Resin Infusion Tool Pressure Control During Composite Cure

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Solution Overview

Problem

Conventional systems for forming composite structures are time- and labor-intensive, requiring precise machined tooling and hard stops, making it difficult and expensive to produce high-quality composite structures at high rates with desired performance characteristics.

Innovation Solution

A system and method using a tool with an adjustable stop to maintain a predetermined pressure during resin infusion and cure, controlling tool position to account for resin shrinkage and ensure consistent pressure across the composite part.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional systems use precisely machined tooling and hard stops to control cure pressure and part thickness, then manufacturing precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvecure pressure controlVSAvoidtooling complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces static hard stops with a dynamic system using a movable tool lid and adjustable stop. The tool lid moves relative to the tool base to generate internal pressure, and the adjustable stop can be repositioned to control tool position and maintain predetermined pressure values throughout the cure process, accommodating resin shrinkage while simplifying the overall tooling design

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the control parameter from fixed mechanical hard stops to an adjustable stop system that can be repositioned. This allows the tool position to be adjusted to account for resin shrinkage during cure, maintaining constant predetermined pressure without requiring precisely machined tooling with hard stops

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If conventional systems use precisely machined tooling and hard stops to control cure pressure and part thickness, then manufacturing precision is improved, but productivity decreases due to time- and labor-intensive processes

Engineering Contradiction:
Improvepart thickness controlVSAvoidproduction rate
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The movable tool lid system allows for dynamic adjustment during the curing process to maintain constant pressure as resin shrinks. This eliminates the need for time-consuming manual interventions and complex multi-stage pressing operations, thereby improving productivity while maintaining part thickness control

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The adjustable stop system automatically maintains the predetermined pressure value throughout the cure process by controlling the tool position. The system self-regulates to account for resin shrinkage without requiring continuous manual adjustment or complex control mechanisms, reducing labor intensity while maintaining precision

Inventive Principle:
Principle #25Self-service

3Stress or pressure

If conventional systems use hard stops to control cure pressure, then pressure control is achieved, but the system cannot account for resin shrinkage during cure

Engineering Contradiction:
Improvecure pressureVSAvoidadaptability to resin shrinkage
Core Design Contradiction:
Stress or pressureVSAdaptability or versatility

Solution Approach 1:

The adjustable stop can be repositioned to accommodate changes in resin volume during curing. As the resin shrinks, the tool lid can move relative to the tool base while the adjustable stop maintains the predetermined pressure value, allowing the system to adapt to resin shrinkage while maintaining consistent pressure control

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The adjustable stop is pre-positioned to account for expected resin shrinkage during the cure process. This preliminary positioning ensures that the tool maintains the correct predetermined pressure value throughout the entire curing cycle, compensating for shrinkage before it affects the final part quality

Inventive Principle:
Principle #10Preliminary action

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

The system enables high-quality composite structures to be produced efficiently by maintaining constant pressure throughout the cure process, preventing defects and ensuring consistent quality.

Implementation Method 1

it has been discovered that constant pressure should be maintained across a resin-infused preform during cure to account for volumetric decrease during cure

Methodology Applied
Scientific EffectVolumetric decrease during cure: Phase Change

Data Source

PatentEP4438277B1Systems and methods for forming composite structures using resin infusion
Publication Date: 2026.04.08 THE BOEING CO
  • EP4438277B1 patent drawingFigure 1A
  • EP4438277B1 patent drawingFigure 1B
  • EP4438277B1 patent drawingFigure 2

AI summary

A system for forming a composite structure includes a tool for infusing a dry preform with a resin. The tool includes a tool base and a tool lid. The tool base includes a base surface. The tool lid includes a lid surface. The system includes an adjustable stop that is positioned between the tool base and the tool lid. The base surface and the lid surface form a portion of a tool cavity. The tool lid is movable relative to the tool base to generate an internal pressure within the tool cavity. The adjustable stop controls a tool position of the tool lid relative to the tool base to achieve a predetermined value for the internal pressure.