Flat Composite Preform Production with Thermoformable Core

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing methods for producing composite parts with complex shapes are difficult to automate, leading to limited production rates and are mainly suited for high-end applications, as they require manual handling and assembly of multiple preforms, making it challenging to achieve efficient and cost-effective production of parts with non-parallel planes.

Innovation Solution

A method involving flat draping of deformable dry folds, positioning a thermoformable core, sewing between laminations, thermoforming the preform to the part shape, and impregnating with a polymer, allowing for the production of a three-dimensional part using a single preform with automated processes and improved handling and deformation capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If manual assembly of multiple preforms is used to produce complex-shaped composite parts, then manufacturing flexibility and adaptability are maintained, but productivity is low and automation is difficult to achieve

Engineering Contradiction:
Improvemanufacturing flexibilityVSAvoidproduction rate
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The invention divides the complex three-dimensional part into multiple two-dimensional plies that are draped flat on a mandrel. Each ply can be independently manufactured and positioned, then assembled into the final complex shape. This segmentation allows automated flat draping operations while maintaining the capability to produce complex geometries through the layered assembly process.

Inventive Principle:
Principle #1Segmentation

2Shape

If multiple preforms are assembled manually in the tool before impregnation, then complex shapes with non-parallel planes can be achieved, but the process is difficult to automate and handling is complex

Engineering Contradiction:
Improvecomplex shape capabilityVSAvoidautomation difficulty
Core Design Contradiction:
ShapeVSExtent of automation

Solution Approach 1:

The invention transitions from assembling three-dimensional preforms to draping two-dimensional plies on a mandrel. By working in the flat two-dimensional domain during manufacturing and then forming the three-dimensional shape through draping and impregnation, the process becomes amenable to automation while still achieving complex geometries. The mandrel serves as the intermediary that enables this dimensional transformation.

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

3Shape

If a core is introduced during draping to separate folds of lamination, then the complex shape is achieved, but the operation becomes very delicate and difficult to perform

Engineering Contradiction:
Improvefold separation capabilityVSAvoidoperation difficulty
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The core is positioned on the mandrel before the plies are draped over it. This preliminary positioning allows the plies to be draped smoothly around the core without the need for delicate manual manipulation during the draping process itself. The core acts as a pre-positioned structural element that guides the ply formation, simplifying the overall manufacturing operation.

Inventive Principle:
Principle #10Preliminary action

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 method enables the production of complex-shaped composite parts with a single preform and impregnation operation, facilitating automation, improved handling, and deformation capabilities, while maintaining mechanical integrity and flexibility in polymer selection, suitable for industrial-scale production.

Implementation Method 1

positioning on said first lamination a core made of a thermoformable material extending over part of the surface of the first lamination; an operation of draping a second lamination of deformable dry plies extending above the core and up to the first lamination; wherein between step d) and step e) a step consists in: j. thermoforming the preform comprising the core to the shape of the part

Methodology Applied
Scientific EffectThermoforming: Heat Treatment

Implementation Method 2

the impregnation of the preform by said polymer is carried out under pressure or under low pressure, the impregnation front progressing parallel or perpendicular to the stack of plies constituting the preform

Methodology Applied
Scientific EffectPressure-driven impregnation: Pressure Increase

Implementation Method 3

impregnating the dry preform with a polymer; consolidating said polymer

Methodology Applied
Scientific EffectCuring: Phase Change

Data Source

PatentEP3365162B1Method for flat production of a complex composite preform
Publication Date: 2023.09.06 INST DE RECH TECHQUE JULES VERNE
  • EP3365162B1 patent drawingFigure 1~2
  • EP3365162B1 patent drawingFigure 3~4
  • EP3365162B1 patent drawingFigure 5~6

AI summary

The invention relates to a method for producing a composite part (100) having continuous fibre reinforcement from a dry preform, said method comprising: a. flat lay-up of a first layering (311, 312) of deformable dry plies, b. positioning, on said first layering, a thermoformable core (200) that extends onto a portion of the surface of the first layering, c. lay-up of a second layering (321, 322) of deformable dry plies, extending above the core and up to the first layering, d. stitching (410, 420, 430) along a defined contour, said stitching connecting and extending between the second and the first layerings, e. placing the preform obtained at the end of step d) into the three-dimensional cavity of a mold (600), f. impregnating the dry preform with a polymer, comprising between step d) and step g) a step consisting of: j. thermoforming the preform comprising the core (200) into the shape of the part.