Composite Part Liquid Compaction for Uniform Fiber Volume

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Solution Overview

Problem

Existing methods for manufacturing large but thin composite parts, such as aircraft parts such as aircraft parts, fail to achieve satisfactory control over fiber volume percentage and thickness uniformity, particularly in the aircraft's aft sections, due to non-uniform compaction pressure and fiber volume percentage variations, especially when parts are inclined or extend vertically, and require precise pressure control.

Innovation Solution

A method using a flexible membrane to separate impregnation and compaction chambers, with a compression fluid having a density close to the impregnation fluid, maintaining a nearly constant compaction rate and pressure difference, ensuring uniform fiber volume percentage and thickness across the part.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a flexible membrane is used to eliminate tooling tolerance issues, then ease of manufacture is improved, but manufacturing precision deteriorates due to non-uniform compaction pressure along the height of the membrane

Engineering Contradiction:
Improveease of manufactureVSAvoidmanufacturing precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent changes the density parameter of the compression fluid to match the density of the impregnation fluid. This parameter change ensures that hydrostatic pressure variations due to altitude differences are identical on both sides of the membrane, resulting in uniform compaction pressure along the entire height of the membrane and resolving the manufacturing precision issue.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If compaction pressure is applied to force slurry through fibrous preform, then productivity is improved, but manufacturing precision deteriorates due to unwanted variations in fiber volume percentage

Engineering Contradiction:
ImproveproductivityVSAvoidfiber volume percentage control
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent adjusts the density parameter of the compression fluid to be equal to the density of the impregnation fluid. This ensures that pressure differences caused by altitude variations are identical on both sides of the membrane, maintaining uniform compaction pressure and consistent fiber volume percentage throughout the part while preserving productivity.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If very low pressure is applied on the preform, then manufacturing precision is improved for pressure control, but productivity deteriorates due to difficulty in maintaining constant pressure difference

Engineering Contradiction:
Improvepressure control precisionVSAvoidproductivity
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent changes the density parameter of the compression fluid to match the impregnation fluid density. This parameter change enables very low pressure differences to be maintained automatically throughout the part, as hydrostatic pressure variations due to altitude are identical on both sides of the membrane, thus achieving both precision and productivity.

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

Achieves uniform compaction pressure and fiber volume percentage, allowing for precise control of pressure differences and improved manufacturing of large, thin parts with complex geometries.

Implementation Method 1

pressure is first applied to the membrane by injecting a compression fluid into the compaction chamber

Methodology Applied
Scientific EffectHydrostatic pressure: Pascal's Law

Implementation Method 2

The fibrous preform is then impregnated with a slurry containing particles of a matrix precursor or with a resin, depending on the desired matrix type. Impregnation is achieved by injecting the slurry or resin into the mold cavity containing the fibrous preform, allowing it to gradually penetrate the material.

Methodology Applied
Scientific EffectImpregnation: Absorption (physical)

Implementation Method 3

solidification treatment of the matrix precursor within the fibrous preform so as to obtain a part of composite material comprising a fibrous reinforcement bonded by a solid matrix

Methodology Applied
Scientific EffectSolidification: Freezing

Data Source

PatentEP4466137B1Method for manufacturing a part made of composite material with liquid compacting
Publication Date: 2025.12.31 SAFRAN CERAMICS SA
  • EP4466137B1 patent drawingFigure 1
  • EP4466137B1 patent drawingFigure 2
  • EP4466137B1 patent drawingFigure 3

AI summary

The invention relates to a method for manufacturing a part made of composite material, comprising the arrangement of a fibrous preform (10, 20) in the impregnation chamber (110, 210) of a mould (100, 200), the impregnation chamber (110, 210) being closed by a flexible membrane (130, 230) separating the impregnation chamber (110, 210) from a compaction chamber (120, 220), an impregnation fluid (1000, 3000) being injected into the impregnation chamber (110, 210) and a compression fluid (2000, 4000) being injected into the compaction chamber (120, 220), the compression fluid (2000, 4000) being a liquid in which the value of the density is between 60% and 125% of the density of the impregnation fluid (1000, 3000).