End-Grain Wood Panel Grain Orientation

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Solution Overview

Problem

Existing wood-based laminates and panels lack sufficient shear stress and flexural strength, and exhibit inhomogeneity due to varying wood densities and grain orientations, which limits their performance in structural applications.

Innovation Solution

The development of end-grain wood panels composed of veneers with grain orientations deviating by 45° to 90° from adjacent layers, creating anisotropy and enhancing shear and flexural strength, using balsa wood veneers with specific density ranges and a method of layering and adhesive application to achieve homogeneous properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If wood-based laminates and panels are made with conventional grain orientations, then manufacturing is simpler, but shear stress and flexural strength are insufficient

Engineering Contradiction:
Improveshear stress and flexural strengthVSAvoidlayering complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The panel is segmented into multiple veneer layers with distinct grain orientations. Each layer is oriented at a specific angle (45° to 90° deviation) relative to adjacent layers, creating a segmented anisotropic structure that systematically distributes and resists applied stresses, thereby enhancing overall shear and flexural strength.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention creates a composite wood structure by combining veneers with different grain orientations in a controlled sequence. This composite arrangement leverages the anisotropic properties of wood fibers at different angles to achieve superior mechanical performance that exceeds that of conventional isotropic wood panels.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If wood panels are made with uniform grain orientation, then manufacturing is easier, but homogeneity is reduced due to varying wood densities

Engineering Contradiction:
ImprovehomogeneityVSAvoidproduction complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

Different regions of the panel (individual veneer layers) are assigned different grain orientations based on their positional requirements. This local differentiation in grain direction creates a systematically varied structure that compensates for natural density variations in wood, achieving enhanced homogeneity in mechanical properties across the entire panel.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The grain orientation parameter is systematically changed between adjacent veneer layers (45° to 90° deviation). This parameter variation transforms the panel's mechanical behavior, creating an anisotropic composite structure that achieves superior homogeneity and strength while providing clear manufacturing guidelines for consistent production.

Inventive Principle:
Principle #35Parameter changes

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 end-grain wood panels demonstrate significantly improved shear stress and flexural strength, along with increased homogeneity, making them suitable for high-load applications such as structural components and composite materials.

Implementation Method 1

The individual veneer sheets are stacked on top of each other so that their broad sides are facing each other... the individual wood veneers deviating from the grain direction of the adjacent wood veneer(s) by 45° to 90°

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP2569154B1Multilayer veneer - form
Publication Date: 2020.01.01 A COMPOSITES INT AG
  • EP2569154B1 patent drawingFigure 1
  • EP2569154B1 patent drawingFigure 2~3
  • EP2569154B1 patent drawingFigure 4

AI summary

The invention relates to a multi-layer moulding (1) having a high structural load-carrying capacity, comprising two opposite broad faces (10, 11) and an end face (6a, 6b, 6c, 6d) that extends around the sides, containing, in layers, broad face on broad face, laminated veneers (2, 2', 2", 2"', 3) and adhesives between the veneers (2, 2', 2", 2"', 3). The veneers (2, 2', 2", 2"', 3) are laminated in such a manner that the grain (4) of at least one of the veneers (2, 2', 2", 2"', 3) deviates by 45° to 90° from the grain (4) of the other veneer or veneers (2, 2', 2", 2"', 3), and in such a manner that the grain (4) of the veneers deviates by 22.5 to 67.5° with respect to a surface normal to an end face (6a, 6b, 6c, 6d) of the moulding (1).