I. Detecting Abnormalities During Equipment Operation
1. Listen for Sound Changes: If the jigger dyeing machine makes a "clunking" sound or periodic abnormal noise when changing direction or accelerating, it may be due to sudden tension changes causing uneven force on the transmission system, indicating tension control imbalance.
2. Check Operation Synchronization: The two fabric rolls should wind smoothly and alternately. If there is "rushing" (one side is taut while the other is slack) or significant lag, it indicates that the tension is not under constant control.
3. Check Control System Feedback: Observe whether the tension value on the frequency converter or PLC panel fluctuates frequently. Under normal circumstances, the fluctuation should be controlled within ±5%. If the value fluctuates wildly, it indicates unstable tension.
4. Feel Mechanical Vibration: If you can clearly feel vibration when holding the machine frame, especially during high-speed operation, it may be due to mechanical resonance caused by tension fluctuations, requiring immediate shutdown and investigation.
II. Finding Clues from Fabric Condition
1. Wavy Wrinkles on the Fabric Surface: If the fabric exhibits transverse "ruffles" or localized looseness during winding, it's usually due to insufficient tension, preventing the material from being fully flattened.
2. Edge Tearing or Stretching Deformation: Lengthening or even breakage of fibers at the fabric edges is a typical sign of excessive tension, especially common in thin or elastic fabrics.
3. Snake-like Deviation (Off-center Tracking): If the fabric continuously shifts to one side during operation, even with a corrective system, it's difficult to correct. This is often caused by uneven tension, leading to an imbalance in force.
4. Uneven Winding Tension: If the finished roll is "tight on the inside and loose on the outside" or has "localized bulges," it indicates that the tension was not kept constant during winding, affecting subsequent processing and storage.
III. Investigating the Root Cause of Dyeing Problems Through Dyeing Quality Analysis
1. If the dyed fabric exhibits color variations, uneven color depth, or inconsistent color intensity between the edges and center, and after ruling out dye and temperature factors, it is highly likely that tension fluctuations are causing inconsistent dyeing times.
2. Frequent wrinkles or weft skew, especially concentrated in a particular pass, indicate uncontrolled tension at that stage, causing fabric deformation.
3. Significant color differences between the beginning and end of the fabric may also be due to improper initial tension settings, leading to unstable fabric speeds at both ends and affecting the uniformity of dyeing.
IV. Auxiliary Judgment Methods
1. Use a tension tester to measure the tension values at each station and compare them to the required process range (e.g., 300–800N). Values exceeding this range are considered abnormal.
2. Observe the fabric surface condition by dyeing a trial white fabric. Physical defects caused by tension are more easily detected without dyeing interference.
3. Check historical power consumption and alarm records. Frequent overload alarms or large fluctuations in motor current are often related to poor tension control.
