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Web handling, construction & proper setup of bowed roll spreaders

Bowed spreader rolls are the most commonly used spreader roll and are critical to most web handling processes. Learn how the construction, web orientation, cover material and wrap angles play important parts in web handling.

Proper press maintenance, key operational checks and upgrades

Loading systems are an essential part of the press section. Regular inspection and maintenance are needed on a regular basis to maintain machine high runnability.

Instructions for safe removal of calender stack rolls and drives

Machine calender rolls are typically removed using a house crane and slings. This article presents typical stack roll removal instructions and safety. Always refer to original equipment supplier documentation and mill procedures for the actual procedures.

Winding principles part 3 - drum torque control methods, summary

When web tension and drum nip pressure are constant, drum torque will assure uniform or diminishing roll hardness from the core toward the outside of the rolls.

Winding principles part 2 - effect and elements of nip pressure

The relationship between rider roll pressure and shipping roll hardness is neither simple nor direct. This second article in the Winding Principles series explores the interrelationship between rider roll pressure, relief pressure, roll weight and nip load.

Excellent results with suction box showering, rebuild case study

A newsprint mill in southern USA was losing suction in one of their suction couch rolls. A Valmet rebuild resulted in two years of run time with very little internal pulp buildup or seal strip wear.

Overview and troubleshooting of size press threading system

This article presents an example multiple-device threading system, briefly describing each device, and then lists methods to troubleshoot the threading system.

Vibration monitoring and analysis in tri-nip press, case study

A paper machine experienced vibration in its tri-nip press on the tending side only. Valmet condition monitoring and vibration analysis used synchronous time averaging (STA) to assist in solving the problem.

Spreader roll reconditioning and upgrades optimize performance

Valmet spreader roll reconditioning service leads to a clear increase in service intervals and cuts overall maintenance costs. In addition to keeping spreader rolls in excellent condition, the spreader roll service ensures optimized roll performance, improved end product quality and reliable, wrinkle-free runs.

Floor protection in recovery boilers with decanting floors

Optimizing both the floor protection methods and materials and the cooling, washing and cleaning practices can yield significant savings in mill outage time and corresponding increases in mill production and reduced risk of mechanical damage due to mechanical cleaning or hydro blasting during floor cleaning.