Segmented Composite Duct Molding Tool for Uniform Curing

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Solution Overview

Problem

Existing tooling for manufacturing aircraft turbomachine ducts in composite materials faces issues with large size, high mass, thermal inhomogeneity, poor mechanical properties due to inhomogeneous polymerization, difficulty in handling, inability to apply uniform pressure, and aerodynamic incompatibility, leading to defects and increased production costs.

Innovation Solution

A novel molding tool comprising a base and a body with removable parts, allowing fiber sheets to be draped over a rigid structure, enabling better thermal homogeneity, reduced mass, and simultaneous production of multiple ducts, with a remote heating system and vacuum application for improved pressure distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a steel mold with integrated heating system is used, then the mold can heat the preform during polymerization, but the mold becomes very large and heavy, making it difficult to handle

Engineering Contradiction:
Improveheating capabilityVSAvoidmold mass
Core Design Contradiction:
TemperatureVSWeight of stationary object

Solution Approach 1:

The heating system is extracted from the mold structure and relocated to an external position. The patent places heating elements outside the mold cavity, allowing the mold itself to be lightweight while still providing the necessary thermal energy for polymerization through external heating means.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The mold is divided into multiple separable parts rather than a single integrated structure. This segmentation allows the mold components to be smaller, lighter, and easier to handle individually, while collectively forming the complete molding system when assembled.

Inventive Principle:
Principle #1Segmentation

2Strength

If a steel mold with integrated heating system is used, then the mold can maintain structure during heating, but thermal inhomogeneity occurs in the resin during polymerization

Engineering Contradiction:
Improvemold structural stabilityVSAvoidthermal homogeneity
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

A flexible membrane is introduced as an intermediary layer between the preform and the rigid mold structure. This membrane allows for more uniform heat distribution across the preform surface while the rigid mold maintains its structural integrity, resolving the conflict between structural stability and thermal homogeneity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The mold system incorporates flexible or adjustable elements that can adapt during the heating process. The flexible membrane dynamically conforms to the preform shape and facilitates more uniform thermal contact, while the rigid mold provides stable structural support.

Inventive Principle:
Principle #15Dynamics

3Ease of manufacture

If a flexible membrane is used as tooling, then the preform can be molded, but insufficient pressure is applied leading to resin pockets without fiber reinforcement

Engineering Contradiction:
Improvemolding capabilityVSAvoidpressure distribution uniformity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The tooling system is segmented into multiple discrete elements rather than a single flexible membrane. This segmentation allows individual pressure points to be applied at strategic locations, ensuring uniform pressure distribution and preventing resin pockets while maintaining ease of manufacturing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The flexible membrane mechanical system is replaced or supplemented with a rigid mold structure that provides more reliable and uniform pressure application. The rigid structure maintains consistent contact pressure across the preform surface, eliminating the pressure distribution problems associated with flexible membranes.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Ease of manufacture

If a flexible membrane is used as tooling, then the preform can be molded, but the internal surface lacks aerodynamic compatibility due to surface undulations

Engineering Contradiction:
Improvemolding capabilityVSAvoidsurface quality
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The flexible membrane tooling is replaced with a rigid mold structure that provides a precise, stable surface for molding. The rigid mold maintains exact geometric fidelity throughout the molding process, producing surfaces with the required aerodynamic smoothness and eliminating undulations that occur with flexible membranes.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The rigid mold is divided into multiple precision-machined segments that can be assembled to form the complete tooling. This segmentation allows for precise manufacturing of each segment with tight tolerances, ensuring that the assembled mold provides a uniformly smooth surface for aerodynamic compatibility.

Inventive Principle:
Principle #1Segmentation

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 facilitates handling, ensures thermal homogeneity, improves mechanical properties, reduces manufacturing costs, and enhances aerodynamic compatibility, allowing for precise control of final geometry and simultaneous production of multiple ducts.

Implementation Method 1

with a vacuum maintained at the preform level

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 2

polymerizable resin, intended to impregnate and stiffen the preform, is injected into it

Methodology Applied
Scientific EffectImpregnation: Absorption (physical)

Implementation Method 3

the tooling continues to heat to complete the resin polymerization

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 4

complete the resin polymerization

Methodology Applied
Scientific EffectPolymerization: Photopolymerisation

Data Source

PatentEP4452589B1Tool and method for moulding a duct for an aircraft turbine engine
Publication Date: 2026.02.04 SAFRAN AIRCRAFT ENGINES SAS
  • EP4452589B1 patent drawingFigure 1~2
  • EP4452589B1 patent drawingFigure 3~4
  • EP4452589B1 patent drawingFigure 5~6

AI summary

The invention relates to a tool (30) for moulding a duct for an aircraft turbine engine, the duct being made of a fibre-based composite material and comprising a curved tubular portion, one end of which is connected to a peripheral flange, this tool (30) comprising: - a base (40); - a generally elongate and curved body (50), this body (50) being formed by an assembly of first parts (52) which are fitted tightly together and which include a first central release key (53) which extends from one end of the body (50) to the other and which is configured to be removed first upon release of the body (50). The invention also relates to a method for manufacturing a duct for an aircraft turbine engine using a tool (30) as previously described.