Wet end tools for paper/board quality and strength (webinar)
May 25, 2021
Why is a paper machine good at making one grade of paper and not good at making another one? How can a wet end modification produce a better and stronger sheet? A webinar on June 2nd, 2021 described how each component located at the wet end of a paper machine, can be operated to optimize the quality and the strength of a specific grade.
Click HERE to view the webinar.
During the webinar, Pierre Gélinas, senior product manager for headbox and forming sections, explained:
- Strength and headbox fundamentals
- How refining can impact positively or negatively paper strength
- How headbox design has an impact on sheet properties
- How a breast roll shaker can improve productivity
- How the dewatering capacity of a former can play a role in this system
Here is an example of what you will learn about wet end tools during the webinar...
Refining as a wet end tool
The evaluation of fiber morphology through microscopic analysis gives mill technologists insight into how fibers develop in refining. The fiber treatment depends on the filling used and the refining conditions. Refining affects the fiber properties and paper properties are a product of the fiber properties.
Refining effect on tensile and tear strength - traditional vs. OptiFiner Pro
The graphic shows a mill comparison between traditional refining and Valmet's OptiFiner Pro refining. Clearly, the OptiFiner Pro refining provides better strength, both in tensile and tear, than conventional refiners
Refining - pros
- With good fibrils development comes better strength - if you are not drainage limited.
Refining - cons
- Lost of freeness (CSF) in the pulp
- Harder to dewater in the forming section
- Will reduce slice opening
- Will increase headbox consistency and affect formation
- Will increase TSI MD/CD Ratio
- Will lose strength from the wet end
- Will slow down the machine as it will be more difficult to dry
Refining - ideal situation
- Refiners should operate to control sheet porosity.
- Minimum refining is better.
If you have any questions about wet end tools, refining, headboxes, forming or dewatering, watch this informative webinar and contact your Valmet representative.
