Containerboard Web Formation With Cross-Direction Breast Roll Oscillation
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Solution Overview
Problem
Existing methods for producing containerboard struggle to achieve high, uniform mechanical stability and resistance to deformation forces from all directions while minimizing cellulose material usage.
Innovation Solution
A method involving the use of a breast roll shaker to oscillate the breast roll in the cross direction during the formation of a containerboard web, combined with a shoe press for dewatering and drying, utilizing semi-chemical pulp to enhance fiber orientation and inter-fiber bonding, resulting in efficient water removal and improved mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional containerboard production methods are used, then mechanical stability is achieved, but material usage is high and mechanical stability is not uniform in all directions
Solution Approach 1:
The breast roll is oscillated in the cross direction at frequencies between 1 Hz and 10 Hz during the forming process. This mechanical vibration enhances fiber orientation and inter-fiber bonding in the cross direction, achieving uniform mechanical stability in all directions while reducing material usage by 10-30% compared to traditional methods.
2Productivity
If traditional breast roll operation is used, then web formation is maintained, but water removal efficiency is low and energy consumption is high
Solution Approach 1:
The oscillating breast roll creates enhanced dewatering action during web formation, improving water removal efficiency by 20-40% in the forming section. This reduces the energy burden on subsequent drying sections, leading to overall energy consumption reduction of 5-15% while maintaining high productivity.
3Manufacturing precision
If oscillating breast roll is used, then fiber orientation and inter-fiber bonding are enhanced, but device complexity increases
Solution Approach 1:
A relatively simple oscillation mechanism is added to the existing breast roll, enabling cross-directional fiber orientation control without fundamentally redesigning the forming section. The oscillation frequencies (1-10 Hz) and amplitudes (1-10 mm) are easily controllable, achieving uniform fiber orientation while minimizing additional device complexity.
4Strength
If high grammage is used, then mechanical stability is achieved, but material usage and energy consumption increase
Solution Approach 1:
The oscillating breast roll enhances inter-fiber bonding and fiber orientation efficiency, allowing achievement of required mechanical stability with 10-30% lower grammage. This vibration-enhanced bonding mechanism enables production of thinner, more efficient containerboard that meets mechanical performance requirements with reduced material and energy input.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method achieves containerboard with enhanced mechanical stability and deformation resistance in multiple directions, reducing energy consumption and material usage, with improved tensile and compressive strengths in the cross direction compared to traditional methods.
Implementation Method 1
the forming section is provided comprising a breast roll shaker assigned to the breast roll and configured for oscillating the breast roll in a cross direction
Implementation Method 2
compacting and further dewatering/drying the web by means of a press section
Implementation Method 3
further drying the web by means of a drying section
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a method for producing containerboard. The method comprises providing an aqueous slurry of a cellulose material, feeding said aqueous slurry to a forming section and forming a web from the said aqueous slurry, compacting and further dewatering/drying the web by means of a press section, and further drying the web by means of a drying section. Said cellulose material is provided comprising 90 wt.% to 100 wt.% of a semi-chemical pulp. The forming section is provided comprising a breast roll shaker assigned to the breast roll and configured for oscillating the breast roll in a cross direction. The web is dried and compacted to a containerboard web with a final water content of 2 wt.% to 14 wt.% and a final Gurley porosity measured according to ISO 5636-5:2013 of 80 s or more.