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Roll grinding procedures, wheels, belts, setup, end relief, tips

Successful roll grinding depends on many factors. The knowledge and experience of an operator, the condition of the roll grinding equipment, and continued preventive maintenance of equipment, all contribute to the ability to meet dimensional tolerances and surface finish requirements.

Winding principles part 1 - TNT overview, effect of web tension

This article is the first in a short series which will explain how web tension, rider roll pressure, and drum torque ratio affect roll quality. Illustrations of key components and control principles will be presented. The series starts with an overview and discussion of web tension.

Steam & condensate 1 - overview, glossary and water evaporation

In this first in a two part series, We explain the terminology and working principles of a typical S&C system and how it controls steam pressure for optimum drying over the entire operating range.

Hydraulic controls improve performance, reliability - case study

In this case study, Valmet helped a northern USA mill upgrade its hydraulic controls to remove obsolescence, while also improving runnability and reliability.

Improving reel turnups for low downtime and high paper yield

The reel turnup process must be perfect in order to maintain high quality end product and avoid downtime. Successful turnups share key aspects, while others may benefit from a technology upgrade.

Preventive unwind stand maintenance reduces waste and downtime

The unwind is responsible for several functions in the finishing process, including supercalendering, coating, and rewinding paper into a denser, more stable roll. During operation, it endures constant tension, high speed and vibration, which slowly take their toll. So proper maintenance is essential.

Making the world a better place for children

Valmet’s global social responsibility program consists of several local programs around the world. In the Asia Pacific area, we have cooperated with The Mirror Foundation to improve the facilities at three rural schools in Thailand. The work was finalized earlier this year, and the project’s completion was celebrated in a special ceremony in March.

Calender safety - Handling calender rolls and parent rolls

Due to the weight and overall size of calender rolls, reel spools, and paper rolls, handling accidents can cause serious injury or death to personnel, and costly repairs to the roll, spool, or other equipment. However, handling accidents can be avoided if basic safety rules are followed.

Good headbox flow sheet handling and installation prevent damage

Flow sheets are a critical part of headbox performance. They are brittle and must be handled with care. Flow sheets are used to adjust the turbulence level and scale generated in the headbox.

Reading fluids circuit diagrams - pneumatic circuit examples

The previous articles in this series introduced fluids circuit elements and presented example hydraulic schematics. This article describes two example pneumatic schematic diagrams: winder lowering cradle safety pins and winder belted threader operation.