Multi-Layer Headbox for FBB Ply Bonding
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Solution Overview
Problem
The existing methods for producing Folding Box Board (FBB) face challenges in achieving strong bonding between the different plies due to varying properties of the filler, top, and back plies, leading to potential issues in processing and final product quality.
Innovation Solution
A method using a fiber web machine with a multi-layer headbox that ejects and merges pulp suspensions to create a filler ply with properties similar to the top and back plies, enhanced by the introduction of water layers with additives, such as starch, to improve bonding strength and bulk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If different pulp suspensions with varying properties are used to form filler ply, top ply, and back ply, then the manufacturing flexibility and adaptability are improved, but the bonding strength between individual plies deteriorates
Solution Approach 1:
The patent applies local quality by creating a multi-layer headbox system where different regions (layers) have different pulp suspension properties. The headbox divides the filler ply into multiple sub-layers (first, second, third layers) with varying stock compositions, allowing each layer to be optimized for bonding with adjacent plies while maintaining overall manufacturing flexibility.
Solution Approach 2:
The patent uses composite materials by combining multiple pulp suspensions with different properties within the filler ply. By creating a composite structure with layers of varying stock compositions (different fiber types, sizes, and proportions), the system achieves both adaptability in manufacturing and improved bonding strength through compatible interfaces between plies.
2Strength
If a multi-layer headbox is used to eject multiple stock layers, then the bonding strength between plies is improved through better stock compatibility, but the device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the headbox into multiple independent layers (first, second, third layers) that can be controlled separately. Each layer has its own diffuser and can receive different pulp suspensions, allowing complex bonding requirements to be met through modular layer construction rather than a monolithic complex system.
Solution Approach 2:
The multi-layer headbox serves multiple functions: it forms the filler ply, creates bonding interfaces with top and back plies, and allows independent control of each layer's stock composition. This multi-functionality reduces the need for separate devices for each function, managing complexity through integration.
3Strength
If water layers with additives are introduced between stock layers, then the bonding strength and bulk properties are enhanced, but the manufacturing process complexity increases
Solution Approach 1:
The patent uses water layers with additives as intermediary substances between the pulp stock layers. These water layers act as bonding agents that facilitate adhesion between adjacent plies while also contributing to bulk properties. The additives in the water layers enhance bonding without requiring complex chemical processing equipment.
Solution Approach 2:
The patent employs hydraulic principles by using water layers (fluids) to mediate between stock layers. The water-based bonding agents are introduced through the headbox system, utilizing fluid dynamics to distribute bonding materials evenly between layers during the forming process, avoiding the need for separate application equipment.
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
This approach significantly enhances the bonding strength between the individual layers, ensuring a stable multi-ply web with improved properties suitable for FBB production, while allowing for controlled adjustment of layer properties and additive distribution.
Implementation Method 1
guiding the different pulp suspensions through the diffusers of the multilayer headbox to eject them onto a wire
Implementation Method 2
dewatering the liquid substances to form a filler ply in the form of an at least three-ply web
Implementation Method 3
merging the at least three-ply web with a second web formed at a second head box, merging the at least three-ply web with a third web formed at a third head box
Data Source
Figure 1
Figure 2A~3
Figure 4
AI summary
A method of forming a multi-ply web in a fiber web machine, comprises the steps: - feeding different pulp suspensions to diffusers of a multi-layer headbox, - guiding the different pulp suspensions through the diffusers of the multi-layer headbox to eject them onto a wire of a forming section, the wire forming a closed loop, - dewatering the liquid substances to form a filler ply in the form of an at least three-ply web, - merging the at least three-ply web with a second web formed at a second head box ejecting pulp suspension on a wire of a second forming section, and merging the at least three-ply web with a third web formed at a third head box ejecting pulp suspension on a wire of a third forming section, wherein the third web is arranged on a side of the two-ply web opposite to that where the second web is arranged.