Thermoset Composite Curing with External Heating and Pressurization
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Solution Overview
Problem
The existing methods for curing thermoset composite parts in autoclaves are inefficient due to the time required to heat the parts before applying consolidation pressure, which significantly impacts the production rate.
Innovation Solution
A method involving a heating assembly that includes a cure tool and heating blankets to heat the thermoset composite parts to a predetermined temperature outside the pressurization vessel, followed by applying consolidation pressure within the vessel, and then cooling the parts outside the vessel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If heating is performed inside the autoclave before applying pressure, then the composite part reaches the required curing temperature, but the overall cure cycle time increases significantly
Solution Approach 1:
The heating assembly pre-heats the composite part to a predetermined temperature before the part is placed in the autoclave. This preliminary heating action reduces the time required for temperature ramp-up during the curing cycle, directly addressing the contradiction by achieving the required temperature earlier and maintaining it during pressurization.
Solution Approach 2:
The curing process is segmented into distinct phases: pre-heating outside the autoclave, pressurization at temperature, and cooling. The heating assembly is removed after pre-heating, separating the heating function from the pressurization vessel. This segmentation allows independent optimization of each phase, reducing total cycle time.
2Device complexity
If the autoclave is used for both heating and pressurization, then a single vessel handles the entire curing process, but the production rate decreases due to extended cycle times
Solution Approach 1:
The heating function is extracted from the autoclave system and performed by a separate heating assembly. The heating assembly is removed from the autoclave after pre-heating, allowing the autoclave to focus solely on pressurization. This extraction eliminates the time penalty of heating within the pressurization vessel and enables parallel processing operations.
Solution Approach 2:
The system transitions from a static autoclave-based curing process to a dynamic multi-stage process where the heating assembly is temporarily introduced for pre-heating, then removed for pressurization. This dynamic approach optimizes the functionality at each stage, improving overall productivity.
3Temperature
If cooling is performed inside the pressurization vessel, then the composite part is cooled under pressure, but the time required for the cooling phase extends the overall cure cycle
Solution Approach 1:
The cooling phase is segmented from the pressurization process. After pressurization is complete, the heating assembly is re-introduced to actively cool the composite part, rather than relying on passive cooling within the autoclave. This active cooling segmentation reduces the time required to return the part to ambient temperature.
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 reduces the overall cure cycle time by allowing separate heating and cooling processes outside the pressurization vessel, optimizing processing rates and minimizing time spent within the vessel.
Implementation Method 1
The cure tool may include a thermally conductive tool surface, and the tool surface may include a first surface configured to contact at least the portion of the thermoset composite part and a second surface configured to contact at least a portion of the one or more heating blankets, such that, heat generated by the one or more heating blankets is transmitted through the tool surface to heat at least the portion of the thermoset composite part in contact with the tool surface to the predetermined temperature.
Implementation Method 2
At least one of the one or more heating blankets may be an inductive heating blanket including a smart susceptor, and the smart susceptor may have a Curie temperature corresponding to the predetermined temperature.
Implementation Method 3
placing the heating assembly within a pressurization vessel; using the pressurization vessel to apply a consolidation pressure to the thermoset composite part until cure of the thermoset composite is complete
Data Source
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AI summary
A method for curing a thermoset composite part (100), including placing the composite (100) part within a heating assembly (200) and using the heating assembly (200) to heat the composite part (100); placing the heating assembly (200) within a pressurization vessel (300) and applying a consolidation pressure; removing the heating assembly (200) from the pressurization vessel (300) and using the heating assembly (200) to cool down the composite part (100).