Composite Material Cleaning for Adhesive Bonding

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Solution Overview

Problem

Internal contamination within composite parts, such as those used in helicopters, prevents effective bonding during repair or modification, as contaminants migrate to the surface, necessitating the replacement of the composite panel, which is costly and disrupts vehicle operations.

Innovation Solution

A method involving a set-up process with a wicking medium, solvent medium, vapor barrier, and breather material, followed by a heat-assisted dispersion and evacuation process using a vacuum to remove contaminants from within the composite part, ensuring a clean bonding surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the composite panel is internally contaminated, then the bonding surface becomes contaminated and bonding fails, but replacing the panel causes added expense and operational disruption

Engineering Contradiction:
Improvebonding surface cleanlinessVSAvoidcomposite panel replacement
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent extracts internal contaminants from the composite panel by applying a cleaning solution that penetrates through the laminate layers and removes contaminants at their source location, preventing them from migrating to the bonding surface. This allows the panel to be retained and reused instead of replaced.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs preliminary cleaning of the bonding surface by removing paint, primer, and contaminants before bonding operations. This preliminary action ensures the surface is ready for bonding and prevents contamination during subsequent operations.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the bonding surface is cleaned by removing paint and primer, then the surface becomes clean for bonding, but the process becomes more complex and time-consuming

Engineering Contradiction:
Improvebonding surface cleanlinessVSAvoidcleaning process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a cleaning solution as an intermediary substance that facilitates the removal of contaminants, paint, and primer from the bonding surface. This intermediary enables effective cleaning without requiring complex mechanical removal processes.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical and chemical parameters of the cleaning solution (such as solvent type, concentration, and application method) to optimize the cleaning process. By adjusting these parameters, the patent achieves effective contaminant removal while simplifying the overall process.

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

This method effectively removes internal contaminants, allowing for successful bonding and repair or modification of composite parts without the need for replacement, reducing costs and minimizing operational disruptions.

Implementation Method 1

Fluid in liquid form can migrate into the part through the natural porosity of the composite

Methodology Applied
Scientific EffectPorosity: Porosity

Implementation Method 2

Heat causes the cleaning solution and contaminants to vaporize, allowing them to be evacuated from the composite part

Methodology Applied
Scientific EffectVaporization: Evaporation

Implementation Method 3

A vacuum is applied to the composite part, causing the vaporized cleaning solution and contaminants to be evacuated

Methodology Applied
Scientific EffectVacuum: Vacuum

Data Source

PatentEP2435548B1Method for removing fluid contaminants from a composite material
Publication Date: 2015.02.18 BELL HELICOPTER TEXTRON INC
  • EP2435548B1 patent drawingFigure 1A~1B
  • EP2435548B1 patent drawingFigure 1C~1D
  • EP2435548B1 patent drawingFigure 2A~2B

AI summary

A method of cleaning a contaminated composite part, so as to provide a surface suitable for adhesive bonding. The method includes applying a wicking medium adjacent to a surface of the contaminated composite material. Then applying a solvent medium soaked in a cleaning solution adjacent to the wicking medium. Then vapor barrier is applied adjacent to the solvent medium. Next a breather material is applied adjacent to the vapor barrier. Then a vacuum bagging film with a vacuum port is applied and sealed against the composite part. The composite part is then heated and vented to remove contaminates from the composite material.