PDC sensor for loop control
An ultrasonic sensor for loop control is a device that monitors the position or sag of a material loop in web handling processes. It provides continuous feedback to the system controller, enabling automatic speed adjustments to maintain proper tension and consistent material flow. This guide covers the operating principles, applications, and benefits of ultrasonic loop control sensors.
An ultrasonic sensor for loop control is a device specifically designed to monitor the position or sag of a material loop in web handling processes such as thermoforming, metal stamping, and paper converting. Applying ultrasonic sensors for web tension feedback helps to achieve an efficient, consistent material flow. By monitoring either the sag level of a free-hanging loop between the supply spool and the production station, or a dancer arm's position, the system controller generates on-the-fly speed adjustments to create a precise, repeatable finished product. Keeping the proper tension is essential for maintaining a consistent feed speed and material flow. This consistency ensures the same high quality and end results across the board in the most efficient manner. Ultrasonic sensors are ideal for loop control because they are unaffected by color, surface gloss, or swinging movements of the material loop.
PDC Sensor
The working principle of loop control using ultrasonic sensors is based on non-contact distance measurement. An ultrasonic sensor is positioned above the center of the loop, with the acoustic pulse emitted by the sensor meeting the loop at a perpendicular angle. The device can either continuously monitor the distance to the loop, or signal when defined limits are reached via two switching outputs. The control parameters can be configured quickly and easily using programming buttons or parameterization software. BUS ultrasonic sensors detect sheets on rolls and coils and regulate the correct material feed on the dancer roll according to the sheet sag, ensuring the correct roller drive and that the sheet tension is always perfect. The sensors provide reliable distance measurement regardless of the material size, color, or surface.
Ultrasonic sensors for loop control offer significant advantages over optical sensors. Ultrasonic sensors are ideal when dealing with a dusty environment, clear or different-colored objects, lateral movements of the material loop, and changing target sizes or materials. They give the option of signaling that the loop has reached its high/low limits, with analog versions providing continuous sag monitoring with millimeter precision. The sensors are insensitive to dirt and provide reliable detection of objects with critical surfaces and highly transparent objects. The VERSATEC tension controller is a multi-function automatic tension or process controller that uses the US-2 ultrasonic sensor to measure distance and roll diameter. From the keypad and display, you can control all operating parameters for any operating mode, including tension, distance, dancer position, and loop position.
Loop control sensors are used in various web handling applications. In plastic film wrapping of food trays, a loop in the feeding process is used to manage the tension, preventing broken film, and ensuring the film wrapping process continues smoothly without interruption. To monitor the loop, an ultrasonic sensor is used to detect the clear film and report its status to the controller. The sensor continuously reports the measurement of the loop changes back to the system controller via an analog output, and the controller then uses this information to adjust the speed of the film and maintain a consistent loop and proper film tension. The device can continuously monitor the distance to the loop or signal when defined limits are reached. The sensors are also used in sheet feeding for the coil, detecting sheets on rolls and coils and regulating the correct material feed on the dancer roll.
The benefits of ultrasonic loop control are significant for production efficiency and quality. Reliable material supply control is achieved, with color, surface gloss, or swinging movements of the material loop not affecting performance. The measuring range is quick and easy to set up, with easy mounting and maintenance-free operation. The sensors provide reliable measurement of roll diameter and detection of material break, regardless of the material size, color, or surface. Automatic synchronization prevents cross-talk and ensures reliable measurements. The sensors deliver reliable measurement of distance and roll diameter with high accuracy, enabling precise tension control. By providing dependable, maintenance-free operation, ultrasonic loop control sensors reduce downtime, minimize material waste, and enhance overall productivity in web handling processes.
