WINDING AND UNWINDING LINES
What are winding and unwinding lines?
These systems are essential in many industrial sectors that process web-based materials (e.g. sheet metal, foil, paper, plastic, textile). Their main purpose is to continuously feed or collect material without interrupting the process, while maintaining tension, alignment, and speed in synchronization with other line elements.
Core Functions
Unwinding:
- Material is uncoiled from a roll and fed into downstream processes (e.g. cutting, printing, laminating).
- The key task is maintaining constant tension and centered alignment.
Winding:
- Material is rewound into a roll after processing.
- Critical for accurate edge tracking and even winding density.
Intermediate tension control units (dancer rolls, accumulators):
- Compensate for speed fluctuations and ensure uninterrupted production.
Key Requirements for Efficient Operation
- Speed synchronization between winding/unwinding drives and main processing units.
- Web tension control to prevent tearing or deformation.
- Torque regulation adjusted to roll diameter for smooth winding.
- Edge guiding systems to maintain lateral alignment.
- Automatic reel change systems (turret winders) for minimal downtime.
The Role of Servo Technology in Winding/Unwinding
Servo drives and motors are essential for:
- Integration with vision systems for automatic error correction.
- Precise torque control based on changing roll diameter.
- Synchronization with the main line via EtherCAT, SERCOS, or other real-time fieldbuses.
- Rapid response to changes in speed or direction—especially critical for high-speed lines.
Digitalization and Industry 4.0
Modern winding and unwinding systems are equipped with:
- MES/ERP integration for material tracking, documentation, and analytics.
- Sensors for monitoring tension, temperature, speed, and wear.
- Vision systems for real-time edge monitoring.
- Centralized HMI interfaces for operator control and parameter tracking.