Knit Fabric Dyeing Process & Time at a glance:
|
PROCESS
NAME
|
PROCESS
TIME
|
|
FILL
WATER
|
3
|
|
RAISE
TEMP TO 50°C
|
2
|
|
INJECT AUXILIARIES
|
3
|
|
FABRIC
LOAD
|
10
|
|
RAISE
TEMP TO 60°C
|
2
|
|
CAUSTIC
DOSING (60°C)
|
9
|
|
RAISE
TEMPERATURE TO 98'C
|
10
|
|
RUN
TIME
|
45
|
|
COOLING
TO 70'C
|
8
|
|
DRAIN
& FILL
|
4
|
|
RAISE
TEMP TO 80°C
|
5
|
|
RUN
TIME
|
10
|
|
COOLING
TO 70'C
|
3
|
|
DRAIN
& FILL
|
4
|
|
RAISE
TEMP TO 50°C
|
2
|
|
INJECT
ACID
|
5
|
|
RUN
TIME
|
15
|
|
CHECK
PH
|
2
|
|
INJECT
ENZYME
|
2
|
|
RUN
TIME
|
40
|
|
INJECT
PK
|
5
|
|
RAISE
TEMP TO 80°C
|
4
|
|
RUN
TIME
|
10
|
|
COOL
TO 70'C
|
2
|
|
CHECK
PEROXIDE EXISTENCE
|
1
|
|
DRAIN
& FILL
|
4
|
|
PH
CHECK (KEEP PH 6 TO 6.5)
|
1
|
|
INJECT LEVELING
|
5
|
|
RUN
TIME
|
10
|
|
SALT
DOSING (50%)
|
20
|
|
COLOR
DOSING(50%) @60'CX20MIN
|
20
|
|
SALT
RUN TIME@60'CX40MIN
|
40
|
|
1ST
SODA(25% OF TOTAL QTY) DOSING@70% @ 60 CX20
|
20
|
|
RUN
TIME
|
5
|
|
2ST
SODA(75% OF TOTAL QTY) DOSING@70% @ 60 CX30
|
30
|
|
CHECK
SHADE (60'CX60MIN)
|
60
|
|
DIRECT
BD & FILL
|
2
|
|
BLOCK
WASH AT 8O'C 5+5
|
10
|
|
DRAIN
& FILL
|
4
|
|
RAISE
TEMP TO 80°C
|
5
|
|
RUN
TIME
|
10
|
|
COOLING
TO 70'C
|
3
|
|
DRAIN
& FILL
|
4
|
|
RAISE
TEMP TO 50'C
|
2
|
|
INJECT
ACID 0.2%
|
3
|
|
RUN
TIME
|
10
|
|
DRAIN
& FILL
|
4
|
|
CHECK
PH (PH MUST BE =7 TO 8)
|
2
|
|
INJECT
CHEMICAL (CROSS COLOR BCSR 1%)
|
5
|
|
RAISE
TEMP 60°C
|
2
|
|
RUN
TIME
|
10
|
|
DRAIN
& FILL
|
4
|
|
COLD
WASH
|
5
|
|
DRAIN
& FILL
|
4
|
|
DOSE
FIXER IF NEEDED
|
6
|
|
RUN
TIME @ 40C
|
10
|
|
DRAIN
& FILL
|
4
|
|
UNLOAD
|
10
|
|
TOTAL
|
9:00
HRS
|
Knit Fabric Dyeing Process: A Comprehensive Overview
The knit fabric dyeing process is a critical step in textile manufacturing, transforming raw or greige fabric into vibrant, colored material suitable for various applications. This article outlines the detailed steps involved in the knit fabric dyeing process, along with the approximate time required for each stage, culminating in a total process time of approximately 9 hours. The process is designed to ensure consistent color application, fabric quality, and durability while adhering to industry standards.
Overview of the Dyeing Process
Dyeing knit fabric involves a series of carefully controlled steps, including water filling, temperature adjustments, chemical injections, and washing cycles. Each step is timed precisely to achieve optimal results, ensuring the fabric is uniformly dyed and free from defects. Below is a detailed breakdown of the process, including the purpose of each step and the time allocated.
Detailed Process Steps
1. Preparation Phase
Fill Water (3 minutes): The dyeing machine is filled with water to create the medium for chemical reactions and dye application.
Raise Temperature to 50°C (2 minutes): The water is heated to 50°C to prepare for the addition of auxiliaries.
Inject Auxiliaries (3 minutes): Auxiliary chemicals, such as wetting agents or stabilizers, are added to enhance dye penetration and fabric preparation.
Fabric Load (10 minutes): The knit fabric is loaded into the dyeing machine, ensuring proper placement for even processing.
2. Initial Treatment Phase
Raise Temperature to 60°C (2 minutes): The temperature is increased to 60°C to facilitate chemical reactions.
Caustic Dosing at 60°C (9 minutes): Caustic soda is dosed to clean the fabric and remove impurities, preparing it for dyeing.
Raise Temperature to 98°C (10 minutes): The temperature is raised to 98°C to optimize the dyeing environment.
Run Time (45 minutes): The fabric is processed at 98°C to ensure thorough cleaning and preparation.
Cooling to 70°C (8 minutes): The temperature is reduced to 70°C to prepare for the next steps.
3. First Washing Cycle
Drain & Fill (4 minutes): The machine is drained and refilled with fresh water.
