Method for producing thermosetting composite parts by drape forming of preimpregnated material

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Solution Overview

Problem

Current methods for producing thermosetting composite parts through drape forming require intermediate vacuum compactions, which are costly, time-consuming, and reduce productivity, and still necessitate polymerization under pressure in an autoclave for optimal performance.

Innovation Solution

A process involving partially polymerized prepreg material with a degree of polymerization between 10% and 60%, allowing for drape forming without intermediate compactions and potentially eliminating the need for autoclave polymerization, by heating and pressing the material above its glass transition temperature to create open voids for efficient air drainage during final polymerization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If intermediate vacuum compactions are performed during drape forming, then air trapped between plies is evacuated and layer holding is improved, but productivity decreases and process complexity increases

Engineering Contradiction:

Improvelayer holding qualityVSAvoidlay-up rate

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The resin is partially polymerized in advance to a degree of 10-60% before drape forming, creating preliminary tack that eliminates the need for intermediate vacuum compactions during the laying-up process, thereby maintaining high productivity while ensuring reliable layer bonding

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The degree of polymerization is changed from the conventional <20% to a higher range of 10-60%, which fundamentally alters the resin's tack properties and enables self-bonding during drape forming without requiring intermediate compaction steps

Inventive Principle:

Principle #35Parameter changes

2Reliability

If intermediate vacuum compactions are performed during drape forming, then layer bonding is improved, but process complexity and cost increase

Engineering Contradiction:

Improvelayer bonding qualityVSAvoidprocess complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The resin is partially polymerized in advance to a degree of 10-60% before drape forming, creating preliminary tack that eliminates the need for intermediate vacuum compactions during the laying-up process, thereby simplifying the overall process while ensuring reliable layer bonding

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The intermediate vacuum compaction step is extracted and removed from the drape forming process entirely, replacing it with the preliminary polymerization approach that achieves the same bonding quality without the complex vacuum equipment and multiple stopping points

Inventive Principle:

Principle #2Taking out (Extraction)

3Stability of the object's composition

If conventional prepreg with low polymerization degree is used, then storage stability is maintained, but intermediate compactions are required during drape forming

Engineering Contradiction:

Improvestorage stabilityVSAvoiddrape forming simplicity

Core Design Contradiction:

Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The degree of polymerization is optimized to a specific range of 10-60%, which is high enough to provide preliminary tack for easy drape forming without compromising storage stability, eliminating the need for intermediate compactions while maintaining both storage and processing performance

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 approach eliminates intermediate compactions, maintains high lay-up rates, and allows for final polymerization in an oven instead of an autoclave, reducing energy costs and simplifying the process while ensuring the quality of the composite parts.

Implementation Method 1

heating the material, at a temperature above the glass transition temperature of the prepreg state in question

Methodology Applied

Scientific EffectGlass transition:

Implementation Method 2

pressing the laid-up material

Methodology Applied

Scientific EffectPressure:

Implementation Method 3

cooling the laid-up material, making it possible to return to a temperature below the glass transition temperature of the prepreg state in question

Methodology Applied

Scientific EffectGlass transition:

Implementation Method 4

partially polymerizing the resin to a degree of polymerization of between 10% and 60%

Methodology Applied

Scientific EffectPolymerization:

Data Source

PatentUS9821491B2Method for producing thermosetting composite parts by drape forming of preimpregnated material

Publication Date: 2017.11.21 AIRBUS (SAS)

AI summary

A process for fabricating a partially polymerized prepreg material. Fibers are impregnated with thermosetting resin. The resin is partially polymerized to a degree of polymerization between 10% and 60%. The thermosetting composite parts are produced by drape forming of the prepreg material. The material laid-up in the form of tapes and heated at a temperature above the glass transition temperature of the prepreg state. The laid-up material is pressed and cooled to return the laid-up material to a temperature below the glass transition temperature of the prepreg state in question.