.
6. Neutralization
Another neutralization step is performed to eliminate residual alkalinity, using:
KleeriX NAC Liq Green Acid (0.5 g/l, 50 g): Neutralizes the fabric.
PK-20 (0.5 g/l, 50 g): Assists in pH stabilization.
7. Enzyme Treatment (55°C x 60 Minutes)
Enzyme treatment removes surface fuzz and improves fabric smoothness, using:
Mega PK2 (0.1%, 5 g): A cellulase enzyme applied at 55°C for 60 minutes.
8. Cotton Part Dyeing (60°C x 60 Minutes)
The cotton component is dyed using reactive dyes to achieve the Royal color, with the following chemicals:
Dekol SNS (1.0 g/l, 10 g): A dispersing agent to ensure even dye application.
Kappacom EIS (0.5 g/l, 50 g): Prevents dye aggregation.
Ron Lube Plus C (0.5 g/l, 50 g): Reduces fabric friction.
Sunfix Blue RS (1.5%, 75 g): The reactive dye for the cotton component.
Glauber's Salt (50 g/l, 2000 g): Promotes dye exhaustion.
Soda Ash (12 g/l, 480 g): Fixes the dye to the cotton fibers.
This step is conducted at 60°C for 60 minutes.
9. Cold Rinse (40°C x 10 Minutes) and Hot Rinse (80°C x 10 Minutes)
Rinsing removes unfixed dyes and chemicals, ensuring clarity of the Royal color.
10. Neutralization (60°C x 15 Minutes)
Neutralization prepares the fabric for soaping, using:
KleeriX NAC Liq Green Acid (0.75 g/l, 75 g): Adjusts pH at 60°C for 15 minutes.
11. Soaping (95°C x 20 Minutes, 2 Cycles)
Soaping removes residual unfixed dyes to enhance color fastness, using:
Setawash SB (1.0 g/l, 100 g): A soaping agent applied at 95°C for 20 minutes, repeated twice.
12. Fixing (40°C x 15 Minutes)
A fixing agent improves the durability of the dye on the cotton fibers, using:
Kappafix GG 100 (3.0 g/l, 300 g): Applied at 40°C for 15 minutes.
13. Finishing by Padding
The final finishing step enhances the fabric’s softness and appearance, using:
KleeriX NAC Liq Green Acid (0.5 g/l, 50 g): Adjusts pH for finishing.
Softsil Nano (20 g/l, 2000 g): A softener for a smooth hand feel.
Key Considerations
The dyeing of PC blended fabrics in a Royal color is a complex but well-structured process that balances the unique requirements of polyester and cotton. By following the outlined steps—polyester dyeing, reduction clearing, semi-bleaching, enzyme treatment, cotton dyeing, and finishing—textile manufacturers can achieve vibrant, durable, and high-quality results. This process, as demonstrated in the sample order, showcases the precision and expertise required to meet customer expectations and industry standards.
| Date | 03-Apr-16 | Customer | Oekotex CII | Load | 50% | ||
| Color | Royal | Order # | Sample | Reference | Swatch | ||
| Fabric | Polyester/Cotton (PC) | GSM | 160 | Machine | No.5 | ||
| Quantity | 5 Kg | Liquor Ratio | 1:20 | Volume | 100 | ||
| Polyester Part Dyeing 135 C x 60 Mins | |||||||
| Chemicals | Dosage | Quantity in grams | |||||
| Acetic Acid | 0.50 g/l | 50 | |||||
| Cross Color PLD | 0.60 g/l | 60 | |||||
| Uniferol Buffer S | 1.0 g/l | 100 | |||||
| Taicron NAVY BLUE HWT | 0.500% | 25 | |||||
| Reduction Clearing 90 C x 20 Mins | |||||||
| CAUSTIC SODA | 2.0 g/l | 200 | |||||
| Sodium Hydrose | 2.0 g/l | 200 | |||||
| Neutralization 60 x20 Mins | |||||||
| KLEERIX NAC LIQ GREEN Acid | 1.0 g/l | 100 | |||||
| Semi- Bleaching 98 C X 45 Mins | |||||||
| Kappawet BOS | 1.0 g/l | 100 | |||||
| RON LUBE PLUS C | 0.5 g/l | 50 | |||||
| KAPPACOM EIS | 1.0 g/l | 100 | |||||
| Kappazon H 53-250 | 0.40 g/l | 50 | |||||
| Hydrogen Peroxide ( 50%) | 2.0 g/l | 200 | |||||
| Caustic Soda | 2.0 g/l | 200 | |||||
| Hot Wash 70 C X 10 Mins | |||||||
| Kappawet BOS | 0.10 g/l | 10 | |||||
| Neutralization | |||||||
| KLEERIX NAC LIQ GREEN Acid | 0.5g/l | 50 | |||||
| PK-20 | 0.5g/l | 50 | |||||
| Enzyme Treatment 55C X 60 Mins | |||||||
| MEGA PK2 | 0.100% | 5 | |||||
| Cotton Part Dyeing 60 C X 60 Mins | |||||||
| Dekol SNS | 1.0 g/l | 10 | |||||
| KAPPACOM EIS | 0.5 g/l | 50 | |||||
| RON LUBE PLUS C | 0.5 g/l | 50 | |||||
| Sunfix Blue RS | 1.50% | 75 | |||||
| Glauber's Salt | 50 g/l | 2000 | |||||
| Soda Ash | 12g/l | 480 | |||||
| Cold Rinse 40 X 10 Mins, Hot Rinse 80 C X 10 Mins | |||||||
| Neutralization 60 C X 15Mins | |||||||
| KLEERIX NAC LIQ GREEN Acid | 0.75g/l | 75 | |||||
| Soaping 95 C X 20 Mins (2X) | |||||||
| Setawash SB | 1.0 g/l | 100 | |||||
| Fixing 40 C x 15Mins | |||||||
| Kappafix GG 100 | 3.0 g/l | 300 | |||||
| Finishing by Padding | |||||||
| KLEERIX NAC LIQ GREEN Acid | 0.5 g/l | 50 | |||||
| Softsil Nano | 20 g/l | 2000 | |||||