Composite Panel Contour Forming With Folded Dry Plies

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Solution Overview

Problem

Traditional methods for manufacturing composite panels require cutting to define the precise shape of the panel's outline, which is time-consuming and costly, and existing methods for manufacturing composite structures like tennis rackets do not efficiently address the need for clean contours and simplified production.

Innovation Solution

A method involving folding a portion of the first layer over a structural element, applying adhesive if necessary, and injecting thermoplastic or thermosetting resin into a mold to form a composite panel, using dry materials like carbon or Kevlar fibers, with optional post-curing to enhance mechanical strength and contour definition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional cutting methods are used to define the panel outline, then precise shape definition is achieved, but manufacturing time and cost increase

Engineering Contradiction:
Improvepanel outline precisionVSAvoidmanufacturing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The structural element is pre-formed with the desired panel outline shape before the composite manufacturing process. This preliminary shaping eliminates the need for post-manufacturing cutting operations, as the mold directly forms the final panel shape including the precise outline definition.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The structural element integration merges the outline definition function with the structural support function. By combining these functions into a single component that is molded directly into the panel, the process eliminates separate cutting operations while maintaining both structural integrity and precise shape definition.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of operation

If dry materials are used instead of pre-impregnated materials, then handling and layering become easier, but resin injection complexity increases

Engineering Contradiction:
Improvehandling easeVSAvoidresin injection system
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

A resin injection system uses hydraulic or pneumatic pressure to deliver resin through molds to the dry material layers. This automated injection method manages the complexity of resin delivery while maintaining the handling advantages of dry materials during assembly.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The material state changes from dry to resin-impregnated during the molding process. This parameter change occurs automatically through controlled resin injection, allowing easy handling during assembly while achieving proper material saturation for structural performance in the final product.

Inventive Principle:
Principle #35Parameter changes

3Strength

If adhesive is applied to the folded layer portion, then bonding strength improves, but process steps and time increase

Engineering Contradiction:
Improvelayer bonding strengthVSAvoidprocess time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The structural element acts as an intermediary between the folded layer portions, providing a bonding surface that eliminates or reduces the need for additional adhesive application. The structural element's geometry and material properties facilitate direct bonding while maintaining structural integrity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The folded layer portions self-bond through the structural element integration during the molding process. The compression and heating in the mold create sufficient bonding without requiring separate adhesive application steps, allowing the structure to self-assemble and bond in one operation.

Inventive Principle:
Principle #25Self-service

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

Facilitates easier handling and layering, reduces installation time and costs, and improves mechanical strength by using dry materials, allowing for complex shapes with minimal excess thickness and precise contour definition.

Implementation Method 1

inject a thermoplastic or thermosetting resin into the mold, in particular to impregnate the NP1, NP2 layers

Methodology Applied
Scientific EffectResin impregnation and curing: Absorption (physical)

Implementation Method 2

the thermosetting resin injected in step d) is selected from an epoxy, phenolic, or urethane type thermosetting resin; step e) is accompanied by heating; At the end of step e), a post-curing step f) is planned

Methodology Applied
Scientific EffectThermosetting resin curing: Chemical Bonding

Implementation Method 3

step e) is accompanied by heating

Methodology Applied
Scientific EffectThermal heating: Heating

Implementation Method 4

a post-curing step f) is planned, advantageously carried out in the mold used to obtain the panel

Methodology Applied
Scientific EffectThermal curing: Heat Treatment

Implementation Method 5

the structural element placed during step b) on the first layer has the desired shape of the peripheral contour of the composite panel

Methodology Applied
Scientific EffectGeometric constraint: Geometry

Data Source

PatentEP3648960B1Process for manufacturing a composite panel
Publication Date: 2026.02.11 HUTCHINSON AERONAUTIQUE & IND LTEE
  • EP3648960B1 patent drawingFigure 1(a)~1(d)
  • EP3648960B1 patent drawingFigure 1(e)~3(e)
  • EP3648960B1 patent drawingFigure 2(a)~2(c)

AI summary

The invention relates to a process for manufacturing a composite panel (PC, PC'), said process comprising the following steps: a) providing at least one first ply (NP1, NP1') of a woven or nonwoven dry material, said first ply defining a peripheral contour (CP, CP'); b) placing a structuring element (ES; EST, EF, ESR) inside the peripheral contour of said first ply, over at least one portion of this peripheral contour; then c1) either placing at least one second ply (NP2, NP'2) of a woven or nonwoven dry material, so that said second ply covers both the first ply and the structuring element; c2) or folding over at least one portion (PR) of the first ply (NP1, NP'1), this portion comprising the peripheral contour (CP), in order to cover the structuring element (ES) then placing a second ply (NP2, NP'2) of a woven or nonwoven dry material, so that said second ply (NP2, NP'2) covers the first ply (NP1, NP'1), but not the structuring element (ES); the stack thus formed at the end of step c1) or c2) being either already in a mold or outside of the mold and then placed in said mold, d) injecting a thermoplastic or thermosetting resin into the mold, in particular for impregnating the plies (NP1, NP'1; NP2, NP'2); e) pressing the assembly in the mold in order to obtain the composite panel.