Raise Temperature to 80°C (5 minutes): The water is heated to 80°C for further processing.
Run Time (10 minutes): The fabric is processed to remove residual chemicals.
Cooling to 70°C (3 minutes): The temperature is lowered to 70°C.
Drain & Fill (4 minutes): The machine is drained and refilled again.
4. Acid and Enzyme Treatment
Raise Temperature to 50°C (2 minutes): The water is heated to 50°C for acid treatment.
Inject Acid (5 minutes): Acid is added to neutralize residual alkalinity and adjust the pH.
Run Time (15 minutes): The fabric is processed to ensure proper pH balance.
Check pH (2 minutes): The pH is verified to ensure it is within the desired range.
Inject Enzyme (2 minutes): Enzymes are added to improve fabric softness and remove surface impurities.
Run Time (40 minutes): The fabric is treated with enzymes for an extended period to enhance texture.
Inject PK (5 minutes): Peroxide killer (PK) is added to neutralize any residual peroxide.
Raise Temperature to 80°C (4 minutes): The temperature is raised for further processing.
Run Time (10 minutes): The fabric is processed to ensure complete peroxide neutralization.
Cool to 70°C (2 minutes): The temperature is lowered.
Check Peroxide Existence (1 minute): A check is performed to confirm no peroxide remains.
Drain & Fill (4 minutes): The machine is drained and refilled.
5. Dyeing Phase
pH Check (Keep pH 6 to 6.5) (1 minute): The pH is verified to ensure it is suitable for dyeing.
Inject Leveling Agent (5 minutes): Leveling agents are added to promote uniform dye uptake.
Run Time (10 minutes): The fabric is processed to ensure even distribution of the leveling agent.
Salt Dosing (50%) (20 minutes): Salt is added to enhance dye exhaustion.
Color Dosing (50%) at 60°C (20 minutes): Dyes are introduced to begin the coloration process.
Salt Run Time at 60°C (40 minutes): The fabric is processed with salt to fix the dye.
1st Soda Dosing (25% of Total Quantity) at 60°C (20 minutes): Soda ash is added to initiate dye fixation.
Run Time (5 minutes): The fabric is processed to ensure dye penetration.
2nd Soda Dosing (75% of Total Quantity) at 60°C (30 minutes): Additional soda ash is added to complete dye fixation.
Check Shade at 60°C (60 minutes): The fabric’s color is checked to ensure it matches the desired shade.
6. Post-Dyeing Washing
Direct BD & Fill (2 minutes): The machine is drained and refilled for washing.
Block Wash at 80°C (5+5 minutes): A block wash is performed to remove excess dye.
Drain & Fill (4 minutes): The machine is drained and refilled.
Raise Temperature to 80°C (5 minutes): The water is heated for further washing.
Run Time (10 minutes): The fabric is washed to remove residual chemicals.
Cooling to 70°C (3 minutes): The temperature is lowered.
Drain & Fill (4 minutes): The machine is drained and refilled.
7. Final Treatment
Raise Temperature to 50°C (2 minutes): The water is heated for acid treatment.
Inject Acid (0.2%) (3 minutes): A small amount of acid is added to adjust pH.
Run Time (10 minutes): The fabric is processed to stabilize the pH.
Drain & Fill (4 minutes): The machine is drained and refilled.
Check pH (pH Must Be 7 to 8) (2 minutes): The pH is verified to ensure neutrality.
Inject Chemical (Cross Color BCSR 1%) (5 minutes): Chemicals are added to enhance color fastness.
Raise Temperature to 60°C (2 minutes): The temperature is raised for chemical processing.
Run Time (10 minutes): The fabric is processed to ensure chemical effectiveness.
Drain & Fill (4 minutes): The machine is drained and refilled.
Cold Wash (5 minutes): A cold wash is performed to remove any remaining chemicals.
Drain & Fill (4 minutes): The machine is drained and refilled.
Dose Fixer if Needed (6 minutes): A fixing agent is added to enhance dye permanence, if required.
Run Time at 40°C (10 minutes): The fabric is processed at a lower temperature to set the fixer.
Drain & Fill (4 minutes): The machine is drained and refilled.
Unload (10 minutes): The dyed fabric is removed from the machine.
Total Process Time
The entire knit fabric dyeing process takes approximately 9 hours (540 minutes). This duration includes all preparation, dyeing, washing, and finishing steps, ensuring the fabric is ready for further processing or use.
Key Considerations
Precision in Timing: Each step’s duration is critical to achieving consistent results. Deviations can affect dye uptake, color uniformity, or fabric quality.
pH Control: Maintaining the correct pH at various stages (e.g., 6–6.5 during dyeing, 7–8 post-treatment) is essential for dye fixation and fabric integrity.
Chemical Usage: Proper dosing of chemicals, such as caustic soda, acid, and enzymes, ensures effective preparation and dyeing while minimizing environmental impact.
Temperature Management: Gradual heating and cooling prevent thermal shock to the fabric, preserving its structure and quality.
Conclusion
The knit fabric dyeing process is a complex but well-orchestrated sequence of steps that transforms raw fabric into vibrant, high-quality material. By adhering to the outlined steps and timings, manufacturers can achieve consistent color, excellent fastness, and superior fabric quality. This process, while time-intensive, is essential for producing textiles that meet industry standards and customer expectations.