Half-Cut Core Material Sheet for 3D Composite Formability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for manufacturing composite materials face challenges in achieving good formability into three-dimensional shapes and productivity due to issues with transferring plate-shaped flakes and requiring multiple cutting and embossing steps, leading to labor-intensive processes and potential detachment of material pieces.

Innovation Solution

A sheet for core material layer is processed using half-cutting methods like press-cutting or laser-cutting, with divided portions arranged two-dimensionally and connected by extending portions through the thickness, allowing for improved formability and productivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If plate-shaped flakes are transferred from a transfer sheet to skin material, then the composite material can be formed into three-dimensional shapes, but the transferring process becomes labor-intensive and productivity decreases

Engineering Contradiction:
Improveformability into three-dimensional shapeVSAvoidproductivity
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The core material sheet is divided into multiple divided portions that are separated by cuts formed by half-cutting. These divided portions can independently follow curved surfaces while remaining connected through extending portions, enabling three-dimensional formability without requiring transfer to skin material

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces cuts that extend through the thickness direction of the core material sheet, creating a three-dimensional structure with divided portions and extending portions. This dimensional approach allows the material to conform to curved surfaces while maintaining structural integrity and eliminating the need for transfer processes

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of manufacture

If multiple cutting and embossing steps are conducted to form material attenuating portion and bridge portion, then the reinforcement structure can be created, but the number of steps increases and productivity is reduced

Engineering Contradiction:
Improvestructure formation capabilityVSAvoidproductivity
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The invention combines the functions of cutting and forming into a single half-cutting process. The cuts simultaneously create divided portions and extending portions that connect them, eliminating the need for separate embossing steps to create bridge portions

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The half-cutting process is performed in advance on the core material sheet before lamination, pre-forming the divided portions and extending portions. This preliminary action eliminates the need for subsequent embossing or additional forming steps after lamination

Inventive Principle:
Principle #10Preliminary action

3Strength

If a sheet material with high stiffness is used for core material layer, then the composite material achieves high stiffness, but the sheet cannot follow curved surfaces with large curvature

Engineering Contradiction:
ImprovestiffnessVSAvoidformability into curved shape
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The high-stiffness core material sheet is segmented into divided portions separated by cuts. This segmentation allows each portion to independently deform and follow curved surfaces while the overall structure maintains high stiffness through the connecting extending portions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies different structural characteristics to different parts of the core material sheet. The divided portions can locally deform to follow curved surfaces, while the extending portions maintain structural integrity. This local differentiation enables both formability and stiffness preservation

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4659926A1Core material sheet, composite material, method for manufacturing core material sheet, and method for manufacturing composite material
Publication Date: 2025.12.10 MILLEFEUILLE COMPOSITE CORP
  • EP4659926A1 patent drawingFigure 1~2
  • EP4659926A1 patent drawingFigure 3(a)~3(d)
  • EP4659926A1 patent drawingFigure 4~5

AI summary

To provide a composite material with good formability into a three-dimensional shape and good productivity, a sheet for core material 10 to be used for manufacturing a composite material 30, comprising a sheet for core material layer 11 to be used for a core material layer 33 of the composite material 30 in which multiple divided portions divided from each other with cuts formed by half-cutting one face side of the sheet for core material layer in a direction of its thickness are arranged two-dimensionally in a plan view, the sheet for core material layer having the traces that half-cutting was conducted by press-cutting or laser-cutting.