Co-bonding Thermoset Composites via Partial Cure State

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Solution Overview

Problem

Existing methods for curing thermoset composites are resource-intensive and inefficient, particularly in co-bonding processes, where large layup mandrels and heating assemblies are underutilized due to excessive curing times beyond what is necessary for achieving desired mechanical properties.

Innovation Solution

A method that involves partially curing a first thermoset composite to a target state of cure based on maximum temperature and elapsed time, then combining it with a second thermoset composite to form a partially cured assembly, which is subsequently heated to bond and fully cure the assembly, optimizing curing time and resource usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If thermoset composite is fully cured using traditional heating methods, then complete curing and desired mechanical properties are achieved, but curing time is excessively long and factory resources are underutilized

Engineering Contradiction:
Improvecuring completenessVSAvoidcuring time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The first thermoset composite is partially cured before combination with the second composite. This preliminary curing action achieves sufficient mechanical properties without complete curing, reducing overall process time while maintaining reliability through the subsequent co-bonding cure cycle that completes the curing process for both components simultaneously.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If thermoset composite is fully cured using traditional methods, then desired mechanical properties are achieved, but factory equipment and capacity are not efficiently utilized

Engineering Contradiction:
Improvemechanical propertiesVSAvoidequipment utilization
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention merges the curing processes of two separate thermoset composites into a single co-bonding cure cycle. By combining the first partially cured composite with the second uncured composite and curing them together, the method achieves complete curing of both components in one operation, maximizing equipment utilization and productivity.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If traditional curing methods are used for thermoset composite, then complete curing is ensured, but the process is resource-intensive and exceeds necessary curing time for desired properties

Engineering Contradiction:
Improvecuring completenessVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The first thermoset composite is cured to a partial state (sufficient but not complete) before combination with the second composite. This partial curing action consumes less energy than full curing while achieving the necessary mechanical properties, with the energy-intensive complete curing performed once during the co-bonding process for both components.

Inventive Principle:
Principle #16Partial or excessive 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

This approach significantly reduces curing time by up to 60% compared to traditional methods, enhancing equipment utilization, decreasing manufacturing and labor costs, and producing a cured composite part with similar mechanical properties to fully cured parts, while minimizing contamination and residue.

Implementation Method 1

partially curing the first thermoset composite to a target state of cure (SOC) to define a first partially cured thermoset composite... based, at least in part, on a maximum temperature of the first thermoset composite during the partially curing and on an elapsed time that an actual temperature of the first thermoset composite is greater than a threshold temperature

Methodology Applied
Scientific EffectThermal curing: Heating

Implementation Method 2

heating the partially cured TSC assembly to bond the first partially cured TSC to the second TSC within an interface region, to cure the partially cured TSC assembly, and to produce a cured composite part

Methodology Applied
Scientific EffectThermal bonding: Heating

Data Source

PatentEP3595874B1Methods of co-bonding a first thermoset composite and a second thermoset composite to define a cured composite part
Publication Date: 2022.05.25 THE BOEING CO
  • EP3595874B1 patent drawingFigure 1~2
  • EP3595874B1 patent drawingFigure 3
  • EP3595874B1 patent drawingFigure 4

AI summary

Methods of co-bonding a first thermoset composite (TSC) and a second TSC to define a cured composite part are disclosed herein. The methods include partially curing the first TSC to a target state of cure (SOC) to define a first partially cured TSC. The partially curing is based, at least in part, on a maximum temperature of the first TSC during the partially curing and on an elapsed time that an actual temperature of the first TSC is greater than a threshold temperature. The methods further include combining the first partially cured TSC with the second TSC to define a partially cured TSC assembly and heating the partially cured TSC assembly to bond the first partially cured TSC to the second TSC, cure the partially cured TSC assembly, and produce a cured composite part.