I. Adjusting the Shelf Balance to Prevent Scratching or Wrinkling
The shelf is a key component in a jigger dyeing machine that supports the fabric's movement. Its flatness directly affects the amount of dye carried by the fabric and the uniformity of dyeing.
1. Ideal State: The height difference between the middle protrusion of the shelf and the two ends should be controlled at 2–3 cm. This prevents scratching that leads to light color and avoids wrinkles caused by excessive flatness.
2. Inspection Method: Use a level or laser rangefinder to measure the height of each point on the shelf.
Observe whether the fabric adheres smoothly and stably during idle operation, without any jumping or shifting.
3. Adjustment Steps: Stop the machine and disconnect the power supply, ensuring safety.
Loosen the shelf fixing bolts and fine-tune the middle support height using shims or adjusting screws.
Perform multiple trial runs and take samples to compare the colors from left to right until ΔE ≤ 1.0.
II. Ensure Uniform Pressure on the Roller Cart for Consistent Liquid Loading The roller cart controls the liquid loading of the fabric through two-roller extrusion. Uneven pressure will directly lead to "edge-center difference."
1. Ideal Configuration: Use a uniform roller cart with pneumatic pressurization at both ends and oil pump supply in the middle (such as the German "Kunster") to ensure consistent rolling pressure.
2. Inspection Method: Weigh the residual rate of the fabric after padding using a balance (take 10 cm² samples from the left, center, and right sides). Calculate the difference:
Residual rate difference ≤ 3% is acceptable;
Difference > 5% requires immediate adjustment.
4. Adjustment Suggestions: Check the sensitivity of the cylinder pressure regulating valve to ensure synchronous pressure on both sides.
For roller carts with difficult-to-level feed troughs, independent pressure regulating valves can be installed on both sides for fine-tuning.
III. Regularly Grind Rolls to Restore Surface Smoothness and Hardness
Wear or uneven hardness on the roll surface can lead to localized pressure imbalance, a hidden cause of edge-to-center defects.
1. Replacement Standards: The hardness of the washing tank rolls should be HS 80±2; the hardness of the feed trough uniform rolls should be HS 70±2; Rolls with obvious dents, cracks, or decreased hardness must be replaced.
2. Grinding Cycle:
Perform a surface inspection every 500 hours of operation;
Schedule professional grinding every 1000 hours to restore roundness and smoothness.
3. Maintenance Points:
After grinding, the pressure must be recalibrated to prevent tension fluctuations caused by diameter changes.
Regularly replace the front and rear rollers to ensure consistent tension across the left, center, and right sides.
