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A Big Leap in ERP Systems: An Integrative, Modular Approach for Paper and Board, Paper360º September/October 2024

Understanding the EUDR: Challenges and Opportunities for the Forest Products Sector, Paper360º September/October 2024

Faster Composition Analysis = Better QA, Paper360º January/February 2025

From Innovation to Impact: The Transformative Journey of the Pulp and Paper Industry, Paper360º January/February 2025

Pulp and Paper Machine Healthcare, Part 1: Digitalization Solutions for Condition Monitoring, Paper360º March/April 2025

Lubricants: Unsung Heroes of Sustainability, Paper360º May/June 2025

The Price Gap Between Hardwood and Softwood Pulp, Paper360º May/June 2025

Young Professional Perspective: Shaping the Future Through Mentoring, Paper360º March/April 2021

Young Professional Perspective: Shaping the Future Through Mentoring, Paper360º March/April 2021

TAPPI Journal Summaries, Paper360º May/June 2021

TAPPI Journal Summaries, Paper360º May/June 2021

Calender barring review with experiences, TAPPI Journal July 2022

ABSTRACT: Excessive calender vibration affects all styles of calender stacks from single to multi-nip, all hard rolls, or a combination of hard and soft rolls. Calender vibration can be forced vibration or self-excited vibration. Forced vibration occurs at the first few harmonics of the calender roll rotational speeds and is caused by imbalance, misalignment, eccentricity, etc. Self-excited vibration, the focus of this paper, occurs at higher frequencies. Feedback paths for self-excited vibration must be understood in order to ameliorate the problem. This is presented in the context of the historical development of the theory of self-excited feedback mechanisms, followed by a survey of self-excited feedback mechanisms in various types of calender stacks. Methodology to determine which feed-back path is present and techniques to control or eliminate the resulting vibration follow. To obtain a flavor of the types of problems faced and practical remedial actions, a variety of experiences with barring issues are provided.