With COMBIVERT the perfect fiber
Application Trützschler Fiber Line - Even in the early years of commercial production of synthetic fibers made of polyester, polyamide and polypropylene Trützschler Nonwovens & Man-Made Fibers played a major role in the market. Over the decades the company (formerly Fleissner) in Egelsbach delivered more than 300 plants, so-called fiber production lines, to customers throughout the world. The new design of the plant Fiber Line (= fiber production line) included the task for a new drive concept to optimize the process technology.
A controlled power supply compensates the variations in instable public power supplies. The installed KEB COMBIVERT F5-AFE (active front end) supplies the entire plant with an adjustable, controlled DC link voltage – that is the basis for reliable, reproducible process sequences in the production engineering.
In the DC-Bus individually protected drives optimize the efficiency by exchanging energy of motor / generator-driven axes and enable an optimal adaptation of the processing stages. The great number of drives makes it necessary, to fit these with specially developed DC- filters and in case of motor cables up to 120 m with motor chokes on the output side to comply with the EMC requirements.
For the optimal control of synchronous and asynchronous motors drive controls KEB COMBIVERT F5 in the “sensorless controlled” design SCL and ASCL are used, which provide a safe torque off (Safe Torque Off-STO). The safety function complies with the requirements according to the performance level e (ISO13849-1) and SIL 3 (IEC 61508 and IEC 62061).
To minimize the waste heat in the control cabinet, the KEB COMBIVERT F5-AFE (active front end) was designed with water-cooling.
In emergency-stop operation the resulting braking energy is refed into the mains supply. In case of a simultaneous power failure braking resistors take over the energy absorption.
All KEB COMBIVERT F5 drive controls communicate with the primary control level including remote maintenance serially via Profinet.
In previous plants godet drives were realized with an asynchronous motor and a gear box. Thus the stretching of individual godets was determined by the gear ratio.
The innovation of the new plant lies in a multi-stage, compact stretching unit with directly driven godets. It is accomplished with multi-pole permanent-magnet excited synchronous motors (high-torque-motors) whose speed and torque is controlled by KEB COMBIVERT F5-SCL drive controls in encoderless operation.
This solution offers even several advantages. The compact module replaces several stretching units, which significantly reduces the overall length of the fiber line. Speed and torque are easy to monitor and as a result increase the protection of the plant. The process optimization is the most important point: since speed and stretching ratio are variably adjustable among the godets, the danger of thread entanglement and breakage is reduced.
The technological implementation and all steps of commissioning this fiber line were accompanied by the KEB Service Department as part of a service from the factory in Egelsbach to the final site in India.
© Trützschler Nonwovens & Man-Made Fibers GmbH
© KEB Automation KG