Multilayer Laminated Board Production with Density Balance
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Solution Overview
Problem
Current wood panel production methods face challenges in achieving dimensional stability and preventing warping due to internal stresses, particularly in multilayer boards with asymmetrical structures, where differences in moisture content and density between layers lead to instability and warping.
Innovation Solution
A method for producing multilayer laminated boards with individually controlled layers, where the moisture content and density differences between adjacent layers are managed within specific tolerances to ensure structural stability, using a combination of fiber and particle layers with controlled weight and granulometry, and applying binders like phenoplast and aminoplast resins to maintain flatness and prevent warping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multilayer boards with asymmetrical structures are produced using conventional methods, then structural complexity and design flexibility are improved, but dimensional stability deteriorates due to internal stresses causing warping
Solution Approach 1:
The patent applies asymmetry principle by intentionally designing multilayer boards with asymmetrical structures where different layers have different materials, thicknesses, or densities. This allows design flexibility while maintaining stability through controlled asymmetry - the asymmetrical structure is carefully engineered so that the sum of densities from external layers to the geometric center on both sides remains equal, preventing warping while achieving structural versatility.
Solution Approach 2:
The patent employs parameter changes by precisely controlling key parameters such as moisture content, density, and thickness of each layer. The method requires that the sum of densities of layers on either side of the geometric center has a maximum admissible variability of 10% (preferably 5% or 3%), and the absolute difference in moisture content between adjacent layers is controlled within 1-10 percentage points. These parameter controls enable asymmetrical designs while maintaining dimensional stability.
2Adaptability or versatility
If layers with different moisture content and density are used to create asymmetrical structures, then design freedom is improved, but manufacturing precision deteriorates due to difficulty in controlling warping
Solution Approach 1:
The patent implements feedback control by establishing precise tolerance limits for manufacturing parameters and using these as control criteria during production. The method specifies that the sum of densities from external layers to the geometric center on both sides must be equal within 10% variability (preferably 5% or 3%), and moisture content differences between adjacent layers must be controlled within 1-10 percentage points. These feedback-controlled parameters enable manufacturers to achieve both design freedom and warping control precision.
3Stability of the object's composition
If symmetrical structures are used to prevent warping, then dimensional stability is improved, but design flexibility deteriorates due to structural constraints
Solution Approach 1:
The patent resolves this contradiction by redefining symmetry requirements - rather than requiring complete symmetry in layer configuration, the patent requires symmetry only in the sum of densities from external layers to the geometric center on both sides. This allows asymmetrical layer arrangements (different materials, thicknesses, or configurations) while maintaining the density balance needed to prevent warping, thereby achieving both dimensional stability and design flexibility.
4Reliability
If individual layer control is implemented to ensure stability, then manufacturing complexity is improved, but production efficiency deteriorates due to additional control steps
Solution Approach 1:
The patent manages the trade-off between reliability and productivity by focusing individual layer control on critical parameters only - specifically the sum of densities from external layers to the geometric center (with maximum 10% variability, preferably 5% or 3%) and moisture content differences between adjacent layers (controlled within 1-10 percentage points). By concentrating control efforts on these key parameters rather than all possible variables, the patent ensures board stability while minimizing the impact on production efficiency.
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 ensures the production of stable, flat boards with symmetrical or asymmetrical structures by compensating forces between layers, preventing warping and maintaining uniform density profiles, thereby enhancing the aesthetic and functional quality of the boards.
Implementation Method 1
deposit a plurality of fibers or particles mixed with binder substances and/or other chemical additives
Implementation Method 2
compact the multiple layers deposited in the steps a) to e) in order to form the board in the final thickness thereof by using pressure and heat
Implementation Method 3
pre-compact using pressure; pre-compact and optionally pre-heat the assembly of layers deposited in the previous steps
Implementation Method 4
thermal energy input through the heating plates is symmetrical as a result of common thermal oil input through the same pump to the upper and lower plate
Data Source
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AI summary
The method is carried out by means of the stacked deposition of a series of layers of fibers and/or particles with a binder material and/or other chemical additives on a conveyor belt until a multilayer mat is produced, in which the layers are physically different from one another. The method comprises: - defining the final thickness and density of the board; - defining the number of layers forming the board and the type of material to be used for each layer; - selecting and preparing the constituent material of each layer to be formed; - depositing, in a stacked and staggered manner, the layers previously defined according to weight per m2 of each layer; - pre-compacting and, optionally, pre-heating the mat; - compacting the mat using pressure and heat. The invention also relates to the board produced using said method for the production of a symmetrical or asymmetrical, stable board.