Selectively Permeable Veil for Resin Impregnation in Composite Preforms

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Solution Overview

Problem

Current methods for fabricating composite structures using resin infusion often result in incomplete resin impregnation, particularly in complex geometries, due to uneven resin flow and permeability issues within dry preforms.

Innovation Solution

A method involving the application of a selectively permeable veil with a predetermined spatial density pattern to reinforcement plies of the dry preform, which controls resin flow and impregnation by varying permeability, either by dissolving or melting into the resin, ensuring complete impregnation and enhanced toughness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If resin infusion is performed on complex geometry preforms using conventional methods, then resin flow can be achieved, but incomplete impregnation occurs in low permeability areas

Engineering Contradiction:
Improveresin impregnation completenessVSAvoidpermeability uniformity
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies a veil layer with spatially varying permeability properties to different regions of the preform. The veil has higher permeability in low permeability areas and lower permeability in high permeability areas, creating local quality variations that balance resin flow distribution and ensure complete impregnation throughout the complex geometry preform.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the permeability parameter of the veil layer to optimize resin flow. By selecting a veil with specific permeability characteristics that differ from the preform regions, the resin flow distribution is controlled to achieve uniform impregnation across areas with different inherent permeability properties.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If consumable flow media is placed on peel ply to promote resin flow, then resin distribution improves, but impregnation is still insufficient for complex preform geometries

Engineering Contradiction:
Improveresin distribution uniformityVSAvoidflow control mechanism complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent utilizes a porous veil layer as the flow control mechanism. The veil's porous structure provides inherent flow distribution capabilities without requiring complex mechanical or geometric features, achieving improved resin distribution through the material's intrinsic permeability properties.

Inventive Principle:
Principle #31Porous materials

3Strength

If resin infusion is performed on high integration complex preforms, then structural complexity is achieved, but resin starvation occurs in certain areas

Engineering Contradiction:
Improvepreform integration complexityVSAvoidresin impregnation completeness
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent introduces a veil layer as an intermediary between the resin source and the preform regions. This intermediate layer mediates resin flow by providing a controlled permeability path that directs resin to low permeability and low integration areas, preventing resin starvation while maintaining the desired structural complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach ensures uniform resin distribution and complete impregnation of complex preforms, preventing resin starvation and enhancing the structural integrity and toughness of the composite component.

Implementation Method 1

The selectively permeable veil is dissolved or melted into resin

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 2

The selectively permeable veil is dissolved or melted into resin

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

Resin is infused through the composite dry preform by application of vacuum pressure to a downstream end of the sealed chamber, drawing resin from an upstream resin supply through the composite dry preform

Methodology Applied
Scientific EffectVacuum pressure: Pressure Gradient

Data Source

PatentEP3290192B1Method of locally influencing resin permeability of a dry preform
Publication Date: 2021.12.29 THE BOEING CO
  • EP3290192B1 patent drawingFigure 1
  • EP3290192B1 patent drawingFigure 2~7
  • EP3290192B1 patent drawingFigure 2a~2c

AI summary

A method of locally influencing resin permeation through a dry preform (10) having one or more reinforcement ply layers (202a, 202b, 202c), comprising applying a selectively permeable veil 205 to at least one of the reinforcement ply layers (202a, 202b, 202c) of the dry preform (10); the selectively permeable veil having a veil pattern of a predetermined spatial density and being adapted to dissolve or melt into resin to at least locally impart toughness to the preform upon resin infusion and curing of the dry preform; infusing resin into the dry preform (10); and directing the resin through the selectively permeable veil (205) such that the resin impregnates through the dry preform (10).