I. Set the initial tension reasonably to avoid a "one-size-fits-all" approach.
The initial tension is the starting point for taper control and directly affects the tightness of the entire roll of material.
It should be set according to the material characteristics: For films (such as PET, EVA), it is recommended to control it at 2~5kg; for fabrics (such as non-woven fabrics), do not exceed 3kg; for sensitive materials (such as optical films, aluminum foil), 1.5~4kg is recommended, combined with closed-loop control.
Recommended calculation formula: Tension (N) = Material width (m) × Setting coefficient (N/m). The specific coefficient needs to be determined based on the tensile strength of the material.
Avoid blindly setting it based on experience: Too high a setting can lead to light transmission patterns or tensile deformation; too low a setting can easily produce bubbles or loose rolls.
II. Scientifically configure the taper coefficient to prevent "tight inside, loose outside" or "tight outside, loose inside" imbalances.
The taper coefficient determines the rate at which tension decreases with increasing roll diameter and is a core parameter for avoiding roll shape defects.
Recommended range: For every 10cm increase in roll diameter, tension decreases by 3%~5%, i.e., straight-line taper control.
Thicker materials require a larger taper: The thicker the material, the more pronounced the interlayer compression; the attenuation rate should be appropriately increased.
Prefer curved taper: In high-precision scenarios, curved taper achieves a smoother tension transition and reduces stress abrupt changes.
III. Ensure a coordinated unwinding and rewinding tension ratio. The rationality of the tension gradient determines the stability of the material during operation.
Basic principle: Unwinding tension should be slightly less than rewinding tension; a recommended ratio is 1:1.05~1.1.
Consequences of disrupting the gradient: If the unwinding tension is too high, the material will be stretched in the opposite direction, leading to wrinkling, misalignment, or even breakage.
IV. Enable the "soft start" function to prevent material breakage during roll changes. The tension shock during roll changes is one of the main causes of film breakage.
Correct Procedure: Activate the "soft start" function to reduce tension to 70% of normal during roll change, then gradually restore it after 2 seconds.
Use the dual-station memory function: Ensure synchronized tension output when switching between old and new rolls to avoid disturbances.
V. Regularly calibrate the roll diameter detection system to ensure accurate feedback. Taper control relies on real-time roll diameter data; inaccurate detection will lead to control failure.
Check the proximity switch installation position and wiring status to ensure there is no looseness or misalignment.
Manually run and verify the roll diameter reading; adjust the sensor position promptly if deviations are found.
VI. Emphasize the monitoring role of the floating roller for dynamic compensation. The floating roller is the first "early warning system" for tension fluctuations.
Installation Position: Should be placed in the pre-compositing station to sense tension changes in real time.
Normal Floating Range: Controlled within ±5mm; parameters need adjustment if it exceeds this range.
Maintenance Requirements: Check the sliding resistance daily to ensure it is between 0.5 and 1N to prevent jamming from affecting feedback accuracy.
VII. Adjust Parameters Based on Material Type Differences, Avoid Universal Parameter Application
Different materials exhibit significantly different sensitivities to tension, necessitating tailored adjustments.
For thin films: Avoid excessive tension causing translucency lines, while preventing insufficient tension from leading to air bubble trapping.
For fabrics: Control tension ≤3kg to prevent fiber indentation or deformation.
For sensitive materials: It is recommended to operate in a stable temperature and humidity environment (23±2℃, RH50%±5%), and use a closed-loop control system.
VIII. Perform Routine Maintenance to Ensure Long-Term System Stability
Good equipment condition is a prerequisite for precise control.
Daily Inspection: Clean the lens of the alignment sensor, check for air leaks in the air pipes, and confirm smooth operation of the floating roller.
Monthly Maintenance: Replace the cooling oil in the magnetic powder brake, calibrate the zero point of the tension sensor, and check the bearing clearance of the alignment roller.
Regular Lubrication: Apply special grease to critical bearings every 500 hours to prevent dry friction from causing a decrease in accuracy.
