The curing process is key to converting a loose mass of fibres and resin into an advanced engineering composite material.
The curing process applies the energy to cross-link or melt the polymer matrix and the pressure to consolidate the resulting composite. Autoclaves are traditionally used to apply this heat and pressure, but they present certain inherent drawbacks that may be overcome with out of autoclave, advanced curing technologies.
These drawbacks result in the curing process often representing the limiting factor in composite manufacturing and limiting the wider adoption of composite materials.
Advanced curing technologies
The AMRC is pursuing a number of alternatives to the use of autoclaves, including:
- Microwave heating.
- Hot pressing.
- Directly heated tooling.
- In-situ consolidation during AFP.
The different technologies available will be of interest to different sectors of industry.
- Microwave curing is of key interest to the aerospace industry, with the process demonstrated to offer great savings in cure time and energy without compromise in quality.
- Hot pressing is of great interest to the automotive industry, since relatively simple parts can be formed extremely rapidly.
- Directly heated tooling has great appeal across industry sectors for parts not requiring applied pressure for lower performance components.
The AMRC is working closely with partners across industry and research, including SMEs, large multinationals, universities and other research institutes, such as:
- Boeing directed work.
- Microwave curing of panels for NCC to benchmark against traditionally cured panels.
- Work with SHD Composites to develop microwave-friendly resins.
- Work for NetComposites hot pressing bio fibre thermoplastic panels.
- EPSRC application with University of Sheffield for direct electric cure investigation.
- Supervision of MSc student with TEKS UK in induction heating.
Monitoring thermal distribution
Researchers at the AMRC Composite Centre identified the opportunity to expand their capabilities for monitoring thermal distribution when curing composites in their industrial microwave oven.
The team can now utilise the full chamber to improve visibility, allowing them to accelerate research into microwave curing as a manufacturing process for industrial implementation.