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Hot water modules for calender rolls, recommended maintenance

Calender rolls are heated via heating modules to provide low-variance accurate roll temperatures. Follow these hot water module maintenance best practices.

Vibration analysis - introduction to techniques and equipment

This article provides a clear, effective and illustrated introduction to vibration analysis techniques, including principles, equipment and spectral analysis.

Web shifting - base paper, misalignment, free span and process

Web shifting can be caused by the paper or by something mechanically wrong in the web path. This article presents typical causes of sheet shifting. Most have to do with alignments, but base paper, drying and coating also have great impact.

Doctor and press fabric streaking cause scuff marking, case study

A paper machine with a tri-nip press experienced sheet quality problems with scuff marking after an outage. Two factors contributed - center roll doctor setup and felt cleaning. This case study details the analysis and resolution of the issues.

The 1 Mile Rule analogy of MD length profiles and bagginess

The greater the relative length differences are, the more severe the baggy lanes will be. Proper monitoring tools such as iRoll can help eliminate them.

Shoe press report - users group, onsite service, belts & rebuild

Maintaining your shoe press has a tremendous impact on paper quality and production line runnability. Valmet offers several services to maintain and improve shoe press capabilities, starting with the Shoe Press Users Group Conference scheduled for early 2018.

Coated board reel control rebuild reduces waste, case study

A coated board mill reduced bottom waste at the reel and increased board quality, with a rebuild from pneumatic to hydraulic reel control.

Control blade beam deflection to maintain coat weight profiles

Coater beams deflect due to coating temperatures, paper temperatures and the temperature of the environment. Newer and wider coating machines are equipped with beam heating/cooling chambers that can be controlled to maintain a straight beam and hence better coat weight profiles.

Calendering variables, properties, compression and plasticity

Behavior of paper properties during calendering and a description of the mechanisms of smoothness, gloss and web plasticity and response to compressive load.

Balancing rolls - balance and imbalance, isolating the problem

Unbalanced rolls hammer at the framework of the papermachine, leading to worn journals, bearings and covers. Balancing rolls lengthens component lifetimes.