Expandable Tooling for Composite Curing

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Solution Overview

Problem

The manufacturing process for composite materials often relies on industrial autoclaves, which create bottlenecks due to limited capacity and require transportation of materials and components, leading to inefficiencies and increased costs.

Innovation Solution

The use of expandable tooling systems, which include a constraining container and a thermally-activated expandable element, allows for the application of pressure to composite workpieces during curing without the need for an autoclave. The expandable element, such as pellets, expands when heated, providing the necessary pressure for consolidation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional industrial autoclave curing is used, then composite materials can be cured under controlled temperature and pressure, but manufacturing throughput is limited by autoclave capacity and transportation requirements

Engineering Contradiction:

Improvecuring qualityVSAvoidmanufacturing throughput

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The autoclave system is segmented into portable, distributed heating and pressure application devices. Instead of one large autoclave, multiple smaller heating elements and expandable pressure-generating elements are distributed throughout the workpiece, enabling parallel processing and eliminating transportation bottlenecks.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention transitions from centralized 3D autoclave processing to distributed surface-level heating and pressure application. By applying heat and pressure simultaneously from multiple surfaces and directions, the system achieves autoclave-quality curing without requiring large-volume enclosed chambers.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If traditional industrial autoclave curing is used, then composite materials can be cured under controlled temperature and pressure, but transportation of materials and components is required

Engineering Contradiction:

Improvecuring qualityVSAvoidtransportation requirement

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The essential curing function is extracted from the large autoclave environment and implemented through localized heating elements and pressure-generating elements applied directly to the workpiece. This eliminates the need for transporting materials to and from a centralized autoclave facility.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The workpiece itself becomes part of the curing system by incorporating or being surrounded by heating elements and expandable pressure elements. The system performs curing in situ, eliminating the need for external transportation and specialized autoclave facilities.

Inventive Principle:

Principle #25Self-service

3Productivity

If expandable elements are used to apply pressure during curing, then autoclave capacity limitations are overcome, but additional elements and process steps are required

Engineering Contradiction:

Improvemanufacturing throughputVSAvoidtooling complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The expandable elements utilize phase change (from compact unexpanded state to expanded state) to generate pressure. This parameter change allows the same element to serve multiple functions: occupying minimal space during handling and providing distributed pressure during curing, thereby simplifying the overall system.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The expandable pressure-generating elements undergo phase transition from a compact unexpanded state to an expanded state when exposed to heat or fluid. This phase transition enables the elements to generate the necessary curing pressure while maintaining portability and ease of handling before deployment.

Inventive Principle:

Principle #36Phase transitions

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 enables efficient curing of composite materials outside of an autoclave, improving throughput, reducing transportation costs, and allowing for the manufacture of complex shapes without the need for custom tooling.

Implementation Method 1

expanding the expandable element by heating the thermally-activated expandable element to at least a predetermined temperature

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

curing the composite workpiece while the expanded element applies pressure to the workpiece

Methodology Applied

Scientific EffectThermal curing: Heating

Data Source

PatentUS12208585B2Expandable tooling systems and methods

Publication Date: 2025.01.28 THE BOEING CO

AI summary

Methods of manufacturing composite workpieces that include adding an expandable element to an internal volume of a constraining container proximate to a uncured composite workpiece supported on a rigid form, where the expandable element is configured to expand when a predetermined change is produced in an attribute of the expandable element; expanding the expandable element by producing the predetermined change in the attribute of the expandable element, so that an expansion of the expandable element applies pressure to the workpiece supported on the rigid form within the internal volume, and curing the composite workpiece while the resulting pressure is applied to the workpiece supported on the rigid form.