From tension control to automatic web correction: a key technological breakthrough for film slitting machines
Posted by sebrina
from the Business category at
07 Jul 2025 03:47:53 am.
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1. High-precision tension control technology
Technical challenges
During film slitting, tension fluctuations can cause the material to stretch, wrinkle or break, especially at high speeds (e.g. above 600 m/min), which is difficult for traditional mechanical tension control to meet.
Breakthrough
• Closed-loop PID control algorithm: through real-time feedback (such as tension sensor + encoder) to dynamically adjust the torque of the unwinding/winding motor, the accuracy can reach within ±0.5%.
• Adaptive tension model: Automatically adjusts control parameters based on material properties (e.g., elastic modulus of PET, BOPP) and process parameters (speed, width) to avoid overshoot or oscillation.
• Segment tension control: The slitting area adopts a "taper tension" strategy (e.g. the winding tension decreases by 10%-15% from the inside to the outside) to prevent core deformation.
Case
The slitting machine adopts multi-motor independent drive + digital tension controller to achieve tension fluctuation < 1N, suitable for ultra-thin lithium battery separator (6μm) slitting.
2. Automatic Web Guiding System (EPC)
Technical challenges
Film mistracking (± 1 mm can lead to rejection) needs to respond in milliseconds, and traditional photoelectric sensors are susceptible to ambient light interference.
Breakthrough
• Edge Detection Upgrades:
◦ Linear CCD+IR light source: resolution up to 0.1mm, anti-ambient light interference (e.g. 920nm wavelength of LED light source).
◦ AI image processing: Convolutional neural network (CNN) identifies film edge defects (burrs, tears) and triggers alarms synchronously.
• Actuator Optimization:
◦ Linear motor tracking: response time < 10ms, 5 times faster than the cylinder, and the repeatability of positioning ± 0.05mm.
◦ Predictive Tracking: Predict deviation trends (such as material inhomogeneity) based on historical data, and adjust the guide roller angle in advance.
Case
The "double closed-loop EPC system" (photoelectric detection + air flotation correction roller) is adopted, and the deviation correction accuracy is ±0.3mm, which is used for optical film slitting.
3. Multi-technology collaborative integration
System-level innovation
• Tension-Guiding Coupling Control: Through coupling algorithms (e.g., fuzzy PID), the local tension is fine-tuned synchronously during correction to avoid edge stretching.
• Digital twin simulation: virtual commissioning to verify parameters in advance (e.g. vibration suppression scheme when the slitting speed is increased from 300 m/min to 800 m/min).
• IoT platform: real-time monitoring of OEE (Overall Equipment Effectiveness) and predictive maintenance (such as early warning of the life of the guiding cylinder).
4. Future technology direction
• Magnetic levitation guide rollers: zero-friction deviation correction, suitable for nanoscale thin films (such as graphene conductive films).
• Quantum tension sensing: Tension measurement based on the principle of quantum entanglement, with a theoretical accuracy of up to 0.01N.
• Fully autonomous AI control: "Self-evolving" process parameter optimization through reinforcement learning (RL).
summary
The technological breakthrough of the film slitting machine is essentially an upgrade of the "perception-decision-execution" chain:
High-precision sensing (e.g. CCD/fiber tension detection→ Intelligent algorithms (adaptive PID/AI prediction), → highly dynamic execution (direct drive motor/pneumatic servo). In the future, with the explosion of demand for flexible electronics and new energy films, slitting technology will further evolve to "ultra-precision + unmanned".
Tags: film slitting machine
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