Composite Blade Stringer Dies for Single-Tool Forming and Curing

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Solution Overview

Problem

Current manufacturing processes for composite structures require multiple tools for forming, curing, and resin infusion, leading to increased manufacturing time, tool investment costs, storage space requirements, and potential inconsistencies during material transfer.

Innovation Solution

A forming and curing tool that integrates forming and curing functions, using a pair of dies with clamp blocks and a tool lid to create a curing chamber, allowing simultaneous forming and curing of composite blade stringers with optional resin infusion, utilizing a forming device and press to apply pressure and heat.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple tools are used for forming, curing, and resin infusion, then each process can be performed with dedicated tooling, but manufacturing time increases and tool investment costs increase

Engineering Contradiction:
Improveprocess reliabilityVSAvoidmanufacturing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent combines forming and curing tools into a single integrated tooling system. The forming die includes integrated heating elements and vacuum pathways that allow the same tool to perform both forming and curing operations, eliminating the need to transfer parts between separate tools and reducing manufacturing time.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The forming die is designed with multi-functionality, incorporating heating zones, vacuum pathways, and resin infusion capabilities within the same tooling structure. This universal tool performs multiple functions (forming, heating, vacuum degassing, resin infusion, and curing) that traditionally required separate dedicated tools.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If multiple tools are used for forming, curing, and resin infusion, then specialized functions can be performed, but tool investment costs and storage space requirements increase

Engineering Contradiction:
Improveprocess adaptabilityVSAvoidtool count
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges multiple tooling functions into a single integrated forming die structure. The die includes combined forming surfaces, heating elements, vacuum pathways, and resin infusion ports that allow one tool to replace what would traditionally require multiple separate tools for forming, curing, and resin infusion operations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The forming die is designed as a universal tool that can perform multiple processes including forming, heating, vacuum degassing, resin infusion, and curing. This multi-functional design reduces the total number of tools required while maintaining the adaptability to perform specialized functions that were previously achieved through dedicated tooling.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of manufacture

If multiple tools are used for forming and curing, then specialized processing can be applied, but manufacturing precision may be compromised due to material transfer inconsistencies

Engineering Contradiction:
Improveprocess specializationVSAvoidmaterial consistency
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent eliminates material transfer between tools by integrating forming and curing operations within the same die structure. The forming die includes integrated heating zones and vacuum pathways that maintain continuous contact with the part throughout the forming and curing processes, preventing inconsistencies that arise from transferring materials between separate tools.

Inventive Principle:
Principle #5Merging (Combining)

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

Reduces manufacturing time, minimizes tool count and storage needs, and ensures consistent material formation by integrating forming and curing steps, thereby enhancing production efficiency and reducing capital costs.

Implementation Method 1

a press configured to hold and move the first die, the second die, and the tool lid relative to each other

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 2

a first die with a heating system and a first forming surface

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

the first die further comprises a number of vacuum paths through the first die, and the second die further comprises a number of vacuum paths through the second die

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 4

the tool lid comprises a number of resin inlets

Methodology Applied
Scientific EffectResin infusion: Permeation

Data Source

PatentEP4424502B1Blade stringer forming methods and tooling
Publication Date: 2025.12.24 THE BOEING CO
  • EP4424502B1 patent drawingFigure 1
  • EP4424502B1 patent drawingFigure 2
  • EP4424502B1 patent drawingFigure 3

AI summary

A first cut and kitted material is held against a first flange face of a first die. A second cut and kitted material is held against a second flange face of a second die. The method simultaneously forms the first cut and kitted material against a first blade face of the first die and the second cut and kitted material against a second blade face of the second die. The first cut and kitted material and the second cut and kitted material are clamped between the first die and the second die after forming the first cut and kitted material and the second cut and kitted material. A composite stringer preform comprising the first cut and kitted material, the second cut and kitted material, a noodle, and a base material is cured while the composite stringer preform is against the first forming surface and the second forming surface.