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Dynamic roll balancing - why, how, measurement and specification

Although a roll is statically balanced, it may have an eccentric center of gravity which cannot be detected by simple static balance. This will become noticeable when the roll speed is increased, and an end-for-end motion occurs. Dynamic unbalance requires investigation to determine which end, or both, require counter-weighting.

On-machine grinding increases speed and quality, a case study

At a fine paper mill, despite every effort, sheet breaks had averaged more than six a day for the last several months. Two of the four dryers were shut down and the two functioning dryers would need to be taken off-line soon if nothing could be done...

Proper coater blade angle measurement, interpretation and setup

Measuring and interpreting coater blade wear angle can avoid problems such as scratching, poor coat weight appearance, wet bleeding and weeping at the blade tip. Correct positioning of the blade on its bevel will optimize sheet smoothness.

Spreader rolls - principle, problems, solutions and services

Spreaders deal with web instability, using the principles of tension and traction to overcome dishing and interweaving. Valmet spreader roll services ensure spreading efficiency with all-round cost control.

Improving extended nip press (ENP) performance and blanket life

Since 1980 the Extended Nip Press (ENP) has performed well. But there have been improvements since its initial entry in the market. These include prolonging the blanket/belt and felt life and improving sheet properties with oil lubrication showers, belt brushes, belt wipes, loading piston upgrades and geometry optimizations.

Supercalender process conditions, variables and grinding

Process variables affecting SC paper production, process conditions affecting supercalender polymer roll life and calender roll grinding recommendations.

Larger jumbo rolls increase pressroom breaks, a case study

Larger wound roll sizes dramatically increased press breaks for an LWC mill's customer. Process analysis and Valmet small fixes provided a temporary solution.

Improve roll asset management, reduce risk, lower costs (webinar)

A Valmet webinar reviewed the roll agreement concept including case studies of mill achievements. The recorded webinar is described here and available to view.

Safe and efficient calender roll removal - four methods

These methods of calender roll removal are recommended by Valmet. Other methods may be used, depending on style/size of calender & available lifting equipment.

Forming section troubleshooting checklist extends wire life

Wire life below expectations is of major concern to mill management. These tips are presented in a check list format for quick reference if the need arises.