Thermoplastic Acoustic Panel Lay-Up With Local Thermal Cycle Control

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Solution Overview

Problem

Current manufacturing processes for thermoplastic composite skins in aircraft engines, such as those used in engine casings or acoustic panels, face challenges in controlling the thermal cycle and crystallinity, leading to high energy consumption and fragmented production cycles due to the need for additional autoclave heating.

Innovation Solution

A draping tool with a thermal regulation device that applies localized heat and cooling to control the thermal cycle during the draping process, allowing precise control of crystallinity and adhesion without the need for energy-intensive autoclave cycles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If thermoplastic material is draped using conventional dispensing tools with pressure and heat, then adhesion between layers is achieved, but control over thermal cycle and crystallinity level is lost

Engineering Contradiction:
Improvecrystallinity controlVSAvoidthermal cycle control system
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The draping tool surface is preheated to a controlled temperature before the thermoplastic material is deposited. This preliminary thermal preparation allows the material to maintain controlled cooling rates during deposition, enabling crystallinity control without requiring complex post-deposition thermal cycles in autoclaves.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The draping tool surface acts as a thermal intermediary between the heating source and the thermoplastic material. By controlling the surface temperature of this intermediary, the patent enables indirect thermal management of the material's cooling rate and crystallinity development during the draping process.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If autoclave or oven consolidation is used to control thermal cycle and crystallinity, then desired material properties are achieved, but energy consumption increases and production cycle becomes fragmented

Engineering Contradiction:
Improvecrystallinity levelVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by stationary object

Solution Approach 1:

The patent combines the draping and thermal cycle control operations into a single integrated process. The draping tool simultaneously performs material deposition and thermal management, eliminating the need for separate autoclave or oven consolidation steps, thereby reducing energy consumption and streamlining the production cycle.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The thermal cycle control function is extracted from the conventional autoclave/oven process and integrated directly into the draping tool. This extraction allows thermal management to occur during the draping operation itself, removing the need for energy-intensive post-draping thermal processing.

Inventive Principle:
Principle #2Taking out (Extraction)

3Manufacturing precision

If autoclave or oven consolidation is used for thermal cycle management, then crystallinity control is achieved, but production cycle time increases

Engineering Contradiction:
Improvecrystallinity controlVSAvoidproduction cycle time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent maintains continuous useful action by performing thermal cycle management during the draping process itself. The controlled cooling of the material begins immediately upon deposition on the preheated tool surface, eliminating idle time between draping and thermal treatment, and enabling continuous production flow.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The draping tool surface is preheated in advance to the required temperature, so that when the material is deposited, the thermal cycle control begins immediately. This preliminary preparation eliminates waiting time and allows the crystallinity development to occur concurrently with the draping 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

Enables cost-effective and faster manufacturing by controlling crystallinity and adhesion, reducing energy consumption and streamlining production cycles.

Implementation Method 1

the draping tool includes a thermal regulation device configured to locally heat the surface of the draping tool

Methodology Applied
Scientific EffectLocalized heating: Heating

Implementation Method 2

the cooling rate of the newly deposited thermoplastic material, heated by the deposition tool, can therefore be controlled

Methodology Applied
Scientific EffectControlled cooling: Cooling

Implementation Method 3

a deposition tool configured to exert pressure on the thermoplastic material and to heat the latter during its draping

Methodology Applied
Scientific EffectPressure application: Compression

Implementation Method 4

the aforementioned dispensing tools provide the necessary pressure and heat for adhesion of the last layer deposited to the one being deposited

Methodology Applied
Scientific EffectThermal adhesion: Heating

Data Source

PatentEP4496692B1Improved method for the manufacture of a skin for an aeronautical engine
Publication Date: 2026.02.11 SAFRAN SA
  • EP4496692B1 patent drawingFigure 1~2
  • EP4496692B1 patent drawingFigure 3~4
  • EP4496692B1 patent drawingFigure 5

AI summary

Method for the manufacture of at least one skin (12), in particular of an acoustic panel (10) for an aeronautical engine, comprising the laying of a thermoplastic material (TP) on a surface (S) of a lay-up tool (200) via a depositing tool (100) configured to exert a pressure on the thermoplastic material (TP) and to heat the latter while it is being laid, wherein the lay-up tool (200) comprises a thermal regulation device configured to locally heat the surface (S) of the lay-up tool (200).