Pre-Dosed Fastener Sealant Shell for Faster Aircraft Assembly

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The application of sealants to a large number of fasteners in aircraft assembly is time-consuming, costly, and prone to waste due to the need for precise application and the potential for foreign object debris contamination.

Innovation Solution

A fastener with a curable sealant material dose coated on its exterior surface, encased in an at least partially-cured protective shell that ruptures during installation, releasing the sealant exactly where needed and eliminating the need for separate sealant application.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If sealant is applied separately to each fastener in aircraft assembly, then precise sealant application can be achieved, but manufacturing time and labor costs increase significantly

Engineering Contradiction:
Improvesealant application precisionVSAvoidmanufacturing speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent combines the sealant application function with the fastener itself by pre-coating the fastener with curable sealant material. This merging eliminates the need for separate sealant application steps, allowing both fastening and sealing to occur simultaneously during a single installation operation, thereby resolving the contradiction between precision and productivity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sealant material is applied to the fastener in advance during fastener manufacturing, before the fastener is installed into the aircraft assembly. This preliminary action ensures that the sealant is already in position and properly dosed, eliminating the need for time-consuming on-site sealant application while maintaining precise application quality

Inventive Principle:
Principle #10Preliminary action

2Productivity

If sealant is applied in advance to fasteners, then manufacturing time is reduced, but the sealant may cure before installation causing waste

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidsealant waste
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent utilizes the curable nature of the sealant material, changing its state from uncured (during storage and handling) to cured (after installation). This parameter change allows the sealant to remain stable and non-viscous during pre-application, preventing premature curing and waste, while enabling proper adhesion and sealing function after installation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a protective shell or coating that encases the pre-applied sealant material on the fastener. This intermediary layer protects the sealant from environmental factors and prevents premature curing during storage and handling, allowing the sealant to remain in a stable, non-cured state until the actual installation occurs

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If manual sealant application is used for thousands of fasteners, then flexibility is maintained, but labor costs and contamination risk increase

Engineering Contradiction:
Improveapplication flexibilityVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The fastener is made self-service by pre-coating it with sealant material during manufacturing. The fastener itself carries and applies the sealant, eliminating the need for separate manual sealant application operations. This self-service approach maintains adaptability while dramatically reducing labor requirements and contamination risk

Inventive Principle:
Principle #25Self-service

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 significantly reduces manufacturing time and costs by ensuring the right-sized sealant dose is applied simultaneously with fastener installation, minimizing waste and foreign object debris issues.

Implementation Method 1

an at least partially-cured protective shell configured to substantially completely encase the curable sealant material dose within the at least partially-cured protective shell

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Implementation Method 2

a curable sealant material dose configured to coat a fastener exterior surface region of the fastener exterior surface

Methodology Applied
Scientific EffectCoating: Coatings

Implementation Method 3

the at least partially-cured protective shell configured to rupture during installation of the fastener into the aircraft pre-assembly

Methodology Applied
Scientific EffectPressure-induced rupture: Pressure Increase

Implementation Method 4

a curable sealant material dose including an at least partially-cured protective shell

Methodology Applied
Scientific EffectCuring: Photopolymerisation

Data Source

PatentEP4534861A1Pre-dosed fasteners with incorporated sealant dose for wet sealant application and method
Publication Date: 2025.04.09 THE BOEING CO
  • EP4534861A1 patent drawingFigure 1
  • EP4534861A1 patent drawingFigure 2~4B
  • EP4534861A1 patent drawingFigure 3A~3D

AI summary

Fasteners pre-dosed with a curable sealant material encased within an at least partially-cured rupturable protective shell and methods are disclosed for the application of a selected curable sealant material dose to an aircraft assembly that is delivered simultaneously to an aircraft assembly location during fastener installation.