Zigzag Wood Core Layer for Stable Fastener Attachment

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Solution Overview

Problem

Existing multi-layer composites with loosened core layers have low homogeneity due to large cavities, leading to instability when fastened with nails or screws, and require large high-quality veneer for production, which limits their mechanical stability and practical application.

Innovation Solution

A pressure-formed core layer with zigzag-shaped wooden elements, where adjacent edges form a common edge and intersect at a non-zero angle, are firmly connected, often using adhesives, to create a more homogeneous and stable structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If a loose core layer structure is used to achieve lightweight properties and damping effect, then weight reduction and energy absorption are improved, but homogeneity deteriorates due to large voids causing fastener instability

Engineering Contradiction:
Improveweight of multilayer compositeVSAvoidfastener stability
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent changes the geometric parameters of the core layer by introducing zigzag-shaped wooden elements with specific dimensions (element thickness 0.5-5mm, zigzag amplitude 2-20mm, zigzag wavelength 10-100mm). This parameter optimization allows the core layer to maintain low density while achieving sufficient homogeneity for fastener stability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite core layer combining wooden zigzag elements with adhesive material filling the voids. This composite structure maintains the lightweight advantage of the loose structure while the adhesive-infused voids provide the homogeneity needed for reliable fastener attachment

Inventive Principle:
Principle #40Composite materials

2Strength

If large high-quality veneer pieces are used to produce large-format core layers, then structural integrity is improved, but material cost and availability requirements worsen

Engineering Contradiction:
Improvestructural integrity of core layerVSAvoidveneer material requirement
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The patent divides the core layer into multiple smaller zigzag-shaped wooden elements instead of using large continuous veneer pieces. These segmented elements (each can be produced from small veneer scraps) are assembled together with adhesive to form the complete core layer, eliminating the need for large high-quality veneer while maintaining structural integrity through the interconnected zigzag geometry

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses zigzag (curved/wavy) geometry for the wooden elements instead of flat straight pieces. This curved configuration increases the effective structural length and interlocking capability within the same material volume, providing enhanced structural integrity without requiring larger veneer pieces

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Productivity

If a loose core layer with large voids is used, then lightweight properties are improved, but manufacturing homogeneity deteriorates leading to reduced fastener stability

Engineering Contradiction:
Improvelightweight property efficiencyVSAvoidhomogeneity of core layer
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent optimizes the geometric parameters of the zigzag elements (amplitude, wavelength, thickness) and their spatial arrangement to achieve a balance between void volume (for lightweight properties) and distribution uniformity (for homogeneity). The specific parameter ranges ensure sufficient material distribution for fastener stability while maintaining low density

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses adhesive material as an intermediary substance that fills and binds the zigzag wooden elements together. This adhesive mediator distributes stress and connects the discrete elements, creating a homogeneous effective structure that supports fasteners while preserving the lightweight zigzag geometry

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution enhances the mechanical stability of the core layer and multi-layer composite, allowing for reliable fastening and improved attachment to carriers, while reducing the need for large veneer pieces, resulting in a more efficient and stable lightweight building material.

Implementation Method 1

wherein the two elements are firmly connected to each other at the point of intersection

Methodology Applied
Scientific EffectAdhesive bonding: Adhesive

Implementation Method 2

pressure-formed core layer with zigzag-shaped wooden elements

Methodology Applied
Scientific EffectCompression molding: Compression

Data Source

PatentEP3269893B1Method for pressure-reforming a core layerand a multi-layer-composite comprising zig-zag shaped wood elements
Publication Date: 2021.03.10 WOOD INNOVATIONS
  • EP3269893B1 patent drawingFigure 1a~1c
  • EP3269893B1 patent drawingFigure 2a~2b
  • EP3269893B1 patent drawingFigure 2c~2d

AI summary

Method for producing a compression-molded core layer, comprising step (iv): (iv) compression-molding a core layer, wherein the core layer has zigzag-shaped elements made of wood, which have plate-shaped areas arranged in a zigzag pattern, wherein a zigzag area of ​​one element shares a common edge with an adjacent zigzag area of ​​the zigzag-shaped element, and wherein zigzag-shaped elements are arranged in the core layer such that two such edges of two zigzag-shaped elements, which may be the same or different from each other, intersect at an angle other than zero, wherein the two elements are firmly joined together at the point of intersection by means of an adhesive.