I. Pre-Operation Preparation
1. Equipment Inspection: Confirm that the dye bath, fabric winding roller, guide roller, drive unit, and temperature control system are functioning normally, and that the liquid level and temperature sensors are normal.
2. Fabric Preparation: The fabric needs to undergo pretreatment such as desizing, scouring, and bleaching to remove impurities and sizing agents, ensuring a smooth and flat surface to prevent uneven dyeing or creases.
3. Dyeing: The dye must be thoroughly dissolved and stirred in the dyeing tank before being injected into the dyeing cylinder to avoid uneven dyeing leading to pigment deposition on the fabric surface.
II. Dyeing Operation Procedure
1. Fabric Loading and Centering: The fabric is wound flat onto the fabric winding roller, ensuring uniform tension and preventing folds or overlaps.
2. Parameter Setting:
Temperature: Set according to the fiber and dye (e.g., 98-130℃ for polyester disperse dye dyeing). Cover and insulate to ensure uniform temperature within the dyeing cylinder.
Liquor Ratio: The weight ratio of fabric to dye liquor (e.g., 1:3~5 or 1:2.5~3.5).
Time and Number of Passes: Set the dyeing time and the number of forward and reverse padding passes according to the color depth.
3. Start-up and Operation:
Heating Stage: The fabric roll cannot rotate. Add steam to raise the temperature to the set temperature to prevent color difference.
Dyeing Stage: After reaching the temperature, start winding. The fabric is repeatedly dipped and padded in the dye bath. The temperature of the winding roller should be close to the temperature of the dye liquor to avoid affecting the dyeing effect.
Turning and Stopping: Automatic winding dyeing machines can be automatically controlled. For manual operation, pay attention to maintaining proper winding tension.
4. Post-treatment:
Washing: After dyeing, wash once with room temperature water to remove excess dye.
Soaping: Depending on the color depth, soap several times with a soda ash solution at approximately 95℃ to fix the color and improve color fastness. Final Wash: After soaping, wash with 60℃ warm water and then cold water to remove soap residue and auxiliaries.
III. Key Precautions
1. Uniformity: Maintain uniform fabric tension to avoid uneven dyeing or deformation.
2. Safety: During high-temperature and high-pressure operation, take precautions against burns and leaks. Regularly check equipment seals and pressure vessel safety.
3. Maintenance: Regularly clean the dye bath and inspect the dyeing shaft, guide rollers, drive unit, etc., to prevent dye sedimentation or mechanical failures from affecting the dyeing effect.
IV. Common Problem Handling
1. Color Difference: Check the heating rate, fabric roll operation timing, and dye bath temperature uniformity.
2. Creases/Dye Spots: Check the fabric winding flatness and tension uniformity to avoid folding or overlapping.
3. Uneven Dyeing: Check the solubility of chemicals, dye concentration, liquor ratio, and dyeing time.
