I. Mechanical System Problems
1. Non-parallel or Worn Guide Rollers: Misaligned installation or long-term wear of the fabric winding roller and guide roller can cause uneven fabric stress, leading to tension imbalance.
2. Damaged or Insufficiently Lubricated Bearings: Worn bearings in transmission components create additional resistance, resulting in delayed tension response, especially at high speeds. Poor lubrication accelerates wear between the shaft and bearings, further exacerbating fluctuations.
3. Yarn Bundling or Roller Surface Contamination: Yarn bundles or residual impurities on the stainless steel rollers at the bottom of the cylinder can interfere with normal fabric operation, causing sudden changes in localized tension.
II. Control System Defects
1. Lagging Response in Traditional Open-Loop Control: Open-loop systems using ordinary frequency converters and tension arms lack real-time feedback, resulting in untimely adjustments and difficulty in handling tension fluctuations caused by changes in roll diameter.
2. Aging Tension Sensor or PLC Parameter Drift: Decreased sensor accuracy or improper PID control parameter settings can lead to over- or under-adjustment, amplifying fluctuations.
3. Insufficient Inverter Performance
Ordinary inverters lack precise torque control at low speeds, affecting the stability of low-tension output, especially prone to instability during start-up, shutdown, and reversal.
III. Process and Operational Factors
1. Inappropriate Tension Setting
Excessively high setting values can easily lead to fabric stretching and deformation or even breakage, while too low values can cause loosening and wrinkling. Dynamic adjustment is necessary based on fabric type.
2. Excessive Operating Speed
High-speed operation amplifies tension fluctuations, especially for lightweight and elastic fabrics. It is recommended to control the speed within 15–20 meters per minute.
3. Temperature and Humidity Fluctuations
Changes in workshop temperature and humidity cause fabric shrinkage or elongation, indirectly affecting tension balance. A stable environment must be maintained.
IV. Material and Winding Status
1. Lack of Real-Time Compensation for Roll Diameter Changes
As dyeing progresses, the roll diameter continuously increases. If speed is not dynamically compensated based on encoder data, tension will gradually become unbalanced.
2. Uneven fabric thickness or elasticity differences: High material elasticity, inconsistent thickness, or excessively thick joints can all cause localized tension fluctuations during operation.
3. Uneven seams or guide fabric issues: Excessively wide or uneven seams, or discrepancies between the guide fabric and the dyed material, can lead to uneven stress during winding, causing shaking or shifting.
