I. Standardize operating procedures and eliminate human error.
1. Strictly adhere to standard operating procedures (SOPs). Before each start-up, confirm that the fabric loading is within the equipment's rated range (usually 60%~80% of the cylinder's effective volume) to avoid overload, which can lead to poor circulation or tangling.
2. Properly control heating and cooling rates. The recommended heating rate is 1~2℃/min, and the cooling rate should not exceed 2.5℃/min to prevent dye agglomeration due to sudden temperature changes or uneven fabric thermal shrinkage.
3. Correctly add dyes and auxiliaries. Dyes must be fully dissolved and filtered before addition to avoid clumping and nozzle blockage. When mixing colors, select dyes with similar dyeing rates to reduce the risk of uneven color.
II. Optimize Process Parameters to Ensure Dyeing Stability
1. Precisely Set Liquor Ratio and Circulation Pressure
Adjust the liquor ratio according to fabric type: 8:1 is recommended for overflow systems, and as low as 4:1~6:1 for jet systems, to save water and improve dye penetration.
2. Match Nozzles to Fabric Characteristics
Use small-diameter nozzles (e.g., 50mm) for thin fabrics and large-diameter nozzles for heavy fabrics to ensure uniform fabric speed and prevent conveying delays or knots.
3. Strengthen Dye Liquor Circulation Monitoring
After starting the main pump, allow the fabric to run smoothly for 3~5 minutes before adding material to ensure stable fabric operation; monitor the circulation pressure in real time (usually 0.1~0.3MPa), and investigate immediately if abnormalities occur.
III. Strengthen Equipment Maintenance to Eliminate Potential Hazards
1. Clean Key Components Every Shift
After dyeing, promptly clean the dye tank, nozzles, filters, and pipelines to prevent the accumulation of oligomers or fiber debris that can cause blockages.
2. Regularly inspect the sealing and transmission system. Check the cylinder door seals weekly for aging, and lubricate the main pump bearings, guide rollers, and other moving parts monthly to ensure smooth operation.
3. Periodic deep maintenance. Disassemble and clean the heat exchanger every 3-6 months to remove scale and improve heat exchange efficiency; replace wear parts such as filters and nozzle bushings to prevent sudden malfunctions.
IV. Establish a preventative management system.
1. Thoroughly clean the dyeing tank before changing from dark to light colors. When changing from dark to light colors or whitening agents, use caustic soda and detergent for high-temperature scrubbing (130℃, 60-90 minutes) to prevent color contamination.
2. Avoid mixing different fibers to prevent oligomer deposition. When producing polyester fabrics, clean the filter regularly (once per shift) to reduce the precipitation of cyclic oligomers that adhere to the fabric surface during cooling.
3. Establish equipment operation records. Record the dyeing process parameters, malfunctions, and handling measures for each dyeing process to facilitate traceability analysis and continuous optimization.
