Sandwich Panel Manufacturing Using Cushion Layer Pressing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for manufacturing sandwich panels, particularly those using prepregs and honeycomb cores, face challenges in achieving smooth surface flatness and productivity due to issues like rough protrusions, recesses, and manual filling processes.

Innovation Solution

The use of a metal plate with a flat surface as a pressing tool, combined with a cushion layer, to heat and pressurize the core layer and prepregs, ensuring uniform stress application and improved surface flatness, and the integration of thermoplastic resin sheets for enhanced productivity and surface smoothness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an autoclave is used to manufacture sandwich panels, then the sandwich panel can be cured and adhered, but rough protrusions, recesses, holes, or partial surface loss are formed on the surface

Engineering Contradiction:
Improveadhesion between laminate and honeycomb coreVSAvoidsurface flatness
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

A cushion layer is introduced as an intermediary between the pressing plate and the prepreg/honeycomb core assembly. This cushion layer distributes the pressing force uniformly, preventing direct contact that causes surface defects while still enabling effective adhesion during curing.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The pressing method is changed from direct high-pressure autoclave curing to controlled pressing through a cushion layer. This parameter change in the pressing mechanism allows for more uniform stress distribution, eliminating surface protrusions and recesses while maintaining adhesion quality.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If manual filling is performed to repair surface defects, then surface quality can be improved, but productivity is degraded

Engineering Contradiction:
Improvesurface flatnessVSAvoidmanufacturing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The cushion layer is used during the initial curing process to prevent surface defects from forming in the first place. This preliminary preventive action eliminates the need for subsequent manual filling operations, thereby maintaining high productivity while ensuring surface quality.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If paper phenol plate is pressed to the laminate without autoclave, then some surface improvement is achieved, but surface roughness is not sufficiently smooth

Engineering Contradiction:
Improvesurface flatnessVSAvoidsurface smoothness quality
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The material of the pressing plate is changed from paper phenol plate to a cushion layer system. This parameter change in the pressing interface material provides superior surface smoothness that paper phenol plates cannot achieve, while still being applicable without requiring an autoclave.

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

This approach results in sandwich panels with significantly improved surface flatness and productivity, eliminating the need for manual filling and reducing defects, while allowing for automated processing and enhanced mechanical properties.

Implementation Method 1

a core layer and a prepreg are heated and pressurized while pressing the core layer and the prepreg with a pressing plate

Methodology Applied
Scientific EffectMechanical pressure: Compression

Implementation Method 2

a core layer and a prepreg are heated and pressurized while pressing the core layer and the prepreg with a pressing plate

Methodology Applied
Scientific EffectThermal heating: Heating

Data Source

PatentEP3489007B1Method for manufacturing sandwich panel, sandwich panel, composite material sheet, and curved panel member
Publication Date: 2021.08.04 SUMITOMO BAKELITE CO LTD
  • EP3489007B1 patent drawingFigure 1A~1C
  • EP3489007B1 patent drawingFigure 2
  • EP3489007B1 patent drawingFigure 3A~3C

AI summary

A method for manufacturing a sandwich panel of the present invention includes a preparation step of preparing a sheet-like core layer having a honeycomb structure and sheet-like prepregs, a disposition step of disposing the prepregs on opening surfaces of the core layer on an upper surface side and a lower surface side respectively, and a step of obtaining a sandwich panel by heating and pressurizing the core layer and the prepregs while pressing flat surfaces of metal plates as pressing plates to the prepregs and then by separating the metal plates from resin plates made of cured substances of the prepregs.