PAPER MACHINE WINDER VIBRATIONS: MECHANISMS AND FAULT DIAGNOSTICS

Charlie Hu
Mechanical Reliability Engineer, Opal Australian Paper, Maryvale Mill

Keywords: Paper machine winder, Nip load, Vibration mechanisms, Signal processing, Fault diagnosis.

During the paper winding process, both mechanical and control faults can trigger intensive reel vibrations, which not only cause a significant amount of production loss but may also damage the winder and create extra maintenance cost. These faults are not necessarily due to the failure of a specific component such as a bearing or a control card. Rather, they could be an indiscernible roll misalignment or the improper configuration of control parameters. Due to the intrinsic nonlinear nature of the winding process, these intensive vibrations can appear suddenly, without giving obvious warnings. The diagnosis of these winder faults is a challenge in the papermaking industry, partially because of the time-varying operational conditions, and partially because of the lack of integrated knowledge from winding mechanics and vibration analysis. This report presents an analytical approach for expeditiously understanding of winding vibrations, and a demonstrated troubleshooting procedure for practical applications.

This report includes four main sections. The first part will briefly introduce paper winding mechanics and the corresponding control logics. The effect of mechanical and control issues on the wound-in tension will be analyzed. The second part will focus on the interactions between rotating components and predict their manifestations in vibration signals. Main rotating components, including front and rear drums, the rider roll, and the paper reels, are considered in this part. The troubleshooting procedure is presented in the third part, which includes the recommended signal processing approach. Finally, two case studies are presented to support the identified vibration mechanisms in the winding process, and the effectiveness of the proposed fault diagnosis procedure. In case one, the vibration of a paper machine reeler is presented to show the importance of precise roll alignment, and the nonlinear feature of winding vibrations. Case two shows the process of identifying the root cause of intensive vibrations that often occur at the end of a winding cycle for a specific paper grade.

Charlie Hu is a mechanical reliability engineer in Australian Paper Maryvale. He has more than 10 years of research experience in machine condition monitoring and mechanical vibrations. After joining Opal, Charlie has helped to solve complex issues in paper machine with his analytical skills. His interests include vibration analysis, tuning of PID controller, Python coding, process data analysis and machine learning.