I. No-load test run
1. Equipment inspection:
Confirm that the nozzle gap is uniform to avoid inconsistencies between fabric speed and dyeing volume.
Check the functions of the main pump, dye addition pump, fabric delivery wheel, and other buttons.
Set the program (such as temperature curve and time signal) to ensure it meets the requirements of the processed fabric.
2. Material preparation and feeding:
First, pulp and stir the disperse dye with cold water for 20-30 minutes, then dilute it with 40-45℃ warm water.
Dissolve the dispersant and ammonium sulfate in warm water and stir well, dissolving as needed.
Filter the materials during feeding; dissolve small particles again and filter.
3. Temperature and pressure control:
Add acetic acid at around 40℃ to adjust the pH to 5-6, then add the dye and run for 10 minutes.
Control the heating rate at 1℃/min to avoid uneven dyeing due to excessive speed.
The liquor ratio is typically 1:8-1:20, adjusted according to the equipment model and structure.
II. Load Trial Run
1. Fabric Feeding and Material Addition:
Before feeding the fabric, check the vat opening for potential snagging. Ensure the feeding force is appropriate.
Dissolve and add dyes, chemicals, and auxiliaries, avoiding splashing that could cause injury.
Dyeing grey fabrics in the same vat simultaneously is strictly prohibited.
2. Heating and Pressurization:
When the machine is running, the dye liquor should be above the lowest point inside the fabric storage tank. Cooling water must be drained before heating.
If the fabric becomes sluggish during operation, take immediate action, but do not open the vat lid.
3. Dyeing Process:
When the dye concentration in the vat reaches a certain level, the dye begins to flow through the overflow trough into the next vat, ensuring uniform dye distribution.
Adjust the dye concentration and pH value in the vat according to the material and color requirements of the dye.
III. Safety and Maintenance
1. Safe Operation:
Close the machine cover before dyeing and observe the fabric's movement inside the machine through the glass viewing window.
Check all parts of the machine for abnormal sounds and phenomena.
2. Equipment Maintenance:
Clean the dyeing vat and filter screen regularly to prevent dye buildup.
Strengthen the cleaning and rinsing of the dyeing vat to prevent dye buildup.
IV. Common Problem Handling
1. Color Variation and Difference:
Dye not fully dissolved, excessively rapid heating, residual auxiliaries on the fabric, or uneven pH.
Solution: Pulp the dye with cold water, dissolve it in warm water, and add the following order: acid → auxiliaries → dye. Control the heating rate.
2. Wrinkles (Chicken Claw Marks):
Excessively rapid cooling, excessively long stacking time, improper nozzle design.
Solution: Allow the fabric to cool naturally (2℃/min to below 80℃), add an anti-wrinkle agent (0.5g/L), and avoid centrifugal dehydration.
3. Color Spots and Stains:
Incomplete dye dissolution, sizing or oil stains on the fabric, poor water quality.
Solution: Filter the dye before use, strengthen pretreatment, and use low-foaming additives.
